I have a 1996 Honda Accord LX with a little over 230,000 miles.

Lately, it has randomly started overheating after around 20 minutes. I checked the antifreeze and it is full. I think the radiator cap has been on the car for well over 100,000 miles because I bought the car with 140,000 miles on the odometer.

I have noticed that every time I turn the car off the fan comes on and stays on for a few minutes.

Any ideas of what it could be? The waterpump was replaced at around 160-170,000 miles.

 

A flaky ECT switch or fan relay come to mind. I suspect if your thermostat were bad that it wouldn't be so random. But then again, I'm a mechanical guy and I don't trust electrical things. Any idea how old the thermostat is? I make a habit of changing them periodically rather than waiting for them to fail, especially on cars that have aluminum heads. That's just me, though.

 

basket case is right. It's best to be proactive on thermostats and really anything cooling system related so as not to allow the engine to overheat and/or get stranded.

Only go Honda OEM when it comes to thermostats. They have builtin failsafe and last a lot longer than aftermarket.

 

Update: got the thermostat replaced and filled her up with antifreeze. Back in business! I am guessing that was the original and with 231, xxx miles she was overdue.

 

I doubt it was original. That's a lot of miles. Plus, OEM thermostats will fail open and won't overheat. Your car will just run colder than it should.

 

Oh so you think it was aftermarket? At any regard, I bought the car with 140,000 so it lasted at least 100,000 miles with me.