I recently bought a 93 camaro 5.7 engine from the states and has notice a fair bit if oil leaking out of it. When i got it home it seemed like it was up high and by the intake manifold gasket? Having said that i blow my transmission in the process of using it so i hauled out the transmission to get it rebuilt and while doing that i ran the engine so that i could find the leak as it would be eaiser to see so i thought.I dont know if this makes sensee but it seems like it is coming from the egr valve? I took the valve off and it was full of oil, can any one help me i am stumped?????

 

It is very common for the seal between the back edge of the intake manifold, and the back edge of the block to leak oil. It usually leaks closer to the passenger side, near the intersection of the head, the block and the manifold. The seal is a bead of RTV, and it appears the heat of the EGR riser pipe may cause it to deteriorate.

There is no reason for oil to be in the EGR valve, unless the valve is loose and the manifold seal leak is so bad the engine vacuum is pulling the oil in through the leaking EGR gasket - but I've never seen that happen. Are you saying there is wet oil around the EGR pintle and the two holes in the back of the manifold that the exhaust gasses flow through?

 

The leak is coming on the drivers side of the engine and i had the egr valve off and you can hear the oil in the valve with you shake it?

 

i CHECKED THE VACUM ROUTING FOT WHAT APPEARED to be a pcv valve in case its building up blow by gases as i do not have a tester for doing that. It seems okay but i did not see a pcv valve?

 

The PCV valve is on the driver's side of the intake manifold. On the 93-94 engines, the vacuum source is also on the driver's side of the manifold about 3 inches behind the PCV valve, connected by a short "U" shaped hose.

Did you look at the hose that runs from the throttle body to the passenger side valve cover? That line supplies clean air from the throttle body (passage in front of the blades) to the valve cover, and that is the air the PCV vacuum pulls through the crankcase and lifter valley to purge the blowby gasses. If the blowby gets too severe, the pressure blows the blowby backwards, carrying oil into the hose, into the top of the throttle body, and eventually into the intake manifold.

Shaking the EGR valve would simply be causing any internals in the vacuum diaphragm of the valve to rattle. I can't conceive on any appreciable amount of oil that would have been pulled into the vacuum diaphragm, past the pintle.

Are you sure you are referenceing the right parts when you are asking about the EGR valve, PCV , etc.?

Courtesy of Shoebox:
EGR System:

http://shbox.com/1/egr1.jpg

PCV (this is a 95, your 93 has a different vacuum source):

http://shbox.com/1/pcv.jpg

http://shbox.com/1/pcv_pipe.jpg

Hard to see in this photo of my 94, but this is the U-shaped hose:

http://www.injuneer.com/images/photo.../DCP04270a.jpg

 

I had the egr valve off in my hand and you can hear the oil sloshing around in it unless its being sucked in from the intake manifold/i DID CHECKED THE HOSE on the drivers side and there was some cracks in it so i replaced i think the problem is the intake maifold but whats throwing me off was the oil in the egr vavle i am thinking of blocking it off for not.I will check on the pcv as you sugeested but i got to tell you i dont need to undercoat the car what a mess of oil.

 

It defies all logic that the EGR valve vacuum area could be full of oil, or that if it was that it would "slosh". The pintle slides through a seal in the part of the valve that attaches to the manifold. To get oil into the vacuum volume, the oil would have to be leaking OUT of the port in the back of the intake manifold. That port is under full manifold vacuum - if the seal leaked, vacuum would pull air into the intake, not push oil out of the intake. The manifold passages to the port are narrow, and go forward to combine with the IAC flow. How would the oil that collects at the throttle body, from the line to the passenger side valve cover, travel all the way to the back of the manifold, via the internal EGR passages?

The vacuum portion of the valve also has a seal on the pintle rod. If you had a vacuum leak at that point, it would pull air in from under the hood, not from the manifold. The only possibility is that the EXTERNAL portion of the intake manifold is so wet with oil - either from the manifold seal to the block, or from a leaking plugged oil port on the back of the block. Even then, oil would have to flow uphill to get to the PCV valve.

 

Hey i cant explain it either unless the vacum to the egr doesnt work? I mean there is oil every where so i am going to strip it down and see whats on the go makes no sense to me either, i will let you know how i make out.