In regard to the EGR cooler. I remember some company was making an improved version? Maybe that was for the older ones? I think the coolent has a lot to do with it which Is why I went to the best Zerex HD ET Diesel. Did 10 Gallons of flushing.
Amsoil makes a coolant additive that can in some cases especially with engines that use a water mixed coolant lower temp up to 10 degrees.
I'm using that one. At first I used Redline Water Wetter and it was not compatible with our coolant. Maybe that is why they make one that says Diesel? Anyhow i did 10 gallons flush with the Zerex so im good now and cleaned out all of it.
How do we know the percentages of those that are under, or over, that mark?
BulletProof Diesel makes a high quality EGR cooler
Most EGR coolers fail due to either metal fatigue or the cooler clogging with soot/carbon. The BulletProof cooler is designed with larger passages that should reduce thermal stress and prolong soot buildup.
WAG.
It would be impossible to know the exact percentage. Even when calculating the engine failure rate (spun bearings), the best we could do was estimate a 10% - 12% failure rate. Stellantis conducts their own internal investigations which gives us some nationwide data. For example, Stellantis estimated less than a 1% failure rate on the CP4 pump. Stellantis also reported 215 spun bearings failures for a three-month period. It was pretty clear that build quality was the primary issue with the spun bearings.
So on thd spun bearing that is definitely quality control as lock to lock is the desired orientation of the bearing locks. Additionally each journal on that crank has to be basically precise measurement of the next. Unless it uses a stepped main bearing set up as does a few toyota motors. Where there is a marked increase as it goes from front to rear .
(mine failed)
We found that clearance was an issue. In some cases, we think the wrong bearing size was used. Also, the quality of the bimetal bearings were hit and miss. That's a conversation by itself. In short, there are three different size of main bearings that match the block, crank, and bed plates. As you alluded to, these engines require absolute precision. That's why some engines failed at 10,000 miles and other engines last 500,00 miles. The 2nd gen EcoDiesel earned its reputation for being a Hero or a Zero. Crank distortion isn't a problem if there's enough clearance, but we do see accelerated wear when the clearances are too tight.
Quality control is certainly an issue. One of the engine builders recently sent me this message: "I checked the clearance on that bottom end .002 on the mains and they mains had a decent amount of wear so was probably .0015 from the factory and all of the rod bearings where installed wrong."Turned out that Yamaha discovered that in the assembly plant workers were NOT applying assembly lube on the cams and etc. And a dry start condition was created from the get go making a scare that eventually ate the bottom of the lifter off.
Yes, the CP4 for sure is a lubricity issue. The rest of the failures can be related to not priming the pump when doing filter changes or actual fuel contamination (water, DEF, gasoline, etc.).
Why?
Factory, over the years, has used under-sized bearings where needed. Usually the block and cap are marked. One example is the marking of A, B or C. If it's A it gets a .001 undersize, B gets .0015 or 2 and so on.
To align them correctly in the cap. The 2 ends of tbe bearings after caps are put on push against one another which does the job of preventing rotation IF all clearances are per spec. I know it sure help when you have to do a fly by night bearing job. And the block is still in the truck . I literally have left the scene of a off roading rollover situation that resulted in damaged bearings. Bought bearrings . Dropped the oil pan. Loosened all caps . And gently slide the new ones in around that lip,tang , lock what ever it is lets ya know its in there correctly situated. So that tang has to line up with that notched area or something else bad will take place
The failure causes the coolant to mix with oil? I was thinking it had to due with acidity opening up weak points in the construction.
