: coolant too hot

05-01-07, 05:54 PM
heres my situation i have a 02 deville when i turn the car on and leave it running it will be fine once i start driving 10 to 15 min later it starts overheating first i get the coolant hot then i get the engine hot on the display i pull over and my coolant tank is burning hot pretty much it only overheats when the car is actually moving sometimes when it starts to overheat i pullover and it will cool down a little what i want to know what causes my coolant tank to get so hot. I JUST GOT A NEW OEM WATER PUMP,THERMOSTAT, AND CAP FOR THE COOLANT TANK PUT IN TODAY. if anyone has any ideas please let me know. thinking it might be the headgasket.

05-01-07, 07:29 PM
I'm guessing a faulty pump OR the belt or tensioner were not re-installed correctly. The belt may be slipping for some reason, which is what it sounds like. I don't know enough about how the system work s to comment on the stat.

When you say OEM you mean GM right?

05-01-07, 07:45 PM
Do a cylinder pressure test to confirm or rule out head gaskets if you suspect them, then go from there.

05-01-07, 08:53 PM
Doubt its the headgaskets, especially on an 02, definetly sounds like something wasn't put in right. Unless your oils milky,coolant is in ur exhaust, or its pushing coolant out the overflow.

05-01-07, 09:49 PM
yeah parts are from cadillac dealership . there is alot of air pressure in the coolant tank. how much does a cylinder pressure cost.

05-03-07, 11:16 PM
Go to a radiator shop and have an exhaust gas (combustion byproduct) test done. They will do it much cheaper and faster than a mechanic. If it's positive then you probably have blown HG's and you can verify with a cyl pressure test. If negative you can eliminate them.

05-04-07, 12:24 AM
Doubt its the headgaskets, especially on an 02

Come on now... tell me you dont REALLY believe that...

Go ahead and get the tests above done, and check your tank for bubbles. Im hoping for your sake someone screwed something up, will keep my fingers crossed.