Oil Leak 2019 Sierra Elevation 2.7l

newdude · April 13, 2023

On 4/10/2023 at 10:37 AM, BG1934 said:

UPDATE: Miraculously after repeated calls and emails to GMC the parts they were looking for showed up Friday..... I got a call on my way home from work. The service advisor tells me they installed the new alignments dowels with no issues. Upon start up and warm up there was no oil leak, They take it for a shakedown drive. When they got it back....there it was leaking oil again. 4 months of this crap. He tells me that they have a "team" (probably one guy with a laptop) of engineers coming to look at it Tuesday. He goes on to tell me that this is the first he has seen like this and only time he has seen something his mechanics could not repair. I spoke to the service manager and asked what happens if the "team" cant figure it out either. The service manager said most likely they will buy me out of the truck. My worry now is what does "buy me out" mean? I put $7500 down on this truck to get it where I wanted to be payment wise. Are they going to try to buy me out at trade in value and I am going to get screwed out of my down payment? I am hoping someone on here has some kind of experience with this sort of thing. I have none lol. Im just a project manager. I have no idea how to protect myself here. Maybe just get an attorney???

Makes me think the oil isn't coming from the rear main unless they botched installing that rear cover assembly.

BG1934 · April 13, 2023

2 hours ago, newdude said:

Makes me think the oil isn't coming from the rear main unless they botched installing that rear cover assembly.

I am of the same opinion. I have plenty of motors and repaired them regularly when I was racing. I have never seen an issue that even seasoned mechanics couldn't find. I am hoping they can remedy this because I really like the looks and amenities truck has.

BG1934 · April 25, 2023

UPDATE#2

The engineers looked at it. They deduced that the bolts for the cover that houses the rear main seal have worn out somehow. Their solution is to install some new bolts with rubber gasket material molded to them. Not sure if that is factory or some engineering thing taking place. They are waiting on the bolts now.........Why do I feel like this is a shot in the dark!!!!!

newdude · April 25, 2023

8 hours ago, BG1934 said:

UPDATE#2

The engineers looked at it. They deduced that the bolts for the cover that houses the rear main seal have worn out somehow. Their solution is to install some new bolts with rubber gasket material molded to them. Not sure if that is factory or some engineering thing taking place. They are waiting on the bolts now.........Why do I feel like this is a shot in the dark!!!!!

Oil leaking through a bolt hole is possible, but typically unlikely/rare. That would imply that the casting in where those are might be porous in which case, the only fix there is likely a long block.

I'm wondering too if the new rear cover leaked from improper RTV use on the cover, or if they didn't install the cover fast enough or let it cure. The stuff GM has dealers use now is made by Threebond, 1217H, GM number 19369831. It has an 8-10 minute working window to seat the piece back on to the engine but a skin over window of 5 minutes. There is also a special tool alignment pin set that is used to ensure the cover goes on straight.