# 85 nissan (z24 motor) overheating



## black out 85 nissan (Jun 15, 2011)

My 1985 nissan just had a thermostat put in it and the motor over heats within 30 seconds of starting up. i think it could be a water pump issue. But i would like to hear others opinion on what could be causing this issue. thanks


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## smj999smj (Jan 1, 2006)

If it was overheating before the thermostat, I would seriously be considering that the head gasket is blown. WHen water pumps fail, usually it's the shaft bearing that fails and it's pretty obvious. Restriction in the radiator, or restricted airflow through the radiator core, are possibilities. If it's fine while driving at highway speeds, but overheats while sitting or in stop-and-go situations, the fan clutch is the usual suspect. If the overheating started immediately after you replaced the thermostat, I would suspect a faulty thermostat.


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