L99 oil leak

[PlymouthBarracuda]

I am very sorry if similar discussion was before...

I have oil leak on my 2011 chevy camaro / auto trans. It appeared after using oil flush before oil drain, but maybe it is just a coincidence. It is neither transmission leak nor engine's back side gasket leak, I opened cap, it's dry and clean inside..

I suppose that it is the left head gasket :( I plan to replace it and grind the head of the block at the turner. Could anybody help to determine possible place of leakage ?

[InFiD3ViL]

Start with the valve cover and work your way down. Could be leaking from the valve cover gasket itself and also the cover's bolt O-ring seals. These cars are also known to have issues with leaky oil coolers, but your leak looks to be coming from a bit higher up.

I would say it is very unlikely the head gasket in my opinion.

[morepowerjoe]

+1

[dma05]

I was educated about head gaskets when I thought I was leaking oil from my head gasket. You pretty much can’t leak oil through our head gaskets as no pressurized oil passes through there. The only likely leak from a head gasket would be coolant.

This looks to me to be a valve cover gasket either from the main valve seal or from the grommets around the screws on the top of it. The valve cover gasket is an easy fix though.

[PlymouthBarracuda]

Originally Posted by InFiD3ViL

Start with the valve cover and work your way down. Could be leaking from the valve cover gasket itself and also the cover's bolt O-ring seals. These cars are also known to have issues with leaky oil coolers, but your leak looks to be coming from a bit higher up.

I would say it is very unlikely the head gasket in my opinion.

thank you very much. I can replace valve cover gasket by myself it's not a big deal ) and will monitor the issue in future. Oil cooler gasket with 4 holes also leaks ))

Per your opinion, could this additive reduce engine hesitation when AFM is enabled ?

[PlymouthBarracuda]

Originally Posted by dma05

I was educated about head gaskets when I thought I was leaking oil from my head gasket. You pretty much can’t leak oil through our head gaskets as no pressurized oil passes through there. The only likely leak from a head gasket would be coolant.

This looks to me to be a valve cover gasket either from the main valve seal or from the grommets around the screws on the top of it. The valve cover gasket is an easy fix though.

+1 thank you sir

[bertie]

Originally Posted by InFiD3ViL

Start with the valve cover and work your way down. Could be leaking from the valve cover gasket itself and also the cover's bolt O-ring seals. These cars are also known to have issues with leaky oil coolers, but your leak looks to be coming from a bit higher up.

I would say it is very unlikely the head gasket in my opinion.

Alright! We will follow that procedure when we start working on my friend's Camaro project. We'll take a closer look this weekend after installing the brake pads and mud tires on the Wrangler and clear the garage.

[Tarendor]

I had a weird leak like that one time and it was the oil pressure sensor behind the intake manifold.

[PlymouthBarracuda]

Sirs need any suggestions, I replaced both valve cover gaskets with grommets by made in china blue ones (255 sold), washed my car underneath, but after 5 days of daily drive oil appeared again.

Also removed intake and replaced oil pressure sensor (just for any case).

What is the symptom of the rear main seal and rear cover gasket leaking?

Oil comes somewhere from the middle part of the rear side of the engine... I opened a small round cap but its clear inside, Flywheel is clean

[morepowerjoe]

Originally Posted by PlymouthBarracuda

Sirs need any suggestions, I replaced both valve cover gaskets with grommets by made in china blue ones (255 sold), washed my car underneath, but after 5 days of daily drive oil appeared again.

Also removed intake and replaced oil pressure sensor (just for any case).

What is the symptom of the rear main seal and rear cover gasket leaking?

Oil comes somewhere from the middle part of the rear side of the engine... I opened a small round cap but its clear inside, Flywheel is clean

How many miles are on your engine?

[InFiD3ViL]

Originally Posted by PlymouthBarracuda

Sirs need any suggestions, I replaced both valve cover gaskets with grommets by made in china blue ones (255 sold), washed my car underneath, but after 5 days of daily drive oil appeared again.

Also removed intake and replaced oil pressure sensor (just for any case).

What is the symptom of the rear main seal and rear cover gasket leaking?

Oil comes somewhere from the middle part of the rear side of the engine... I opened a small round cap but its clear inside, Flywheel is clean

That inspection cap is exactly what I would have had you check next. You would likely have found some oil in there if it was the rear seal or engine cover, but not always. The only symptom you would really have is the leak itself and a messy driveway, and of course oil on the rear/bottom of the engine and trans.

Did you replace the oil cooler gaskets/seals yet? There are really not many other places this could be coming from on an LS. Sorry you weren't able to find it yet, hopefully it is something easy like the cooler. Some people will do an oil cooler delete due to how prone they are to leaking. If it's the rear seal/cover, it can get expensive if you have a professional do it. It's an easy and cheap job if you tackle it yourself and have the tools, time, and help - but is laborious since the trans needs to come out.

As for that lifter additive you asked about? Personally I would never add anything to these engines but a clean quality oil. The AFM lifters are already sensitive enough that I wouldn't want to introduce anything foreign into the oil. Just keep your oil clean and fresh. But that's just my opinion.

Are you able to tune cars in the UK? I would consider having the AFM turned off in the tune before I would add anything into the oil. In the states that is one of the first things L99 owners do.

[PlymouthBarracuda]

Originally Posted by morepowerjoe

How many miles are on your engine?

103.000 miles. Oil always used 5-30

[PlymouthBarracuda]

Originally Posted by InFiD3ViL

That inspection cap is exactly what I would have had you check next. You would likely have found some oil in there if it was the rear seal or engine cover, but not always. The only symptom you would really have is the leak itself and a messy driveway, and of course oil on the rear/bottom of the engine and trans.

Did you replace the oil cooler gaskets/seals yet? There are really not many other places this could be coming from on an LS. Sorry you weren't able to find it yet, hopefully it is something easy like the cooler. Some people will do an oil cooler delete due to how prone they are to leaking. If it's the rear seal/cover, it can get expensive if you have a professional do it. It's an easy and cheap job if you tackle it yourself and have the tools, time, and help - but is laborious since the trans needs to come out.

As for that lifter additive you asked about? Personally I would never add anything to these engines but a clean quality oil. The AFM lifters are already sensitive enough that I wouldn't want to introduce anything foreign into the oil. Just keep your oil clean and fresh. But that's just my opinion.

Are you able to tune cars in the UK? I would consider having the AFM turned off in the tune before I would add anything into the oil. In the states that is one of the first things L99 owners do.

Thank you so much for reply.

Are you able to tune cars in the UK? - yes but no firmware change. I use Range Device instead cut AFM system because on the highways I use AFM for 20% fuel economy (really works).

Did you replace the oil cooler gaskets/seals yet? - I have new gasket with 4 round holes, I am going to replace it together with engine oil pan gasket. Do I need to replace all other gaskets on oil cooler and all 4 orings ?

Oil comes somewhere from the back/top-middle side of the engine. Leakage is not intense, after cleaning I can observe it after 4-5 days only. There is no oil at all inside inspection cap . I have the Victor Reinz Engine Crankshaft Rear Seal Kit JV1657 with rear cover gasket, but transmission removal is required.....

What is the probability that oil comes from left head gasket ?

[morepowerjoe]

Originally Posted by PlymouthBarracuda

103.000 miles. Oil always used 5-30

I bought my 2012 with 150k and it had a bad rear main seal leak.