Yes, the infamous “Mr. Gee murder mystery series” trying to find and eliminate the oil pressure killer has been continued but hopefully now finally resolved.
This could take awhile so you may want to wait till you can settle into a comfy seat with your favorite beverage before you continue. Just sayin’ ……………….
As some of you may recall, last September I left all of you and poor Mr. Gee literally hanging in the Engine Room and have only just now been able to pick up the story as the hung for the mystery oil pressure killer picks up for what I sincerely hope is the LAST chapter in this far too long running series. I will be VERY happy when I can leave all the mystery writing to the true professional author onboard, my beautiful Bride who goes by the pen name Christine Kling.
The Mystery Begins:
If this is new or too long ago for you, the quick summary is that during the first sea trial taking XPM78-01 Möbius out to sea for the first time last April, the oil pressure in the Gardner 6LXB main (and only) engine, suddenly dropped from its normal 35PSI down to almost 20 and so we limped back to port at very slow speed. 
After much investigation and …..
……… stripping poor Mr. Gee completely naked, it was determined that the hired test Captain did not have the experience he claimed running of a boat with a CPP Controllable Pitch Propeller.
For reasons that will remain another mystery, soon after clearing the entrance to the port and without any notice, the Captain decided to perform a WOT or Wide Open Throttle test and pushed both throttle and pitch levers to their limits and overstressed the brand new engine, damaging the main crankshaft bearings as painfully evident here on these two connecting rod bearings and ……
……. here on the respective ConRod journals on the crankshaft, and other parts.
Once I had assessed the full extent of the damage, I contacted always super supportive and helpful Michael Harrison and his team at Gardner Marine Diesel and ordered a new crankshaft, bearings, gaskets and all the other parts needed to fully rebuild Mr. Gee a second time. 
Knowing how long it takes to get things shipped to us here in Turkey I sent that order in very quickly and was pleasantly surprised when this crate full of all the new parts and new crankshaft showed up in late May (2021)
Mr. Gee Rebuild #2
I completed that second rebuild back in June 2021 and 
Mr. Gee started up first crank as usual and oil pressure was spot on factory specs @ 35PSI. 
The last week of June we took Möbius out for a day trip to test everything out and have a chance for us to get to know all these new systems as well as some time to practice docking and slow speed maneuvering. All went well, oil pressure stayed steady at 35PSI and so we headed out for a short overnight test run and our first chance to use all the anchoring equipment. It felt SOOOOO good to be at anchor again after all these years being landlubbers and these two short sea trials clocked about 10 hours on the engine including taking it up to full load multiple times with no problem.
In this shot we’re doing 9 knots at 1500 RPM
Beginning of July our two Granddaughters, Blair (in Red) and Brynn (in Green) and their Mum & Dad flew over for a month long visit.
After a few days introducing them to live onboard Möbius, we took them out to the same anchorage for Brynn’s 7th birthday which was very special for all of us. They all loved being on the boat so they decided to join us in moving Möbius up to our new Port in Finike which is about 80 nautical miles West from where we were in Antalya. We decided to anchor again on the way up in what the Granddaughters called “Mermaid Cove” which was a spectacular little cove with sheer rock cliffs for about 300 degrees around us and all was well with the world.
Next morning the girls helped me take up the anchor and we headed on to Finike. Alas, our good fortune was not to continue as the next day on the leg up to Finike the oil pressure again started to drop. It was different this time, dropping very slowly but it continued to drop as we made our way to Finike. Fortunately the Gardner 6LXB engines have an adjustable relief valve that allows you to set the oil pressure correctly after a rebuild so I was able to adjust the oil pressure relief valve to keep the oil pressure up at or above 35 PSI to ensure that no damage occurred, but I had to do this several times as the oil pressure continued to drop so clearly the dastardly “oil pressure killer” was still at large and needed to be apprehended and given a life sentence with NO parole!
Fortunately I had designed the Engine Room with a full size hatch for the roof and reinforced this so that by putting steel beams across I could lift Mr. Gee up into the air with chain blocks and suspend him about 1 meter above the engine beds using multiple loops of Dyneema line. Having already done this once back in May for the 2nd rebuild, it didn’t take me to long to remove everything neccessary to separate Mr. Gee from the Nogva CPP servo gearbox and hoist him up high enough so I could remove the cast AL oil sump/pan to get at the main bearings, crankshaft and main lube oil pipework.
It only took me a couple of days to remove the crankshaft but I spent most of August & September with my Sherlock hat on going to every length possible to flush out and find the root cause of the dropping oil pressure and fix it once and for all. I consulted with literally the world’s experts on Gardner engines as well as my personal list of diesel engine experts from all my years working as a HD mechanic, reading and researching every manual, online forums and doing lots of experiments on the various engine parts I came to suspect and finally found the guilty party, and I will walk you through my detective work below.
Third Time’s the Charm?!
And so began the rebuild #3 and what is hopefully the last of this murder mystery series. Given all that had happened, I was in no mood to take any prisoners nor any chances so I decided to rebuild the entire “bottom end” with all new parts.
So I built a super sturdy wood crate and sent the second crankshaft back to Gardner Marine Diesel in England to be reground with all new bearing surfaces as well ordering all new main and con rod bearings, new oil pump, new oil cooler and a long list of other parts. I was able to get that all packed up and shipped off to Gardner at the end of September just before we flew over to Florida for our long overdue Gramma and Grampa time in the USA and Canada. We were gone for almost two months so I had hoped that the newly reground crankshaft and new parts would be waiting for me when I returned but Murphy and the vagaries of shipping things In/Out of Turkey conspired against me and it did not arrive until last week. (mid Jan 2022) and Rebuild #3 began.
Finding the Serial Oil Pressure Killer
OK, with that as a quick overview of the chronology of this murder mystery, let’s get back to the story of how I eventually tracked down the elusive serial Oil Pressure Killer.
The Oil Pressure Killing Begins: April 2021
For reference, let me briefly go back and review what had happened the first time the Oil Pressure Killer struck on that first sea trials back in April 2021. As you recall, the oil pressure had dropped very quickly to 20 PSI and after tearing poor Mr. Gee completely apart this is what the crankshaft bearings looked like.
Yikes! With less than 4 hours total run time on the new engine, that loss of oil pressure was catastrophic and had completely worn away the protective lining of the bearings and severely scored the crankshaft journals.
This is how the Gardner main and connecting rod bearings are constructed, which is pretty much the same as most diesel engines and so you can see that the loss of oil pressure along with the huge loads when both throttle and pitch levers were pushed past their max positions, both the overlay and Nickel layers had been completely worn away.
Here is a shot of all seven of the main crankshaft bearing shells after the disastrous sudden loss of oil pressure on that first sea trial run. You can see how the bearings are completely worn out after less than 4 hours running since they were new.
For reference, main bearings should last for several hundred thousand miles on average diesel engines and much longer on Gardner engines. When I removed the bearings on the original engine which had been running in a working tug boat for over 46 years, they had just barely started to show a wee bit of copper.
With this much wear on all these Main and Con Rod bearings, the consensus conclusion was that the rapid wear allowed oil to leak out the sides of each bearing lowering the oil pressure which led to more wear which led to more loss of pressure and that cycle continued till I stopped the engine.
The next step was clear if a bit painful; completely rebuild the engine again! I had been in almost daily contact with Michael and his team at Gardner Marine Diesel and he soon had a new shipment on its way to me with a freshly ground replacement crankshaft, new Main & Con Rod bearings, all gaskets, seals and everything I needed to do Rebuild #2. That crate finally arrived in May and as per the outline above, I completed that second rebuild at the end of June 2021, just in time for the arrival of our Granddaughters and family.
The Oil Pressure Killer strikes again! July 2021
You’ve read about the fateful trip moving Möbius over to Finike Marina in July when the oil pressure started to drop again. This time there was no overloading and the pressure had stayed steady 35 PSI for the first 13 hours or so of engine run time but it then began to drop off again. Slowly this time, but steadily dropping. Fortunately I was monitoring this all very closely and was aware of the decline as soon as it happened and this time I was able to use the Oil Pressure Relief Valve to keep adjusting the oil pressure to make up for the loss and keep the oil pressure at 35 PSI and avoid damaging the engine. However, clearly there was a major problem and I immediately knew yet another rebuild was in my future!
I didn’t want to spoil the long awaited time with Lia, Brian, Brynn and Blair, so we didn’t say anything about it and rented a van to take us on a two week driving tour of Turkey. As per this shot, a good time was had by all.
Perhaps the most memorable stop on our driving tour was the three days we spent in Kapadokya where at dawn we all went on a 90 minute hot air balloon ride.
Seeing the sunrise over the surrealistic topography below was beyond words and only one of several other awemazing adventures we had together in July.
Tracking Down the Killer
We dropped off the family at an airport outside of Kapadokya and we drove the 9 hours back to Finike where Möbius and Mr. Gee were patiently awaiting for me to pick up where I had left off with the unsolved mystery. We now return to those two months of intense detective work in August and September and how I managed to finally track down the elusive serial Oil Pressure killer. 
I soon had Mr. Gee suspended yet again from the Engine Room overhead hatch and it didn’t take me too long to get the crankshaft out so the investigation could begin in earnest.
Good news was that as you can see here, the bearings were not worn and the crankshaft journals were also untouched. Bad news was that clearly the loss of oil pressure was NOT due to wear on the bearings, so they were off the hook as the guilty party.
Wanting to leave nothing to chance and double check EVERY thing, I took the time to physically measure the gap on each of the Main and Con Rod bearings so that I would know eXactly what the clearance is and confirm for sure that all the bearings were still like new.
I’ve done this many times rebuilding engines over the years and is done using an ingeniously simple product called “Plastigauge” which is a special string like pliable plastic material which you lay along the bearing journal and then reassemble the bearing cap, torque it down fully and then carefully remove the bearing cap to reveal the compressed bit of Plastigauge. There is then a scale you use to measure the width of the flattened Plastigauge strip which tells you the exact size of the gap or clearance.
It is a simple, though time consuming process but gives you a direct measurement of the bearing clearance. 
Here is what the compressed Plastigauge looked like on Con Rod #3
which works out to be 0.05mm or 0.00197”. Gardner specifications for clearance when brand new is 0.0015-0.0020 which is again good news and bad news at the same time!
Good news the bearings and crank were still in like new condition.
Bad news is that the serial killer is still at large!
When faced with conundrums like this I go back to basics and start sketching out, both on paper and in my head, how a system works from beginning to end. So back to the drawing board I went.
Simple is Good Right?
Part of what makes Gardner engines so famously long lasting and sought after is their simplicity and the lubrication system is a perfect example. KISS and simple is good right? It definately is but in a case like this it is also very puzzling when you are trying to figure out how it is possible that oil pressure is escaping somewhere in such a very basic and “simple” lubrication system?!?!
For example, unlike modern engines where the lubrication system is mostly all internal and hidden, Gardner engines have most of their lubrication system flowing through beautiful copper pipes such as those you see here, which are all mounted on the exterior of the engine. This makes it very easy to check and obvious to see if there are any seals leaking there.
More Good/Bad news; all dry, clean and fully sealed. No leaks here.
Drat!
OK, so no oil leaks in any of the external pipes and no bearing wear so no leaks there.
No oil was exiting the engine and the oil level stayed the same so the oil pressure had to be leaking out internally but how and where?
The only internal connections in the 6LXB lubrication system which are hidden from view is the lubrication pipework that carries pressurized oil to each of the Main bearings along the length of the crankshaft, so that’s where I next aimed my investigative attention and microscope.
Gardner also produced phenomenally illustrated and detailed manuals which I have gathered up over the years and have now become intimately familiar with every page! For example, this coloured illustration below from one of my manuals, shows how the oil circulates through the lubrication system in a 6LXB.
The Brown lines shows the path of the pressurized oil as it leaves the oil pump in the lower right corner, running up through external copper pipes to the Oil Pressure Relief Valve (upper right), through the oil filter and then back down another external copper pipe which delivers the oil into …..
…. the bolted on cast iron fitting on far Left here, which connects up to all the steel pipes and cast iron T fittings bolted to each Main Bearing cap.
Here is what that pipework system looks like this when unbolted and removed from the engine.
If you refer back to the coloured diagram above, this set of pipework is shown in the Brown horizontal lines along the bottom of the crankshaft.
As is common on most diesel engines, once pressurized oil is delivered to the crankshaft main bearings, there are passageways drilled inside the crankshaft which allow pressurized oil to then travel out to each Con Rod bearing, then up through the Con Rod itself to lubricate the piston or Gudgeon pin and then the oil falls by gravity back into the oil sump where the cycle continues.
All as shown in the coloured illustration above.
The Search Intensifies
Trying to keep this a bit shorter than War & Peace, I am leaving out many days filled with investigating every millimeter of Mr. Gee’s lubrication system. I continued discussing this with the team at Gardner, my dear friend Greg who has the best mind and experience with diesel engines I know as well as many others (thanks!) via Email, voice and video calls and sending them probably more than 100 photos I had been taking throughout my sleuthy searching.
As each part of the lubrication system from pipes to pumps, filters to seals, was fully explored, tested and put under the microscope they all checked out fully and were scratched off of my list of possible suspects. The only remaining possibility was a leak internally that was bleeding off the pressurized oil and letting it drain back into the oil pan.
I took a bit of a scientific approach of using the evidence I had collected throughout the whole experience during each of the rebuilds, sea trial data, research in manuals and online and then coming up with LOTS of different tests to gather more data.
Like this setup I created to pressure test all the oil tubes inside the crankshaft for any leaks due to cracks or otherwise. I filled each tube with engine oil, heated it to about 75C to replicate even hot engine oil operating temperatures and then pressurized to over 100PSI with this bicycle pump setup.
More Good/Bad news as all tests showed no leaks. Double drat!
Having eliminated every other seeming possible suspect, that oil pipework kept coming up as the only remaining suspect and yet it too seemed to be so simple and robust. The experts at Gardner have rebuilt thousands of XLB’s over the years and never had any problems remotely similar but the more I went around and around the more I became convinced that the leaks had to be somewhere in that seemingly simple pipework on the Main Bearings so I rolled up my sleeves and spent the next few weeks maniacally devoted to finding where and then why the oil pressure was escaping inside Mr. Gee and inside my little brain.
Even though Gardner and others kept taking it off the list, I kept coming back to that lube oil pipework as the prime, and in my mind now, only possible suspect and let me show you what I eventually discovered as I dug into this.
Each of those cast iron fittings bolts to one of the 7 Main Bearing caps and there is a small donut shaped rubber O-ring that keeps this connection fully sealed.
One of my tests along the way had been this setup where I bolted each of these cast iron fittings to their respective Main Bearing Caps with one of the steel pipes inserted into its O-ring sealed hole in the fitting and the other end of the pipe capped off. I fabricated a threaded adaptor that I could insert into the oil hole in the Cap and pressurized this with my bicycle pump to test for leaks and they all seemed to hold but I was still not sure so I kept looking closer and closer ……………………
At first glance, all looked well with those rubber O-rings but lets look closer …….
Hmmmm ……
…….. something’s not right here, let’s look closer …..
……. what’s going on here? Looks like this O-ring has been getting squished or pinched?
OK says Holmes, we need to quite literally put this under the microscope.
I’m going to take some “literary liberty” to again condense down what was more than a week’s worth of truly microscopic investigation, more Emails, more phone calls and more testing but here’s the quick recap.
As Christine will quickly confirm with a roll of her eyes, I’m a bit of pack rat when it comes to engine and boat parts and this case shows why. I had kept all the O-rings, bearings and other parts from all the previous rebuilds so I was able to now dig them up and put all of them under the microscope and here is what I found.
These are the O-rings from the very first time I rebuilt Mr. Gee in 2020 and were in the engine when the first sudden loss of oil pressure occurred after only 2 hours of run time. You will notice that there is the same deformation of these O-rings that I noted above.
Here is the set of O-rings that were new when installed in the 2nd rebuild and then experienced the second slower drop in oil pressure in June 2021after about 13 hours of run time.
Here is one of those O-rings as seen through my 10x magnification lens.
Yikes! Do we have flesh eating bacteria’s evil twin on a rubber diet?
Eureka! I think we’ve found the Oil Pressure Killer!
Well, sort of. This seemed to clearly be WHERE the oil was most likely escaping and causing the drop in oil pressure. This evidence seemed to support the evidence of how the oil pressure stayed at 35 PSI for the first few hours and then slowly began to drop as these O-rings wore away more and more, letting more and more pressure escape. But the real question became WHY was this wear happening???
More calls and Emails ensued with Gardner who deserve medals of honour for service SO above and beyond any reasonable expectations which led them to contact the factory that makes these O-rings to see if there was any chance of a bad batch of rubber or any other explanation for this catastrophic wear and failure. I measured and tested all the O-rings on my end including many of the new ones I had in my Gardner parts department and they all came through with flying colours for all their dimensions, hardness, etc. The manufacturer confirmed that there had been no change in the rubber formula nor any recalls or other examples of any problems and GMD checked their records which showed that they had rebuilt more than 100 6LXB’s using these same batches of O-rings before and after both my batches and they were all running fine with no reports of any loss of oil pressure, so they were all as perplexed as I was.
So it was back to scientific mode for me. I took some brand new O-rings and ran several experiments where I would install them in their cast iron fittings and torque them down to their respective Main Bearing Caps. I tried some assembled #2 dry, #3 with some with a light coating of engine oil as is normal and #1 coated with the Gardner “WellSeal” gasket compound in order to test if there was some kind of a chemical reaction going on. 
I left these overnight and then disassembled them the next day and at first glance as in the photo above, it looked like all the O-rings were fine and that there was no difference between tests 1 to 3. But the microscopic view showed otherwise and I could see that even these brand new O-rings were somehow being “pinched” and split just by being assembled and torqued down to factory settings. I repeated this experiment three more times with the same results every time so I could not yet explain why this was happening, I could at least replicate the problem and see that the O-rings were being pinched and sliced open upon assembly and then being worn away more and more as the pressurized oil began to flow through and around them.
Another flurry of Emails, photos and calls with Gardner who could only join me in disbelief and mystery. However, true to form, Michael very diligently had a new batch of O-rings made up to even tighter tolerances and shipped those to me. As soon as these arrived I tested them the same as I had all the other new O-rings from the previous rebuilds by bolting to their MB Caps on my workbench as shown above and and was DELIIGHTED to find that when I disassembled them the next day, they all came out unscathed with no pinching or splitting. Whew!!!
By now it was mid September and the clock was ticking in my ear because we were flying out for the Nauti Grandparents North American 2021 tour on October 5th. While the root cause or “killer” was yet to be apprehended I knew that I could not just replace the O-rings with more new ones and put the engine back together for a third time so I made the call to replace the whole bottom end and lube oil system with all new parts and start over from scratch. I put in the order with Michael at GMD for all new bearings, gaskets, oil pump, pressure relief valve and so on and then crated up the 2nd crankshaft to send it back to Gardner to have all the journals machined.
That second crankshaft I had just removed was still in new condition having been freshly ground before it was sent to me back in May and the bearings were all still in like new condition but I simply had to completely eliminate every possible source of leakage so I bit this very expensive and time consuming bullet and put it all behind me so I could move on with getting Mr. Gee back up and running permanently.
Killer Hiding in Plain Sight?
While it did feel good to have found WHERE the oil pressure was leaking out causing the dropping oil pressure, I HAD to figure out WHY this was happening so I could fix the root problem and be confident that Mr. Gee would have perfect oil pressure from now on. Our lives quite literally depend on Mr. Gee in many situations so this is not mere curiosity on my part!
After many more sleepless nights going over and over every possible explanation for the loss of oil pressure, the splitting O-rings, and coming up with every possible theory as to WHY those O-rings were being so rapidly worn away, I again went back to basics and started testing and re-testing every possibility. In particular I tried to make NO assumptions and check EVERY detail and sure enough one of those assumptions turned out to be the key bit of evidence that led me to the true culprit.
Remember those simple cast iron fittings and how the O-rings seal them? The mating surfaces of the fitting and the Main Bearing Cap are flat with a square groove cut into the fitting where the O-ring sits. The O-ring is thicker than the depth of that groove so that when you bolt the fitting down onto the Cap, the O-ring squishes and seals the oil flowing through from being able to escape. 
Reasonable to assume that those two mating surfaces are flat right? No need to check for that!
Well I just happened to check and sure enough the surface of all those fittings was NOT flat
It will have to remain a mystery as to why this happened but it turned out that those cast iron fittings that bolt to the Main Bearing Caps were warped. Bowed would be more accurate as even when they were fully torqued down tight as they are here, there was a gap in the middle section where the O-rings sit. In further testing these gaps ranged from 0.3-0.5mm or 0.012-0.02” whereas they should be touching and sealing themselves.
Why is this such a big deal that there is gap between these two metal surfaces?
Well, with the metal surfaces not touching around where the O-ring seals, and with the O-rings being split open for whatever reason, once the oil started flowing under pressure it penetrated the interior of the rubber O-ring and began to erode away the rubber much like a river erodes its banks. The more surface area this erosion exposed the faster the rubber wore away until the seal was breached and oil could now flow out. With the metal mating surfaces not touching there was nothing to stop the pressurized oil from flowing out so once the leak began it increased rapidly and down went the oil pressure.
In this shot you can clearly see how bowed or arched this surface is. I have started to file the mating surfaces of these warped or bowed fittings to make them flat again. After a few passes over the file you can see the shiny outer ends of the fitting have been filed away because the middle area is still low.
I decided to flatten these fittings by hand with a file rather than milling them as I needed to get these surfaces completely flat so they would mate and seal perfectly when bolted to their Main Bearing Caps but I wanted to remove as little metal as possible so as keep the pressure on the O-rings when these are bolted down, to be the same as new.
Here is the fully flattened fitting on the Left while the Right one is just getting started.
All lube oil pipework fittings now perfectly flat and ready for another lifetime of fully sealed operation!
And call me paranoid if you prefer but I will refer to this as taking more of a “belt and suspenders” approach to ensuring these fittings stay completely sealed by using a bit of Ultra Black gasket maker on the outer surfaces for an additional seal. Probably unnecessary as the O-ring will do all the sealing now and the new batch of O-rings are not being split open when assembled, but doesn’t hurt to have this added sealant and additional peace of mind for me.
With the new crankshaft now back in place and the Main Bearing Caps all torqued down tight, it was easy to bolt on the now flat fittings and put the lube oil pipework back in place.
The whole bottom end has now been replaced with all new and some improved parts so time for one last double check.
At last I could carefully drag the 50kg/110lb cast AL sump back into the Engine Room, put on a layer of gasket maker on the outer flanges and lift it up onto the bottom of the crankcase.
I threaded some web straps underneath either end of the sump and ran them up to 6:1 blocks above the engine to lift the heavy sump up and line it up with the studs around the crankcase and then torque all 68 nuts down in stages.
Whew! A long time to get back to this point and now I just have to hope that I have indeed gotten to the bottom of this “murder” mystery and found and eliminated the serial Oil Pressure Killer.
I will leave it at that for this week and be back again next week as I put Mr. Gee back together and back to “bed” on his engine mounts. Now that I’ve had several practice runs I should be able to put him all back together fairly quickly and put those new seals to the test when Mr. Gee finally comes alive again and I can start putting on some hours and loads to confirm for sure that this latest mystery has been solved.
If you’ve made it this far, my congratulations for your perseverance and patience. Hope you enjoyed this murder mystery but as I said at the beginning, I’m looking forward to there just being ONE murder mystery author onboard Möbius, and I can go back to being her trusty crew.
Be sure to put any questions, comments or suggestions in the “Join the Discussion” box below and hope you will be back for more next week.
– Detective Wayne
Incredible story. Can’t wait for the next post. You are an amazing sleuth.
Thanks Sherry, glad you enjoyed the latest mystery story from this amateur author and I’ll do my best to keep more coming for you.
Congratulations on your patient sleuthing Wayne. I think that, in your situation, I would be far less phlegmatic and frantically pulling my hair out.
Here’s hoping this is the last time you ever need to look at your oil pressure gauge with anything but satisfaction.
– evan
Great sleuthing. We were wondering how Mr. Gee was doing. Fingers crossed.
Glad to have been able to satisfy your curiosity Rick. Stay tuned for the longer range verdict.
Well now that you mention it, my hair has seemed to thing a bit Evan! 😉
Appreciate the kind wishes and I definately share those same sentiments. Stay tuned to find out.
-Wayne
Well done, Mate! Let the world travels begin!
Thanks Kathleen. Need to get Möbius up an running properly for your upcoming visit right?
-Wayne
I always get bit by the assume and it can’t be.
“When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” ~ Arthur Conan Doyle
So how improbable is it that a casting has that warp?
Quite right John, as we have both found, that saying “Assume will make an Ass out of U and Me”! is so often so true.
ACD clearly understood all this which he so brilliantly used in crafting his characters and mysteries which have become classics.
No idea of the probability of this warping of those fittings but I have passed this all on to Michael and his team at Gardner Marine so they can be on the look out for it. As is often the case, once you know what you are looking for it is quite easy to see so it would only take mere seconds for someone rebuilding an engine to check for flatness of mating surfaces with a straightedge or the like and avoid the potential for similar failures of seals and such.
In the broader sense, this helps to remind me and sounds like many others following along here, of the need to be constantly aware of the assumptions we make all the time. I find that many assumptions slip by unnoticed as they tend to fly underneath our awareness radar so it does require quite a high degree of diligence and attention to catch yourself making these rather unconscious assumptions in daily life. Part of what makes life challenging and surely we would not want it any other way, though some days can be more challenging than others as I’ve recently been reminded.
-Wayne
Congratulations Hercule Poirot.
Your Orient Express is now back on track!
Funny, but I had a somewhat similar problem with some plumbing, where the gasket on the tap kept disintegrating every few months. Finally I refinished all the surfaces and the problem was fixed.
Way to go!
Rick
Hi Rick, glad you enjoyed this latest “novel” of mine and could put up with my amateurish attempts at writing. Must be particularly painful for English majors like you and Christine to put up with but I’m very happy you do!
Glad too that you’ve not got your leak fixed as well so onward and upward for us both.
-Wayne
PS. Hope your new hip continues to serve you well.
Awesome! What a discovery, here is trusting that all goes well from here on out.
Well done detective! Don’t keep us hanging there with Mr. Gee! You might need some mystery writing lessons to not let the tension staff on too long
Hey there Philip. No question that I’m in drastic need of more mystery writing lessons, and actually writing lessons of any kind but hopefully I won’t have too many more mysteries like this one to write about and I can leave all the mystery writing to the real author in the family!
-Wayne
Thanks Dave, great to have you along for the ride here.
Hope you and Joan have 2022 off to a great start and that one of these days our wakes will cross again.
Wayne
I’m sorry for your troubles w/Mr. Gee, but I really love hearing and seeing such a beautiful piece of machinery…and your words.
Thanks JZ, always good to know there are some fellow “gear heads” out there enjoying this journey with me. Not sure my wordsmithing is up to par with my mechanical work but glad to know that you are able to put up with it and still enjoy the journey.
-Wayne
Well done, I think you got it this time. You did the first rebuild while Mobius was being built in Antalya, right? The second rebuild occurred after your ill-fated run with the hired Captain. At that time, just before the second rebuild – did you closely examine the oil? Did you filter the oil through a fine metal screen? If you had, I wonder if you might have found little bits of rubber, as those o-rings eroded? Or maybe the debris was just too small?
Hi there Wade and Diane, hope all is well in Alanya and that we will get another chance to meet up before we head off.
You have the chronology of my multiple rebuilds of Mr. Gee about right. What I call Rebuild #1 was when I completely disassembled the original Gardner 6LXB after it had spent almost 50 years powering a tug boat plying the Thames in England. I finished that first rebuild about the end of 2020 and dropped it into Möbius for the first time just before we launched in Feb 2021. The ill fated first sea trial was in March last year and so I did the 2nd rebuild relatively quickly when we hauled out at the Antalya Setur marina in May. Then the oil pressure killer struck again on our trip up to Finike in July and so this latest rebuild I’ve just finished last week was #3.
You are quite astute in your questions about finding bits of rubber debris from the eroding O-rings as I did find some both in the oil filter which I did an autopsy on as well as finding more little bits of rubber in the grooves of the main bearing shells. I failed to mention this in last week’s story but you’re quite right that this did lead me to finding that it was those O-rings in the main bearing caps that were the source of the rubber bits. So I’ve known since I took Mr. Gee apart the last time back in August, that these O-rings were eroding badly and that they explained WHERE the oil pressure was escaping. But what proved more elusive was explaining WHY the O-rings were eroding away in the first place. As you now know it turns out that the surfaces of the cast iron fittings that the O-rings sat in were warped which left a gap for the O-rings to squeeze out into and be attacked by the oil flowing through. The final piece of the puzzle I finally fell into place when I found that the surface of the fittings was warped or bowed, and set up the “perfect storm” whereby the O-rings were being slit upon assembly as they rubber squeezed out into that gap and then once the pressurized oil started flowing it got under the little “flap” created by the rubber O-rings being sliced open and the erosion of the inner and slightly softer rubber began and accelerated till the seal was broken and now the oil could easily leak out the sides and the oil pressure began to drop. My speculative guess is that this erosion accelerated as more and more rubber was exposed and as more oil flowed out past them so that the pressure continued to drop more and more as a result. Discovering the bowed surfaces of the fittings was the Eureka! moment when all my Why? What? Where? and How? questions were answered and all the evidence I had matched up and explained what had happended and why the previous rebuilds had the same problem yet the oil pressure in the original engine had been fine for 50 years.
I’m still a bit “cautiously optimistic” as I won’t really know for sure until later this year when I’ve got 100 hours or so on the engine, but I’m feeling the best I have since this mystery began almost a year ago, that I’ve found the true source of the problem and fixed it for sure.
Stay tuned here as those hours of run time add up and we will all know for sure if I’ve got this mystery solved for sure.
Maybe we’ll need to take Möbius for a run over to see you In Alanya before we leave to log some of those hours?
-Wayne
I must say that I was gripped by this post. Your sleuthing was so exciting. Did you managed to ascertain why those cast iron fittings were not flat? Surely Mr Gee can’t be the only engine to suffer from bent fittings?
Hi Piers, thanks for the positive review of my latest mystery story. I have similar questions as to yours but I don’t know if there is any way of telling just why or what would have caused those cast iron fittings to warp. My only guess right now is that perhaps with the original O-rings being in place for almost 50 years, the constant pressure of the compressed O-rings had caused the cast iron to take a “set” where they were bowed out between the two hold down bolts. I’m in touch with Gardner in England about all this to make them aware of what I’ve found so hopefully I can help prevent other Gardner rebuilds from suffering this same problem. Checking the surfaces to be sure they are flat only takes a few seconds with a good straight edge so easy enough to check but I’m not sure that every mechanic would think to do so. It is easy to “assume” that “of course” a fully machined metal surface will always be flat and the original engine had good oil pressure for all its life so there was no reason for doubt. But as I’ve mentioned in several other posts and answers here, assumptions will tend to bite you in the @ss and we have to always be on the look out for the assumptions we make so easily.
Glad you’re enjoying the mystery so far and hope I don’t have too many more to share with you!
-Wayne
Wayne,
Look like Chris’ profession had rubbed off on you a bit. I read the first half of this email late at night and was very sleepy. BUT, today sat down in my recliner and was transfixed. I was not going to put this down until you found the problem.
Not only did you, but not only did you solve it, but you repaired it with no assist.
Congratulations “Sherlock”!!!
I was a helicopter mechanic in the Marine Corps and had some really tough mechical mysteries to solve a few times: engines, hydraulics, tansmissions, etc. Luckily I did not have one quite as complicated as yours and we always had assistance of the experts in our squadron.
Again, “Well Done” !!!
Fair Winds and Following Seas…
Jake
Thanks for the chuckle Jake that you would have found my amateurish authoring to be so captivating. There’s an hour of your life you won’t get back!!! 😉
I’m sure you are being far to humble about your mechanical repair experience and many of the challenges you faced in the MC would have been complex indeed. This latest challenge for me was at the other end of the spectrum in that the whole lubrication system on a Gardner LXB engine is so incredibly simple and straight forward. Yet here was this basic problem of oil pressure dropping which had to be due to oil leaking out somewhere and I could not for the longest time figure out where, why, how? I found the eroded O-rings fairly quickly so I knew that this was clearly WHERE the oil was leaking out, but I could not figure out for the longest time WHY were these O-rings being eroded away in the first place?
Then when I could replicate on my workbench experiments that the O-rings were being deformed and split open just by assembling them, I was at a loss for some time to explain why that was happening and what was causing it. Finally discovering that those cast iron fittings had warped and created a gap in the middle was the Eureka! moment when all the questions were answered and all the evidence and clues fit. But it did take me a good while to think to check the flatness and fit of those two metal mating surfaces to finally uncover the true oil pressure “killer”. Anyway, feels good to know what I’ve found the root source of the problem and been able to definitavely fix it so now I just need to get Mr. Gee all back up and running to put on some engine hours and know for sure it is fully fixed and set to run well for the next few decades.
Stay tuned and you’ll find out along with me and whatever the next mystery is lurking onboard.
-Wayne
I have been waiting for the conclusion to this story for some time! What a long and winding investigation. Gardner engines are some of my absolute favorite mechanical devices in the world, and this proves that even more. On a traditional engine, you would be hard pressed to have so much good access, diagrams, and ability to see the critical portions of the engine.
Such a tiny, inexpensive part, and such a strange set of circumstances that caused the problem. I think I’ve said that about a lot of things I’ve worked on over my life, and it tends to be something tiny that causes such amazing challenges, damage, or frustration.
Not that you needed it, but now you have several rebuilds worth of experience on this particular engine under your belt. I suppose you can say she’s been rebuilt twice now, and is brand new again hah!
And I bet you’ll be keeping a lot of sets of those o-rings, and the old damaged ones (or at least one from each rebuild) so you can compare over time. Maybe take them and frame them in a nice picture frame and hang them in the engine room as a reminder of fond times rebuilding.
Glad you solved the mystery!
Such a treat to get this note from you Steve and all the more so given how busy you must be enjoying your new boat “Kaos” and the very ambitious list of improvements you already have, so thanks.
It was indeed a long and winding investigation to track down the root cause of the loss of oil pressure on Mr. Gee and of course being brevity challenged I also made it very long winded! But I really do appreciate that you and so many others seemed to enjoy coming along for the ride with each new episode as I tracked down the true serial oil pressure killer, so thanks for that as well.
I’ve actually now rebuild Mr. Gee THREE times so he is brand new again, again and I have my fingers crossed that this will be his last rebuild for the next 50 years as well. Christine quite liked your fun idea about framing those tell tale O-rings from the previous rebuilds so I may just take that one and put them in a frame to display in Mr. Gee’s Engine Room. Those O-rings were also an interesting example of a situation I’m sure you’ve run into frequently as well where they were the source of the problem, where the oil leak was happening in this case, but NOT the cause of the problem. It was this question of WHY were these O-rings being eroded away and then leaking which I kept coming back to and which eluded me for so long. As you and other boat owners will relate to, I just could NOT continue by doing yet another rebuild and “just” put in new O-rings because I knew that I had still not found the root problem that was causing these O-rings to squeeze out and be damaged just by installing them on my workbench so I kept up the investigation until I finally found those warped or bowed surfaces on the cast iron fittings. While I still wont’ know for sure that I’ve fixed the problem until I have the first 100 or so hours on the “new again” Mr. Gee, I am feeling very confident that I have indeed found the true “killer” and gotten rid of him once and for all.
By the time I get Möbius anchored beside Kaos we will know for sure and I can’t wait for that celebratory drink with you, your partner and Christine as we toast Mr. Gee down in the ER in one of the PNW’s beautiful bays. We hope to finally cut the dock lines and head out to sea gain finally around April this year and our long range goal is to make our way over to your neck of the woods so early warning to you and others there that the good ship Möbius will be paying you a visit in the next year or two.
Thanks again for your kind words and taking the time to follow along Steve. Always really enjoy and learn much from your thorough and thoughtful articles on Seabits and keeping up with your adventures on Kaos and look forward to being able to meet up in person and share some time with you as soon as we get over to the PNW.
-Wayne
Hi Wayne,
you have succeeded in creating a real engineering masterpiece. I am very happy for you that you made Mr fit again. Congratulations!!!
Maybe I over read something, but I think about what caused the cast iron-blocks to bend? The damaged o-rings, looks like at the outside radius, a minimal amount of the rubber rings were squeezed between the metal surfaces. This could be an indication that the o-rings are too large.
Or perhaps the rings are also made of rubber that is too hard and the rubber creates a large resistance during assembly, so that the blocks bend?
Probably both assumptions are nonsense, because they were original spare parts. If the oil pressure is the reason for the bending of the blocks, many engines of this series would have this problem.
Again, compliments and thanks for letting us share, Benjamin
Hi Benjamin, thanks for the kind words and I’m glad you have been finding the blog to be worthwhile to read.
In the beginning, I noted the same characteristics of how the rubber O-rings were being squeezed out around their inner and outer ID I had similar thoughts as yours that there was something wrong with the O-rings themselves, either a bad batch of rubber or they were out of spec and too big. However Michael at Gardner very kindly got in touch with the manufacturer and confirmed that there had been no change in the rubber and that all the O-rings were well within their tolerances. That then left me still unable to explain what was causing the “squeeze out” to occur and it remained a mystery until I realized that the surface of the cast iron fittings which the O-rings fit into, were bowed in the center and left a gap even when fully tightened down. Once I flattened those surfaces and eliminated this gap, when I did some tests on the workbench by installing new O-rings and fully torquing down the fittings to the Bridges, they no longer were able to squeeze out and so they were in perfect condition when I removed them after being in place overnight.
As to what caused the fittings to warp or bend I don’t think Oil pressure itself would have been any factor and instead my best guess is that it was an artifact of them being in place for about 50 years with the constant pressure of compressing the O-rings. When new the O-rings are considerably “proud” of the surface so there is a lot of compression of the rubber which of course is by design to ensure a super good seal, and so there is considerable force being exerted on the middle area of the fitting between the two hold down bolts and my guess is that over such an extended period of time that they were in place in the original engine, some of this energy was able to slightly bend the fittings. As long as the O-rings stayed in place and the fittings were not removed then all was well and they stayed pressure tight with no leaks. When I removed the original O-rings from the engine when I received it they were still in very good condition, no splitting or erosion at all. However what I did not notice at the time was that the fittings themselves had taken a bit of “set” and were bowed out in the middle area and when I did not remove this in the first 2 rebuilds, some of the rubber on the O-rings was able to squeeze out into the gap and then as the fittings were torqued down, the rubber was pinched between the two metal surfaces which sliced it open and allowed the pressurized oil when running to lift up the little “flap” created by the split and start eroding the slightly softer rubber underneath the surface. As I outlined in the blog article, I was able to replicate this squeeze out and splitting in my workbench tests as well as see the resultant erosion very vividly as you saw in the photos after it had run for a few hours.
Perhaps unjustly so, but I’m quite confident that the root of the problem causing the loss of oil pressure was this gap created by the bowed fitting surfaces and now the new O-rings will work as well as always. I confirmed in my workbench tests that the O-rings were not being squeezed out or damaged so this seems like relatively definitive proof and I’m anxiously awaiting full confirmation once I get Mr. Gee running again and can take Möbius out for some extended sea trials. Stay tuned!
-Wayne
Morning Wayne
i really enjoy reading your project stories, we are building a 52 ft liveaboard trawler too powered by a 6lxb.. the old gardner is in bits at present and after reading through your murder mystery i will be heading out to the boat shed, digging out and checking those parts to see if they are flat! along with the oil tubes in the crank. your articles have been a great encouragement for us – thank you very very much
Brad & Sapi
Morning Brad, so rewarding for me to learn that the energy we put into writing and maintaining the Möbius.World blog are of value to people such as yourself who are off on their own boat building adventures. All the more so ones involving a Gardner! We have been fortunate to spend a reasonable amount of time cruising down in your gorgeous country and as you know that’s where Dennis and Artnautica are based so we hope to get Möbius there at some point on our upcoming passages. Highly likely as we have spent so many years cruising the whole SW Pacific region in our past time on sailboats.
Are you going to be rebuilding your 6LXB or will you have a shop down their do the work? As you likely know there are still LOTS of LXB’s in workboats especially down there in NZ and pretty much all over the world so finding people familiar with them is not usually too difficult after a bit of searching and asking around. In any case, please don’t hesitate to let me know if there is ever anything I can do to help you with the rebuild of your 6LXB.
I suspect that the bowing of the cast iron lube oil fittings on the crankshaft bridges that plagued our poor Mr. Gee is somewhat unusual and most likely the result of the original engine having had them in place for 50 years so perhaps them taking a bit of a “set” and being permanently bowed out in the center is not too much of a surprise. Fortunately this is very easy to both test and fix and you now know how. Any good straightedge held against the surface of those cast iron fittings will quickly tell you if yours are at all bowed out and you can further verify by running a sharp file over these surfaces when clamped in a vice. I’d recommend that you do this even if they do look to be flat as this will doubly ensure that they are completely flat and provide a brand new surface to seal against the surface. You would not be taking off any appreciable amount of metal, just cleaning up the surfaces so no harm done. I was able to both flatten and renew the surfaces on my fittings quite quickly just using a hand file as you saw in the photos. I found it best to clamp the file in a milling machine vise and hold the fittings in my hand rather than the other way around as I could keep the fittings very flat and solidly pressed against the file whereas a hand held file is easy to bow as you press down on it when handheld.
The oil tubes inside the crankshaft are also relatively easy to inspect with a good flashlight and perhaps the aid of photos with your phone to peer deep inside the large lightening holes where they sit. Be sure to run a good cylindrical bristle brush with cleaning solvent through all those oil tubes before you reassemble to be sure they are all scrupulously clean. I also found that I had to spend a good bit of time with rags and cleaning solvent (diesel or acetone) to remove all the dirty oil deposits that were caked onto the inside diameter of all those lightening holes in the crank so be sure that gets done as well so that none of this breaks away inside the newly rebuilt engine as it is running. I find that spray on Brake Cleaner does a very good job for the final clean up of such parts as it is extremely aggressive at removing every last bit of oil, grease and dirt before you give it all one last shot of compressed air to get the crankshaft squeeky clean before final assembly.
Hope this all helps and best wishes with your rebuild and new boat.
-Wayne
PS. If you have a blog or other links to any photos of your boat project and rebuilding of your 6LXB please do pass them on so we can see them.
Hi Wayne, thanks very much for your reply… i just seen it! – been in the boat shed for the past few weeks… i did go out to the boat shed to check the parts… all ok so far, but will be giving them a good once over when the time arrives, rebuilding the gardner – yes it will be completely rebuilt by ones self and help from a friend – my motto is “if i can not fix it, it does not come on the boat” plus i have a bit of a Gardner fetish – dont tell the wife, i have 3 6lxb and only need 1 haha.. always good for parts and choosing the best bits needed.
regarding a blog etc we are recording the build as we go (or when i remember!) with a possible idea of doing you tube page in a year or two.. at present we just want to build the boat – it has been in the making since 2008, and we sold everything in 2019 to start the project and work on it full time when possible…. slowly but surly. se i will organise some pics and send them to you soon
cheers
Brad
No problem Brad, busy times for all of us and glad to get this update from you. Look forward to seeing and learning more as your progress continues.
-Wayne