02-06-08, 06:02 PM
I have a 1998 Sedan Deville N* and it's over heating on me. Bout 2 months ago the radiator sprang a leak so I replaced that, then the water pump went out, changed that after buying the hard to find tool. Anyways the other night I was stuck in heavy traffic and the car overheated. The top hose was tight when I pop the hood so I assume it was the thermastat so I replaced that this pass weekend. Well today two days later it overheats again. I wasn't far from the house so I let it cool and drove it back home. I put some fluid in it and let it run for 15-20 minutes to see if it would run hot again and it didn't. I'm confuse can someone plz help me out. Thanks
02-06-08, 07:18 PM
When you replaced the radiator did you get the fans and bracket in correctly? How about the wiring......does it look OK? Check in the fuse box and look at the 2 fan fuses and relay(s)......AOK? (diagram in box cover). Do the fans spin easily by hand? How about the connector to the coolant temp sensor down under the throttlebody. These engines run at 16 psi hot, so the top hose would be hard. The 50/50 DEXCOOL coolant should be halfway up in the surge tank, or at the arrow mark cast in the side.
When you let it run for 15-20 minutes, did the fans come on? There's a purge line from near the water pump to the surge tank upper level, about a 3/8" I.D. line....is it free and clear?
Yeah, you probably had air in the system from the pump & stat change. If the purge line is clogged you will overheat.
03-01-08, 12:26 AM
Thanks for the advice, I parked the thing for a few weeks to think this thing over.
All the necessary wires connection fuses all O.k. Fans are turning freely. Not quite sure about the purge line. Will check this week end and update.