Hello everybody, I just bought a used 96 DeVille Concours and the dummy temp gauge in the dash has it reading HIGH up to 239!! But the car is not overheating, nor is the expansion tank leaking coolant or boiling etc. I don't smell exhaust in the tank either. The car has had a lot of work done to it including a new HG. So somewhere along the line it did have issues but the car and engine seem to run fine except for that coolant temp. gauge keeps rising. the two electric fans come on properly too. When I'm driving it won't get that high only while it's been sitting in my driveway. while on the road it's in the upper 200's. I know one should turn the on the heat full blast but my blower motor does not work so I don't even have that option. Yes I know, why did I buy the damn car in the first place. Long story. anyhoo, best advice from anyone? Isnt' there a tool to check for the levels of exhaust thats in the coolant? I'll go that route I guess. but some encouragement would be nice. thanks to all.