My car continue to overheat while running in idle or at low speeds
I have a 2007 Pontiac Grand Prix gxp. My car
overheats while at idle and or low speeds. On the
highway it is fine I just had the coolant flushed but
it is still happening I also replaced the radiator cap
Symptoms of overheating at idle are low coolant level, bad thermostat, rad fan not coming on, head gasket or water pump impeller corroded or broken.
I agree with Tom. Look at the fan operation, coolant level and thermostat first. You will probably find the problem with one of those and they are simple to fix. Water pump and head gasket are significantly harder to repair and should not be attempted by a novice.
And who did your coolant replacement? Air trapped in the system after being drained and refilled is extremely common and will cause overheating. If it was a shop, they probably knew to bleed the air out and its likely OK, but if it was a do it yourselfer project you might want to check again for air in the system. There is a bleeder valve near the thermostat.
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