Help Diagnosing Oil leak

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donjetman

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Judging from your old valve cover, you have a lot of engine blow by either past the rings or valve seals. Or simply a plugged PCV hose. Should look sort of golden inside. Below picture is an LS 6.0 at 120,000 miles, oil changes every 4,000 miles.

View attachment 445948

Had another set of heads on the shelf ready to go, and since I was pulling these off to change minor head gasket leak.... Put the other set of heads on with updated valve covers
View attachment 445949
View attachment 445950
That's a gen 3, not the issue us gen4 owners have.
gm shafted us 2007 to 2011 gen4 owners by selling us vehicles with a defective pcv system, see this TSB: https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf
 

donjetman

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View attachment 445940

Received the new valve cover and gasket yesterday. I went ahead and changed the oil last night and installed the new valve cover.

Time to put some miles on the truck I'll report back.
WOW. :doh2: Thats worse lookin than mine was :banghead:.
I added a catch can first and was catching 1 oz of oil every 100 miles. After the ds vc change and combustion chamber/piston soak it dropped to next to nothing, and remains that way still.
Be very careful if you use any product(s)/oil(s) to clean it up. If something breaks free it may plug-up an oil passage, the dog bone, a bypass, etc, etc.
HPL sells a 30w oil specially designed to desolve the crud. Multiple frequent oil filter changes are a must.
https://www.advlubrication.com/products/engine-cleaner
Yukon VCs.JPG
Catch can.JPG
 

rdezs

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It's possible the rings are just gummed up. That solvent stuff you had to the oil makes me nervous though. I've seen some LS oil pumps suddenly lose pressure.... And found little tiny pieces of grit in the pressure relief valve. It would also make me nervous if any little pieces made their way to a lifter. The filter should catch it, but then again on a cold start with high oil pressure, some oil bypasses the filter through the oil filter pressure relief valve above the oil filter on some, and built into the oil filter on others. I can't remember what you said your mileage was. If it's around 200,000 miles, it's probably a little bit of everything. (Rings, valve guides and valve seals)
 

rdezs

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Yes, that picture of the inside of my head is a generation 3..... With a lousy PCV system that I upgraded to the newer 6.2 style valve cover. The old one actually used a PCV valve.... Looks like it had been doing its job properly though.
 

j91z28d1

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Yes, that picture of the inside of my head is a generation 3..... With a lousy PCV system that I upgraded to the newer 6.2 style valve cover. The old one actually used a PCV valve.... Looks like it had been doing its job properly though.


I believe the pvc valve was a good design for years. even the only ls sports cars didn't start drinking tons of oil till they did away with it. even moving to the lifter valley from the valve cover didn't fix it completely.

catch can the world haha
 

j91z28d1

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It's possible the rings are just gummed up. That solvent stuff you had to the oil makes me nervous though. I've seen some LS oil pumps suddenly lose pressure.... And found little tiny pieces of grit in the pressure relief valve. It would also make me nervous if any little pieces made their way to a lifter. The filter should catch it, but then again on a cold start with high oil pressure, some oil bypasses the filter through the oil filter pressure relief valve above the oil filter on some, and built into the oil filter on others. I can't remember what you said your mileage was. If it's around 200,000 miles, it's probably a little bit of everything. (Rings, valve guides and valve seals)


I think the way he did it by soaking the rings shouldn't increase the risk of running gunk thru the oil pump as much as the oil stuff.
 
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lspann3525

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It's possible the rings are just gummed up. That solvent stuff you had to the oil makes me nervous though. I've seen some LS oil pumps suddenly lose pressure.... And found little tiny pieces of grit in the pressure relief valve. It would also make me nervous if any little pieces made their way to a lifter. The filter should catch it, but then again on a cold start with high oil pressure, some oil bypasses the filter through the oil filter pressure relief valve above the oil filter on some, and built into the oil filter on others. I can't remember what you said your mileage was. If it's around 200,000 miles, it's probably a little bit of everything. (Rings, valve guides and valve seals)
Yep im at 275xxx.
 
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lspann3525

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Do yall think marvel mystery oil would help any??

Next time I change plugs i'll try the piston cleaning procedure
 

mikez71

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I thought MMO was what they used back in the day for stuff like this? (I never did so no experience here)
 

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