[/quote]Are you familiar with the parts of an engine at all? This will be hard to explain without pictures if you aren't. When you open the hood you'll see "3100" stamped on the upper intake (or plenum). This upper intake is bolted right on top of the lower intake. The lower intake sits between the two cylinder heads of the engine. The intake gaskets that I'm referring to are between the lower intake and the cylinder heads. You won't usually see a big leak like dripping or anything, but what they'll do is seap and it can look like a foamy build-up on them. Also check the oil for signs of coolant.[/quote]
Yes, pretty familiar, but just not with GM motors. Since I have the car here this afternoon I was able to check. Ok, I found where the lower plenum bolts to the heads, and yes on both sides there is a thick brown/black seepage on the lower half of both sides. (it isn't foamy, but rather just thick greasy/nasty looking and has attracted dirt as well). Also, having just driven the car, I took notice of the coolant and have found that it is down about 1/2" below COLD on the reserve tank. (the car was just driven about 10 miles in 85f temps.)
Looking at the dipstick, I don't see anything obvious besides dirty oil, BUT peering WAAAY down in the reserve tank (there is about 3/4" of coolant in the bottom. I see something on top of the coolant, that looks thicker and is kind of forming swirly patterns on top of the coolant. Whatever it is, (oil?), it is basically the same color as the coolant (dark red).
Ok, the coolant is VERY low. There is something making little swirly trails on top of the coolant. Lower half of the intake gasket (between lower plenum and heads) has a clingy, dirty thick consistency coating on it on both sides. Reserve tank is very skinny and wide, but inside of tank is VERY dirty.
Should I hazard a guess that oil is getting into the cooling system and also seeping out this gasket?
If so, this particular one is out of the running..
Please let me know your thoughts..