Yukon 2022 6.2 engine died at 75,000 miles.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

BacDoc

Full Access Member
Joined
Apr 11, 2024
Posts
449
Reaction score
542
Location
Vero Beach Florida
This is very cool and interesting information. I probably didn't write it in detail. We did not increase the gaps between the liners and connecting rods. We have just reduced these gaps by installing L86 liners instead of L87 liners. Because the L86 earbuds fit more tightly. We sharpened the gaps inside the cylinder, increasing them between the cylinder wall and the piston. The main problem was precisely in this place. The piston inside the cylinder on the new engine did not move freely, it wedged a bit. this caused scratches and scuff marks on the cylinder walls and the Teflon coating of the piston.So we didn't do anything new, we just adjusted the temperature gaps inside the cylinder according to the GM documentation.
This is essentially blueprinting!
 

West 1

Full Access Member
Joined
Jan 20, 2023
Posts
169
Reaction score
261
When building engines with tight clearances it is necessary to have all the parts and block at the same temperature. If the pistons are 80* and you are putting them in a block at 50* you will have issues with size and fit. Common issue in engine building. Performance builders will leave the block and parts overnight to acclimate to the same temps before assembly to avoid issues.
 
OP
OP
Vladimir2306

Vladimir2306

Full Access Member
Joined
May 18, 2023
Posts
800
Reaction score
891
When building engines with tight clearances it is necessary to have all the parts and block at the same temperature. If the pistons are 80* and you are putting them in a block at 50* you will have issues with size and fit. Common issue in engine building. Performance builders will leave the block and parts overnight to acclimate to the same temps before assembly to avoid issues.
So it is understandable, the block and the pistons are in the same room
 

cornicekurt

Member
Joined
Mar 23, 2025
Posts
73
Reaction score
50
Glad you have your rig back running again. Very impressed that you have such good mechanics available and got the work done so quickly.

Couple notes, sorry I just found this post today. I worked for Federal Mogul for 30 years, for much of that time I worked as an Automotive Engine specialist and the final 7 years as a Diesel engine specialist. If you don't know for most of that 30 years Federal Mogul provided about 70% of GMs engine bearings. Bearing failures were designed out 30 years ago. It appalls me that GM is now having Engine Bearing failures. I left the company in 2019 when Federal Mogul was bought out by Tenneco. Up to 2019 they were providing very high quality engine bearings to most of the OEM engines built. Clevite also provided many OEM bearings but not as much as FM did. To avoid bearing shortages durring production GM and all manufacturers had back up suppliers for every part. Usually one primary supplier and 2 back ups. This allowed supply even when one company had issues.

IF GM bearings are spinning in the connecting rod do we know if the bearing fails and then spins? Or does it spin and then fail? If it spins first the rod bearing does not have enough Crush built in. Crush holds the bearing in place, the little tangs are just there for assembly alignment they do not hold anything. Once torqued in place the rod bearings are crushed into place and will not move for the life of the bearing. Properly installed the bearing can be removed even after 200,000 miles use and when you look at the back of the bearing you can still read the stamped part number, date code and size on the back of the bearing, you can also see the cross hatch that was on the connecting rod where the bearing was mounted. This is true because the bearing was clamped in place with enough crush to imprint the cross hatch into the back of the bearings. They did not move as they should not. It would be interesting for me to look at some of these failed bearings to study them.

In the photos I saw pictures of bearings taken from the new engine block you purchased. They do not look bad to me. Yes you can see minor scratches but you need to know the scratches look like they are only in the Tin Plate. Tin plate is used on bearings for two reasons. 1. It helps protect the bearings from aging while on the shelf. 2. In a minor way it helps lubricate the bearings on install for start up. Tin plate is only a few Millionths of an inch thick. You can scratch it with a finger nail so any contact in a rotating engine will leave marks. The marks look bad but they are nothing to worry about. Feel them with a finger nail, if you can't feel it don't worry about it. In the US Tin plated bearings were being phased out due to environmental laws. Copper Lead and Tin are all endangered materials and are being banned to help clean the environment. I suspect the tin plated bearings were made outside the USA.

The latest bearing technology I was aware of was high silicon Aluminum bearings, aluminum mounted on a Steel back, the high silicon bearings were Bored to size so the surface looked similar to an old style record with grooves covering the face of the bearing. Very fine groves. These bearings were so good they were going 300,000 miles with near zero wear and the crankshaft in those engines looked brand new after the long 300,000 miles of use. They were not a failure item and were better than any bearing ever installed.

They did have a Horsepower limit, back around 2000 that limit was considered to be 500 HP. The first bearings were A500 material, later generations A600 had a much higher horsepower ability but as those were coming out I was leaving the company.

The coated bearings were being used by racers back then, coatings were known to allow very short term contact with the crankshaft without damage. Bearings should never touch the crank, they are normally separated by an oil film but in extreme situations they can touch and the coatings let them live with no damage in that situation.

At the OEM level oil clearances for Rods and Main Bearings were getting tighter and tighter. Smaller clearances reduced NVH. Noise, Vibration and Harmonics in the engine. Plus tight clearances led to longer engine life. Toyota had been running Rods and Mains as tight as .0012 to .0015 as far back as 2005. This is not new technology, it is the norm. Most US manufacturers stick to clearances around .002 rods and mains.

If your shop increased the clearances inside your rebuilt engine I would not even consider running your 0-20W as it would leak like a sieve when hot.

One thing I did not see discussed when you mentioned your oil choice was the Temperatures your engines run in. I bet in Moscow you see very cold winters. In extreme colds you are Forced to run thinner oils. The oil can be so thick on cold starts that you can do engine damage if it is not thin enough to flow on start up. In the USA we might have some spots, maybe North Dakota in mid winter where guys would be aware of this same issue? A lot changes and needs to be adapted to in extreme cold.

If you increase Rod and Main clearances the only thing you do is spill more oil as the engine runs. Rod bearings spill oil that lubricates the cylinder walls and pistons when running, this is throw off oil. IF you increase rod clearance from .002 to .003 or .0035 the amount of oil on your cylinder walls increases by far more than double. This can lead to the currently light tension piston rings being overwhelmed and create and engine that burns oil. It also lowers your idle oil pressure because the pump does not put out enough oil to keep the system at full pressure at idle. Most any shop will recommend .002 for rod and main clearances today. The factory runs a little tighter.

Federal Mogul has sold three times in the past 6 years so I have no idea if quality has survived or even if they still build the bearings in the USA, last I was aware they had 2 plants in Michigan building bearings but they were also building in other parts of the world.

On the Diesel side of the business there were some very popular Engine bearings that were only being built in China as of 2019. These were for Cummins, Detroit and Caterpillar and those users were not happy at the time but we had no other options so knowing this I bet automotive engine bearings have also migrated to China or other countries.

You mentioned you might have overheated your engine causing the bearing failures? I don't think so, in overheated engine blocks we saw failures of the Pistons, the oil would burn to the hot cylinder wall and the pistons would scuff the skirts. The bearings were usually fine with no damage most times in overheat situations. Older engines would have head gasket failures but the new Multi Layer Steel Head gaskets are really tough and most times will not fail even in overheat. The LS design engines run MLS head gaskets.

One picture showed that the crankshaft had been moving forward or back and rubbing. That would tell you the thrust bearing had failed. For it to fail again I am suspecting you had an oil supply issue. Oil pumps do not fail while running along at 2700 RPM, something disrupted the supply of oil getting to the pump or blocked the oil gallery where the pump was trying to feed the engine.

I think you had an oil supply issue. Backed up by the heat marking on the Rods and crank. The oil pick up tube oring is usually the most common fail in the LS engines.

Sorry to be so wordy but helping with engine failures is what I did for at least 20 years. I did not work with the OEM customers I called on large rebuilders that built as many as 2000 engines per month. Got lots of feedback if things did not work. I did work a lot with the guys that called on GM, Ford, Chrysler, Mercedes, etc. Learned a lot from those guys.
What do you suggest we do with these vehicles that are on the recall list? Anything? Independent inspections? Independent oil analysis? Or would you just trust that the dealerships are going to do right by us owners?
 

West 1

Full Access Member
Joined
Jan 20, 2023
Posts
169
Reaction score
261
If it really is just a bearing issue do we know if it is Mains or Rods failing first? Once one bearing fails the particles ruin the rest of the engine so you need to know what happens first. If it is really a rod bearing issue I would drop the pan and change them out to either Clevite, Federal Mogul, ACL or maybe even King Bearings. Clevite and Fm have been providing OEM engine bearings so I trust them most. ACL next and King Last. I would not run other brands. I have been out of the business since 2019 so I would need to do some study to see what bearings failed and whose bearings are still working.

I have not tried to change main bearings in a car with the LS engine design. It might be possible but I can't say.
 
OP
OP
Vladimir2306

Vladimir2306

Full Access Member
Joined
May 18, 2023
Posts
800
Reaction score
891
Hello everyone. Who is following my story :) And so in a week I drove about 700 miles, following all the recommendations of the service, about the running-in mode. During the run-in, Mobile 0-40 oil was poured. What I immediately noticed was the high pressure, which was clearly higher than what I had on my previous engine. We have a metric measurement system. If the full scale is 800 kPa, then the middle scale is 400 kPa. So, in my opinion, the oil pressure on the new engine is about 250-270 kPa.
 

Attachments

  • 2025-05-26 20-37-23.JPG
    2025-05-26 20-37-23.JPG
    153.6 KB · Views: 8
OP
OP
Vladimir2306

Vladimir2306

Full Access Member
Joined
May 18, 2023
Posts
800
Reaction score
891
Next, I started looking for my old dashboard photos, where the oil pressure scale is visible. Here, on a run of 74 thousand miles, it would seem much lower than my current pressure, in my opinion it is about 160-170 kPa, and I found a photo from a run of about 5.5 thousand miles, the pressure there is the same as on 74 thousand miles. I asked the service, they confirmed that this is a normal pressure at idle and the engine is warmed up, about 170 kPa.
 

Attachments

  • 0Ftxnj39K1aB3rO0NR4j6LeWnZw-1920.jpg
    0Ftxnj39K1aB3rO0NR4j6LeWnZw-1920.jpg
    205.6 KB · Views: 7
  • Z6AeCaBtiShcH3zo3EQocnJnsVM-1920.jpg
    Z6AeCaBtiShcH3zo3EQocnJnsVM-1920.jpg
    177.1 KB · Views: 7
OP
OP
Vladimir2306

Vladimir2306

Full Access Member
Joined
May 18, 2023
Posts
800
Reaction score
891
I drove 700 miles on 0-40 oil during the run-in, after which I filled 0-20. It seems that the version that it is necessary to pour oil 0-40 is confirmed, at 0-40 the pressure is high, and at 0-20 it is about twice as low. Do the photos confirm this? :) But no, fans of this movie, :) it's not that simple) after running in, I filled in exactly the same oil that I used to drive 75,000 miles on my previous engine, this is the oil from the Belgian company Wolf 0-20 dexos. Why did I fill in 0-20 anyway? I talked to the Service that made this engine for me. Everyone they made an engine for runs on 0-20 oil, and the mileage on the new engine is already high. So, they poured 0-20 oil on me, I rode a little, warmed up, drove along a small section of the highway at a speed of 70-80 miles per hour, and that's what my oil pressure is 0-20. Wonders. it is about 300 kPa. I'll even post a photo of the oil pressure 0-40 and 0-20 next to it))) at 0-20 it's just a little lower. well, about 300 kPa at 0-20 and maybe 320 kPa at 0-40. My opinion is that either the software has changed and GM has increased the oil pressure, or this is a new modification of the oil pump. But oil has practically no effect on pressure. The pressure on my new engine is clearly higher than on the previous one.
 

Attachments

  • 2025-05-26 19-34-31.JPG
    2025-05-26 19-34-31.JPG
    187 KB · Views: 12
  • 2025-05-26 20-37-23.JPG
    2025-05-26 20-37-23.JPG
    153.6 KB · Views: 11
Last edited:

Forum statistics

Threads
135,561
Posts
1,923,405
Members
100,695
Latest member
zoongizi
Top