Trying to track down and repair this oil leak properly. I already replaced the valve cover gaskets and the are dry as a bone. I did noticed some fresh oil along the head gasket to block area.

It apears to be mostly leaking from the rear of the block. We had it in the Air on a lift and the rear main seal looks dry all over. I was thinking maybe the rear engine cover is not sealing and it may need a new gasket. As far as I know It has always had the recomended mobile 1 in it. Since it looks as though the motor has to come out to fix it, I was thinking we would just change all the Seals and gaskets, maybe even through a ZO6 cam in it while its out.

Any one else have oil leaking onto the exahust in there vette? What did you have to do to fix it?

 

Detailed picutres?

I'd say the valve covers although you've ruled that out...

The valley cover (if it's ever been off) or the rear cover (if it's ever been off)

IF both of those comonents have never been removed from the engine I find it hard to believe that those are the culprits. The LSx engines are not prone to leaking when sealed from the factory...

Perhaps it's the PCV hose system maybe from the driver's side at the rear of the valve cover that's migrating along the back of the engine bellhousing???

 

In fact... when I think about it more... I'd say it might be the PCV hose itself...

They come together from two juctions (each valve cover) at the back of the engine. Maybe during removal/install the junction isn't pushed together completely.'


Take the entire Driver's side to passenger side PCV hose assembly off, I'd bet you find oil at the junction.

 

Thanks!
Far as I know it has never been apart. The valley cover has alot off dirt debry build up that I can see from the front under the intake so may be that is the issue... after all I see it around the heads were they seal to the block but there is nothing coming from the valve covers since I replaced those and cleanead the area very well before I put it all back together. I will look closser at the PVC system tommorow. That burning oil is nauseating...

Thanks!!!

 

By the way I see oil driping mainly in the rear on both sides of the bell housing. Really makes me think that valley cover may be the culpret... I guess it is easyer to take the intake off then it is to pull the whole motor.

 

I will look into that Too! Thanks

 

If the oil is coming out of the headers, then its a valve seal. other than that, its probably what you all are talking about. sorry for little advice, but i need pictures or for you to be more specific.

 

It's leaking ON TO the exahust at the rear of the block down the bell housing area.

 

The knock sensors can leak, (rubber seals around them). They are in the valley pan and oil can come up the holes that they sit in.

 

Intresting... Not sure if were gonna look at this week or not but if we do I will post up what I find. He (My boss) seems to be over the car in general and has apparently listed it for sale...

 

Looks like it was the oil pressure sensor at the rear behind the Intake manifold. After pulling the manifold off, I was able to see the sensor was covered in oil. I unpluged it and removed it. When I pulled the plug out of the sensor the weather tight conector also had oil in it... apperantly it is made of Gold Too Because the dealer wanted $70 our cost for it... Whats amasing is They did Not have a valley cover gasket in stock or that Sensor. they did have the intake gaskets though. We Used our local parts supply house and got the sensor and intake gaskets for around what the dealer wanted for Just the sensor. The boss didn't want to spend the Extra $20 on the valley gasket...

Any way I hope this helps some on else out if they have a similar leak.

 

I had to replace that sensor too (due to failure) .... was your oil pressure pegged at 80 psi?

Glad you got it...

 

Apperently it was pegged on the high side. When I removed the intake, it was obvious because it was covered in fresh oil. Even up the plug wires had oil on it. some how it was leaking through the plastic area... when I pulled the plug out of it, there was even oil inside of that area... Go figure....

 

Your not going to believe this... Wiring issue Now. apparently It was peged before like ~Joshua had. Now it started fluctuating saying the pressure was as High as 130 something PSI which is obviously not the case at idle. then it would go to Zero and say low oil pressure warning. after patching that area of bad ground we got intermentant fluctuation between 40PSI and 0 PSI....


We found a dead spot on the ground and replaced that section of wire. Either the constant 5 volt source has an issue some were or the Signal wire has a dead spot... Need less to say after waisting the day Between customers We decided to run new wires from the computer. I think I had the intake off 3 seprate times trying to fix this issue...

The best part of this ordeal today was when He lifted it from the wrong spot and cracked the fender.... Now He knows why I won't touch the wiring or put it on the lift for him.

 

I've had that damn oil pressure sender go bad 4 times. Was bad when I got my car 4 years ago. They are REALLY SHITTY. None are any better, I tried an aftermarket one from Autozone too. One GM unit, lasted literally a day. Then had the same symptoms as yours. I wouldn't be surprised if it's the sender. That is a common symptom for a faulty one.

Been good for like a year now, with a new GM one. I have my intake off right now to replace a knock sensor and I'm paranoid of screwing the damn thing up. lol..

Good luck
Steve.

 

I hate to say it but thank god its not my car because I would bypass it and go mechanical just to eliminate this damn issue. The sensor cost $70 and like I said we had an issue with the ground wire on the Plug haveing 2 breaks in it.