Chuck314

After I detailed my Vette's exterior and interior, I opened the hood and started cleaning the engine compartment. To my dismay I found a layer of oil floating on top of the engine coolant, in the coolant tank. It isn't thick, but it is noticable.

Is this a death sentence to my stock L-98?

About my car, the entire car has 50K miles and all original. It's a 1988 35th Anniversay Edition, pampered garage queen.

383vett

Head gasket, or radiator cooler leaking into the coolant. Hope it's #2.

leesvet

Well,. its certainly not good..

Look at the PCV valve to see if there is ANY foam or gel in/on that. Also look at the eng oil dipstick on the stick and around where it seals on the tube for further evidence. Pop the radiator cap off to see whats in there too as well. Look for slime or foam on the cap rubber seat and inside the filler neck.
Oil in the water... means there might be water in the oil as well. Depends on the injury. It does not mean there IS a wound somewhere. Thats why you want evidence in these other places. Sometimes there can be a drop of oil thats been circulated and in the cooling system since it was assembled and thats what you;re seeing. The slightest bit will make a slime of sorts. If there is no other sign of oil anyplace else, I'd remove that stuff in the coolant tank, refill and observe it closely for the next few hundred miles for more evidence.

If you DO find other places with slime or foam then you have to assume that its more than casual contamination. there is a leak somewhere.
Most often its something in the heads. L98's have head bolts thru water passages that have to be sealed or the water seeps past the threads into the oil. Head gaskets are also suspect. Once in a million yrs something like the O-ring seal in the eng oil cooler fails and allows some mixing. Thats a simple fix, IF it can be identified.

1st look at the other things, dip-stick etc...
Then if there is cross contamination start pulling spark plugs to find a cyl that will tell you if the heads/gasket is involved. If it was ever overheated and not cooled properly or extremely overheated, heads are involved. The aluminum has its limits to what it'll take as far as temps and rapid temp changes.
Sounds like a darn nice car....I hope its nothing too serious. Let us know what you find..

STL94LT1

If the car is an auto, it could be the trans cooler in the radiator damaged/leaking.

Chuck314

Hey guys thanks for all of your input, it's truely appreciated. I'm going to stick my head under the hood on my next day off from work. I forgot to mention that my car is an automatic.

I'll give you guys an update after I take a look.

Thanks again,

Chuck