overheating while idling, normal while driving

[ac3]

My car runs hot and has overheated a few times while idling, once while stuck in traffic... But driving above 30/40 mph the temp drops back to normal. Is this a bad thermostat issue?

[jbe21]

could be a bad water pump. does the temp drop if you rev the engine for a bit?

[3vilE30]

You need a new fan clutch.

[Farbin Kaiber]

Newspaper fan clutch test time.

[TobyB]

Could be a lazy t- stat.

Most likely lazy fan, though.

Less likely (not impossible) water pump.

t

[xdavesmithx]

test the fan clutch, as replacing it is a much easier job than a water pump. if that tests fine, try revving the motor a little while you're sitting still and see if the temperature goes down