Brand New GMC 3.0 with bad oil leak

[Sierra 3.0]

Sorry, I guess I misunderstood. Let's try oil cooler?

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[topgear1224]

Sorry, I guess I misunderstood. Let's try oil cooler?

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Oh that makes more sense. Leaking from drivers side?

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[Sierra 3.0]

Yes

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[Stephen Foster]

I found my leak on a 2021 on the drivers side thought the filter was loose tried tightening and then I realized the gasket/seal from the oil filter adapter to the engine block was leaking. Here’s a video of it. Also found a seal for the trans line installed incorrectly. 

 

[Wayne Black]

From what I understand there is a company in Flint, Michigan doing quality control checks on the raw 3.0L castings and they are scraping out a lot of faulty castings.

Something to do with the rear oil seal area.

These are raw castings from Mexico and haven't had the final machine work done.

My theory is, some faulty ones are getting through and the rear oil seal isn't sealing as it should after the final machining.

[Bmf007]

So guys have a 2020 at4 3.0l diesel and just went to drive it this morning and seen about 3 quarts

On the garage floor so pissed. Need to get it towed in to the dealer. Any ideas what's wrong only 7660. Just about over gm trucks

[BIGDOGx]

On 1/9/2021 at 11:46 AM, Bmf007 said:

So guys have a 2020 at4 3.0l diesel and just went to drive it this morning and seen about 3 quarts

On the garage floor so pissed. Need to get it towed in to the dealer. Any ideas what's wrong only 7660. Just about over gm trucks

Ouch that is a rough one, sorry to see you having trouble like this. 

 

Reading here it seems some blocks have defects with the machining of the block, not saying that's the issues but these engines have such a small sample size right now it will be tough to get much info on them outside of the dealer techs. That is part of the game these days, you are essentially a beta tester for gm, paying one at that, not saying they didn't do their due diligence in the engineering of this engine but teething & growing pains with the amount of crap that is put on these engines is bound to happen.

[DavidJ4545]

I was smelling a burning smell from the day I bought my 2020 GMC 1500 3.0L diesel. At about 5500 miles it blew the rear seal. Trucks been at the shop for almost 3 weeks getting repaired. Makes sense what the burning smell was now. Probably end up trading it in. 

[wadecool]

I wanted to add my experience to the above info.  I have a 2020 Silverado RST 3.0 Duramax with 11,000 miles.  I have had no issues since I bought it new until last week.  Truck went into limp mode and CEL came on.  Took to dealer and they found the rear main seal was leaking and are still working on it.  

My concern is that if the machining is faulty, won't the issue just happen again?  The dealer is going to fix the leak but I am sure that doesn't involve machining work does it?

[BIGDOGx]

On 2/22/2021 at 9:27 PM, wadecool said:

I wanted to add my experience to the above info.  I have a 2020 Silverado RST 3.0 Duramax with 11,000 miles.  I have had no issues since I bought it new until last week.  Truck went into limp mode and CEL came on.  Took to dealer and they found the rear main seal was leaking and are still working on it.  

My concern is that if the machining is faulty, won't the issue just happen again?  The dealer is going to fix the leak but I am sure that doesn't involve machining work does it?

Yes it will more then likely leak again if the block casting is faulty and they try and band aid fix it with another seal. I would fear some pile of you know what bulletin trying to force dealers to goop the seal and hope it holds. Much like the window issue on these trucks, dont fix the cause, just apply copious amounts of sealant to see if they can plug the leak.

Edited February 24, 2021 by BIGDOGx

[Dunn]

yeah they dont just hand out new replacement trucks like gumball machine......even at times when they should!.....just hope the issue is small and can be fixed without too much drama.....so far have been really lucky with new vehicles but never know....

 

if a new one had a huge issue i would have a kiniption fit that i do know...and wouldnt stop until i found the person who said "YES"

[AppFan]

A couple weeks ago my daughter told me my truck (2020 LM2, 7k miles) was "dripping" going down the driveway.  I figured she was talking AC condensation but got out and looked anyway. There was a trail of oil going down the street, the entire underside of the truck was coated and a puddle quickly formed underneath. I knew it was clean that morning as I washed it. No CEL yet but with no oil registering on the dipstick I threw a pan under it and called the dealer to pick it up. Got a call at the end of the day it was the rear main seal. Took about a week as the timing cover was on back order but the dealership was great to work with. Just glad it didn't happen a day earlier as we were away home home on vacation. 

[newdude]

Well, its not a block issue.  Its a rear timing cover issue.  GM says to replace the cover for a rear main oil leak  They also want the dealer to document the position of the seal in the old cover:

 

 

Quote

 

#PIP5795: LM2 Diesel with a Rear Main Oil Leak with or without DTC P06DD set - (Mar 30, 2021)

LM2 Diesel with a Rear Main Oil Leak with or without DTC P06DD set

---

Brand:	Model:	Model Year:		VIN:		Engine:	Transmission:
		from	to	from	to
Cadillac	Escalade Models	2021		All	All	3.0L (LM2)	All
Chevrolet	Silverado 1500	2020 - 2021		All	All	3.0L (LM2)	All
Chevrolet	Suburban	2021		All	All	3.0L (LM2)	All
Chevrolet	Tahoe	2021		All	All	3.0L (LM2)	All
GMC	Sierra 1500	2020 - 2021		All	All	3.0L (LM2)	All
GMC	Yukon Models	2021		All	All	3.0L(LM2)	All

 

Involved Region or Country	North America
Condition	A customer may have a concern with an oil leak. The technician may find DTC P06DD set.
Cause	The rear main oil seal may have moved or severely shifted out of position in the Timing Chain Lower Cover.

Correction

Replace the Timing Chain Lower Cover that comes with a seal already installed

Refer to Service Information for Timing Chain Lower Cover Installation Procedure.

If the seal is crooked or tilted out of position, use a caliper and record the depth where the seal is pushed in prior to removing the rear cover

Also place an indexing mark on the seal and cover in case the seal falls out or moves during shipping of the part to the Warranty Part Center (see picture below).

 

Record the Part Unique Number found on the white label attached to the back of the cover as shown in the picture below.

 

Example: PUN 50H32015310119

The Timing Chain Lower Cover comes with a 2 piece protector/installer. 

The inner piece becomes an installation tool. 

The outer piece simply holds them together for shipment.

Remove the outer piece (2) and discard it.

 

Note: The inner piece is an installation tool designed to be a substitute for the EN52466-2 installation tool. It fits over the bevel on the end of the crankshaft to facilitate installation.  Be extremely mindful that the inner lip of the seal slides over the rear of the crankshaft without rolling or a repeat oil leak will occur.  The protector/installer has a snug fit to the pilot of the crankshaft.

The picture below is shown without the cover for clarity.

 

Parts Information

Description	Part Number	Qty
Lower Timing Cover	55515618	1

 

 

Edited May 1, 2021 by newdude

[EB-RST3.0]

I can throw my hat in the ring on this issue. Mine dumped oil at 8300 miles 4 1/2 weeks ago. Truck was picked up via flatbed tow and has now been in shop for over a month. First diagnosis was to follow a TSB that said to replace timing cover gasket. It took 3 weeks for the parts to arrive and the same for a service loaner to be provided. Dealer installed parts and tested (I do thank them for their thoroughness) and found it is still leaking.

 

They do not know what to do next and they're awaiting instruction from GM. Meanwhile, I've now made two more payments on a truck that I do NOT have. Pretty bummed-out. 

[Glenn Blazek]

My experience of a major oil leak on the duramax 3.0L is just above the oil pan, squirting out of the oil cooler body. Oil only no coolant visible. I surmise a gasket failure but is in the dealer's hands for further evaluation. No oil on the dip, but maintained oil pressure while running it up in the tow truck. Engine with only 8K miles