I have a 1999 Cadilliac Deville and it get overheated after 20 to 30 minutes. I have changed the water pump and thermostat. But it still gets hot.Could a clogged radiator cause it to overheat? Can anyone help me?

SOURCE: i have a 1999 cadillac deville thats running hot

Have you replaced the drive belt(s) and/or checked the tightness of same?

SOURCE: ford ranger truck overheating

I have had this happen with my ranger. Changed everything I could to try to fix the over heating. It turned out that I had a small leak in my head gasket and it was allowing exsaust gas to go into the cooling system witch was over pressurizing it. Also the air from the exsaust will heat up much faster than liquid making your thermostat to read hot and will not be able to blow hot air in the cab because there is no liquid going to the heater core. This happened to me when my blet came off and I tryed to make it home. If you had it over heat for a long peirod of time it may have ripped the head gasket.

SOURCE: Overheating engine

Check your oil dipstick for coolant, or a mucky substance. Your symptoms sound like a blown head gasket.

SOURCE: 93 lexus gs 300 overheats. i changed water pump,

Try blowing the radiator fins out (from the inside) with compressed air--bugs and other debris can clog the air flow. Do the radiator fan(s) run when hot? If not, check for blown fuse, seized fan motor(s), bad relay, or bad engine thermal sensor. Is it losing coolant water from somewhere?

SOURCE: 2004 Pontiac Grand Prix OVERHEATING!!!

Have you shop perform a "leakdown test." You probably have a bad head gasket )or a leak in the gasket).