Today i bought a Non running 2000 Tahoe from an auction. it doesnt turn over so i checked the oil (before checking if the engine was seized) and found brown thick sludge on the dip stick. so i pulled the plug and started draing the engine. While it was doing that i took a look at the intake filter and the same brown sludge was in the filter and the pipe leading into the engine but not going the other way out of the engine (so it came from the engine) my thought was that maybe the air intake gasket had blown and alowed coolant into the oil. At this point i checked to see if the oil (sludge really) was done draing and it was still going but was at the top of my 12 quart bucket (where is this all coming from) so i switched the bucket and its still going and is about another 6 qaurts atm filled to give you and idea this brown sludge is the color and thickness of brownie batter but smells like oil?...anyone have any ideas ?