2024 Silverado 2.7l rear main leak

[Tmh350]

I Bought a 2024 left over Chevy 1500 custom about 2 months ago, with the 2.7l it had 23 miles on it. 3 days after taking ownership noticed a oil leak with around 200 miles on it. Brought it in to the dealer, turns out rear main was leaking witch I already new from looking around underneath. Took the dealer about a week to get the parts and two days to complete the work. The day after getting it back it’s leaking worse than before. Bring it back to the dealer, they do the job again, they test drive it still leaking. Now there’s a case open with GM there on the forth time of doing the job, spoke with the service manager yesterday and I really have no clue what there next step is going to be. Long story short I know a lot of these 2.7 have crank seal issues but was wondering if any one else has had experience with the job being done e this many times,and still not fixed, and if so what was the final outcome. At this point the dealer has had the truck more time than me. It’s been the worse vehicle purchasing experience ever.

[silveradosid]

it could be a bad tech but i am sure they would be double checking thing after the second failure. i would guess that the pvc system has a problem and it is causing the seal to fail. the pvc system on this engine is junk, i have had a problem with mine 

[PunchT37]

Is it really the rear main seal?

[silveradosid]

good point Punch, when the fine oil separator failed on mine it leaked oil down the back and dripped off the bell housing

[Tmh350]

I got it back Thursday night, the dealer put almost 200 miles on it, and I’ve put about 300 on it. So far no leak I don’t have faith but fingers crossed. They did a crank pressure test said it was in spec. I asked about the pcv system they said it checks out what ever that means. A GM rep did come to the dealer, if it leaks again they said they will do a short block. I do not want that, the truck will never be right again.

[Tmh350]

On 6/28/2025 at 1:38 PM, PunchT37 said:

Is it really the rear main seal?

Yea you could see it plain has day where it was seeping out off.

[PunchT37]

3 seals leaking? Either bad luck on parts, a BS tech, or a misdiagnosis. 

 

Which means BS tech. OR, the crank has a bad spot or roughness eating the seal. Then, refer back to earlier statement.

Edited June 29, 2025 by PunchT37

[TrueBlue]

In June of '23 I bought a new '23 LT with the 2.7L in it. After about 700 miles I noticed what I believed to be a rear main leak. I had already decided I should have waited on a 5.3 like I originally wanted so I traded that 2.7 in and got my 5.3. This gen of trucks was so new then I had no way of knowing that it could have been a recurring problem like you had. I hope they fixed the root cause of yours and you have no further issues.