Sorry hope these pics come out.

 

Mine is leaking from the exact same spot. I will find out what it is this week. Let us know if you beat me to it. I'll be using some dye to pin point my leak.

 

I will try to find out exactly what it is. I hope not the rear main. I feel better now that the Junkman is here.:thumbsup:

 

Going on 3 years buddy. My favorite forum by far. :thumbsup:

 

Oil leak help please. It seems like it is coming from above the starter.

 

Okay, so I found the source of my oil leak. It was not the rear seal (thank God). It was a combination of two things. My camshaft position sensor and my oil valley pan gasket. I will do a basic write up here soon but this is for those who may be experiencing the same leak as I had.

The way that I figured it out was by looking at exactly where the oil was leaking. It was coming down and around the bell housing, which told me that it was coming from the top of the motor somewhere. The only thing that I knew of that could leak oil from up there was my oil sending unit. Since I had relocated my sending unit, I thought that maybe my adapter that replaced my oil sending unit was leaking. That was not the case. In this picture, you can see that the adapter was pretty much bone dry. However, my cam shaft position sensor was caked with oil (already removed in this picture).

Here's a shot of my camshaft position sensor. Notice the blue gasket around and near the bottom of the sensor. There should NOT be any oil up past that blue gasket. Mine as you can see does. Since oil was being forced up past that gasket, that was one of my two places that oil was leaking.

By looking at this next picture, you can see that oil is present at the front of the motor, where the throttle body is located. There should be no evidence of oil at that location.

Because of these findings and the fact that I had disassembled this much stuff, I decided to replace the oil valley pan gasket too. There is no other location on the top of the engine that oil is pressurized that I haven't addressed so I figured that this would solve my issues.

If you replace you cam position sensor, you may have to perform the Idle Learn Procedure. You may also need to reprogram your fobs, as detailed in your owner's manual. The fob thing baffles me but that's what the service manual says.


After reassembly, I cleaned the engine and undercarriage and then took the car out for a serious thrashing. All evidence of leakage was gone.

This has solved my issue and hopefully will resolve yours too. :thumbsup:

Here are the GM part numbers for the items I replaced. The cam position sensor:

The valley pan gasket:

Here's a wide shot for orientation purposes (for those who would need it like me ):

 

That is good news for you. I guess I will start this project soon. I have never removed intake before. I hope this is the same leak I have. Thanks

 

Does you engine show evidence of leakage forward of the valley pan gasket? If so, you are in the same boat as I was. If you use my instruction for replacing/relocating the EOP sensor, removing the intake is a breeze. I will also do a writeup for this to include the valley pan gasket and cam position sensor.

 

Outstanding write up with pics Junkman.:thumbsup:

 

Thanks Sarge. I'm in your neck of the woods this weekend. I did a detailing clinic in Atlanta. Are you anywhere near the freeway that I'll take to get back to Louisville?

 

I will check to see if oil is around the valley pan this weekend. I ran into being assistant coach for my sons baseball team and time to work on toy has been put to the side for now.

 

Yes. I have oil on front of valley pan and all over pcv vaulve. Every thing is kind of oily and dirty. This is a must clean and fix now that I have seen how messy the engine is now. Thanks for pics. Local parts had the cam sensor for $45. Should I use this one or go to dealer?

 

That's totally a preference thing. Some things, like a windshield washer motor are not critical to the car's operation and I won't pay dealer price for them. The same for the coolant overflow tank. Something critical to the engine is a different story. I'll pay full price for that gasket. I didn't know how critical the cam position sensor was but it sounded important so I got the GM one.

 

Mine is leaking also first I thought it was the PCV hose because it was dry rotted in 3 places,which probably caused some oil leakage,I changed my valve cover gaskets next will be intake and lifter vally gasket,good write up Junkman very helpfull..!

 

Okay. went to change cam sensor for oil leak and that was not the problem. It was the pcv hose connecting the vaulve covers around the back of intake. It finally broke in half and oil was all over the engine. Anyways I change it out and put new intake gaskets on started the car and now a loud hissing sound. Any ideas?

 

:laughing:

YEP! I know exactly what you are hearing. Look at these pictures:

Now guess what you forgot to plug back in, or THOUGHT you did plug back in but has came loose?

 

NO way. I know I plugged that little hose in. I checked twice before bolting things down. Please tell me that is not it.

 

Well I just checked and I guess when I ran the new pcv hose around the back of intake it knocked it loose. :thud::thud: Anyt ideas on how to fix without going threw all the trouble.

 

The manifold does NOT have to come off, but it has to come forward in order for you to connect that hose. So basically, you've got to damn near remove the thing again. Don't worry, you ain't the only one who has made that mistake at least once.

Been there, done that!

You won't make it a second time! :laughing:

 

Well the second time was alot faster. Leak fixed it was the small hose in back. Thanks for the write up Junkman it helped. I would have never attempted this project. I got neighbors thinking I am a mechanic now.

 

Glad you found it useful. It's all about the Corvette brotherhood. :thumbsup:

 

Now I have a check engine light on. Any ideas on this one? No I did not have any engine light on before I took intake off and put back on. First time it has ever said check engine.

 

I put a sticky at the top of C5 general months ago on this very topic. Get your reading glasses on and say hi to Daisy for me. :thumbsup:

 

I told Daisy Hi for you and thanks again. The more I work on this car myself the more I love it. Just cleared my code. A little prong on the MAF was bent and I fixed following the codes the engine gave me. I learn every day thanks to you and others. By the way it was not my cam sensor causing the leak in the back like the rear main seal. It was the pcv pipe going around the back of intake. Broke in half $112 at the dealer.

 

Was the break on the passenger's side and did it mainly leak when you got on the car real hard?

 

It was in the back. when the 2 pipes go into 1. That is why I thought rear main seal and cam sensor. Well I just got back from taking it out and just found another little spot of oil on the ground. I will give it a few days hoping it might be from old stuck on motor and running off. If not I have to go back in and change cam sensor.

 

Did you save the old parts that were bad? I'd like to see a picture of the messed up hose.

 

Here you go.

 

Let me know if pics are coming.

 

Yep, got'em. I thought that you were just going to replace the part that was messed up. I didn't realize that you replaced the whole thing. That explains the cost. By the way, here's an alternative way to post pics. :thumbsup: