Overheating/ heater hot and cold [Archive] - GrandAmGT.com Forum


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12-01-2004, 02:04 PM
I have a 2000 GT. I know I need to have my coolant flushed and changed. But for the past 5000 miles ( I have 100,000) the heater would blow hot air for a while and then would blow cold air. Back and forth always (hot for 5 min., then cold 5 min.) Recently, the temp goes up and starts to overheat all while the air is blowing cold. When it blows hot the temp goes down. It's not the thermostat because that was what I changed first to see if it would help. The last time I drove it, the car died twice on me. After letting it sit for 10 min. it was able to start again. I don't know what it is? Can it be the heater core?, water pump?, belt? Possibly just a coolant flush? Help me out
Also, if you know what it is, how do I fix it and how much $$$ will it cost me?

(I have a Borla exhaust, not sure if that matters)

-not the coolant, that level stays fine. I took it into the shop today (Thurs 12/2) he said sounds like it might be an air pocket in the cooling system. I'll find out tonight hopefully

12-01-2004, 02:51 PM
Check the Coolant level, it's probably low. The real question is where did the coolant go. It might be the water pump, but you could have a gasket leak on the intake manifold (very common).

The heater uses coolant running through the heater core, so if you're out of coolant, you won't get any heat. Do a search on "heater" and you should get more info.

If you are losing coolant, you have to replace/fix the culprit. If you're lucky it might be the waterpump, which relatively cheap to fix. If you're losing coolant through the intake manifold it's an expensive fix (in labor, parts aren't all that bad).

12-01-2004, 04:19 PM
Yeah, sounds like low/bad coolant.