1998 Chevy Lumina Car heat comes and goes

TJPJWE

MEMBER
1998 CHEVROLET LUMINA
6 CYL
FWD
AUTOMATIC
17,100 MILES

I have a 1998 chevy lumina with a 3.1 motor. It recently started losing heat. I can watch the temp. Gage rise 3/4 of the way. At this time, I will have no heat. It will drop quickly and then I have heat. The temp usually does not drop until I am driving and will start to rise if I am at a stand still. Once I move, it will drop again. When it drops, I have heat again. My fan is working. Could this be the thermostat or could the cooling system need purged. Also, when I turn the car off I have noticed a gurgling noise that sounds like it is coming from near the overflow. I don't think it is the head gasket as I have no smoke, no milky oil and no oil in my antifreeze. Any suggestions?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

The gurgling noise tells me it's overheating. As far as the heat, I would think the hotter the engine, the hotter the heat. Therefore, it leads me to believe there is a blockage. If the fan's are working, it shouldn't heat up when stopped. . The thermostat doesn't fit as a problem. I question a partial blockage in the radiator (flush) or a water pump going bad.

With the engine cold, open the radiator. Start the car and allow to warm up. When it hits a normal operating temp, the t-stat should be open and allowing full flow of the coolant which you should be able to see in the radiator.

Let me know what you find. Also, feel both upper and lower rad hoses for temp, and both heater core hoses.

Joe