1999 Deville base
95 Eldorado, 99 Deville, 05 CTS
Hey guys! My old high mileage 250k+ Eldo keeps overheating, right on into 230+, just idleing, or driving. Uses no coolant. Passed the expansion tank blue liquid test. Liquid never changed. Still pretty blue, even after 10 minutes of testing, after engine had just been over 230. Took out almost new radiator and cleaned it. It was good. Drained block. Removed thermostat and flushed block till clear, then put Blue Devil cleaner in. Been in for 4 days now, starting and letting warm up to 230 a couple times a day, no change. Only thing else I can think to do, is put the compression tester on each cylinder and see if its blowing any bubbles. I still think it's the head gaskets, but it's not using any coolant at all, the exhaust ends look great and it passed the blue liquid test! Anybody have any other ideas? Hate to give up on the old girl. Still runs good. Thanks for any replies!