91 Integra Sudden Overheating

is your fan comming on ? to you have power to the fan motor? bad relay ? water pump?

also could be a fan not kicking on check your relays when it gets hot your fan should kick on if not check it or a water pump going out

machine snipped-for-privacy@yahoo.com writes in article dated 14 Sep 2005

I think you may be mistaken about that last part. The thermostat controls how much coolant flows to the radiator. The heater lever controls how much goes to the heater core.

Your problem is almost certainly a stuck thermostat or some other flow problem on the way to or from the radiator.

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

The giveaway here is that "at a cold start, the temp goes to normal, stays there for a few minutes then starts to climb quickly." The engine warms up, the thermostat opens, the rest of the system gets hot, but the radiator can't get rid of the heat.

If the water pump fizzles (and, yes, I remember one ninny who couldn't recognize a broken fan belt...), the temp will simply keep rising. It won't stay "normal" for a few minutes. And, if the (presumably electric) fan doesn't run, it usually doesn't matter at highway speeds. Usually, the electric fan is needed only when driving slowly or when stopped.

The radiator is almost certainly partially plugged.

Run the car until the temp. starts to rise above normal. Shut it off and feel of the radiator. It should be uniformly hot all the way across. I'm betting it will be hot in a small area and the rest (the plugged section) will still be cold...

Jerry