1996 Chevy Lumina Engine keeps overheating

BRANDIF

MEMBER
1996 CHEVROLET LUMINA

Engine Cooling problem
1996 Chevy Lumina 6 cyl Front Wheel Drive Automatic

While my car is idling the temp seems to be fine, but once I start driving it the temp starts going up. The faster I go the faster the temp seems to go up, until it is at the redline and the dummy light comes on. For awhile I was able to turn on the heat full blast and it would keep the temp down to just below the redline, but now that really doesn't seem to be working. The samething goes for when I turn on the air conditioner. It seems though that the slower I go or if it's just idling the temp stays the same if not go down a little more. With both the heat and then the air conditioner going the fans do run. I thought at first maybe I had a bad fan sensor, but now I'm thinking it might be the thermostat. But I'm not sure where the thermostat is. What do you think as far as the car overheating and if it is the thermostat where do I find the thing.

Thank you so much for your time and help with this matter.

Brandi F

2 Replies

BLACKOP555

MECHANIC
10,371 POSTS

Try a cleaning out the cooling system with a flush first of all.

Then make sure the thermostat is functioning properly.

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Tuesday, July 22nd, 2008 AT 9:38 PM

DNAPRORACING

MEMBER
120 POSTS

What Can Make an Engine Overheat?

Overheating is caused by anything that leads to a loss of coolant, prevents the cooling system from getting rid of heat, or causes excess heat in the engine itself:

Coolant leaks (water pump, radiator, heater core, hoses, freeze plugs, head gasket, engine internal).
Weak radiator cap (does not hold rated pressure and allows coolant to boil over). Pressure test the cap to check it out.

Cooling system clogged (deposits built up in radiator or in the engine due to maintenance neglect or use of hard water). Use a cleaner, then reverse flush system to clean it out. A badly clogged radiator may need to be rodded out or replaced.
Thermostat stuck shut (replace).
Inoperative electric cooling fan (check fan motor, relay and temperature switch for correct operation).
Bad fan clutch (replace if slipping, leaking or loose).
Missing fan shroud (reduces cooling efficiency of fan).
Slipping fan belt (tighten or replace).
Too low or too high a concentration of antifreeze (should be 50/50 for best cooling).
Bad water pump (impeller eroded or loose - replace pump).
Collapsed radiator hose (check lower hose).
Debris in the radiator (remove bugs & dirt).
Late ignition timing (reset to specs).
Restricted exhaust system (check intake vacuum readings and inspect converter, muffler & pipes).
Radiator and/or fan undersized for application (increase cooling power by installing larger radiator and/or auxiliary cooling fan).