Alright, I have a 1992 Acura Legend and last time I tried to drain and fill the radiator I found that there was motor oil (or sludge)in the radiator. I thought it could be a broken head gasket but I'm not so sure. Do you have any other ideas of what it could be?

 

Also when the car would be just started up it does not have a steady idle. It would rev up to 4 then drop back down to 1, then back up to 4 then down to 1...it would do this for a little while then seize down.