Question : EGR question

[AeroNed]

When I replaced the head gaskets in my 3.1 I removed the EGR valve to find it gummed up with the milkshake of oil and water. I can't think of how that mix could get into the EGR. One side is the exhaust and the other side is the intake manifold. The passage to the intake was also plugged with carbon. The car wasn't running it's best, obviously, but it was running. Could it really have come in through the exhaust?

Anyhow, the result is that the engine is running great now. No more leaking oil or water.

[60dgrzbelow0]

I know this will be a kind of "Closing the Barn Door AFTER The Horses Got Out" kind of repair article, especially since you've already done the repair... but at this point, you should suspect that you either have a warped or cracked engine head(s) or in a WCS (Worst Case Scenario) a cracked engine block...since neither the coolant nor the engine oil are capable of either cooling the water jackets around the cylinders and heads properly and hot spots will rapidly conspire to warp things quickly...or... lubricating bearings and surfaces because that "Brown Pudding" is not really an oil any more, nor is it capable of lubricating anything properly once this disgusting and useless mixture develops. Reading this and other articles like it on THIS forum might cast some candle light on this very unfortunate darkness. A decent machine shop should have a look at those heads and see if anything really bad happened that they can fix or make true and flat and smooth enough to seal up again properly with another new set of head gaskets.

One important thing to remember about all Aluminum Heads is that when REMOVING them it is critical to follow a REVERSE TORQUE SEQUENCE to the factory install torque pattern on a STONE COLD ENGINE. This is because releasing the "squeeze" on the heads in an out-of-order or chaotic pattern can induce flexing and twisting stresses that will warp the heads for THAT reason alone! Other wrenching folk here might disagree with me on this point...but why take any chances and risk it? There is enough logical evidence to support doing it this way to avoid adding one problem on top of another. I think we can all agree that Iron Heads may not be so particular... because there simply is no comparison between Iron Heads vs, Aluminum ones when it comes to the aspect of real rigidity and stability in the metals' characteristics. Iron Beats Aluminum like "Scissors Cut Paper".

http://williamgreen.hubpages.com/hub/Chevy-31-Liter-Engine-Leaking-Intake-Manifold-Gasket-and-Warped-Heads

https://www.felpro-only.com/tec_notes/Fel-Pro_Torque-Guide.pdf