Michael Johnson

I have a 2000 Civic EX with 238,400 miles. About 3 months ago, the temp gauge starting dropping when I would get on the gas to accelerate at a stop sign or passing someone like that. Then, the car started running hot. I replaced the thermostat. Float issue remained, overheating remained. Long story short, I ended up replacing the engine temp sensor, coolant temp sensor, fan relay, fan switch....still, overheated after 5-7 days or driving. Would work fine for a week and then would start running hot. Finally ran it a little too hot and blew the head gasket. Ended up being the water pump was failing, had new head gasket installed and a new water pump all done by a certified mechanic. I got the car back that night and the check engine light was one (mechanic had forgot to reset after his work). Reset it, and I still have a knock sensor code (which I'll fix later) and something just doesn't sound right, sounds almost like an exhaust leak or a vacuum hose off or something....just sounds a little ragged. I've had the car back for about 4 weeks now and all of a sudden yesterday, the freaking temp gauge is floating again. I asked the mechanic and he says definitely thermostat. I replaced the thermostat to no avail. Any suggestions or ideas at this point in the game?

New water pump, new head gasket, new engine temp sensor, new coolant temp sensor, new thermostat, new fan relay, new fan switch, full of coolant.....and the temp gauge floats when I accelerate. I'm at my wit's end with this car but broke as a joke and can't afford to get a new one .

mac25

Are you sure the fans are turning on?

If it cools down while you are driving, that is because air is flowing through the rad.

If your overheating is only when you come to a stop/low speed, then I would look at the fans.

Take her for a hard rip, then pop the hood, if the fans are not blowing then there is a fan issue.



Until you figure it out you can also use a jumper wire across the fan switch to make them permanently run (while the ignition is on).

Michael Johnson

It ended up being the electric temp sender. The black plastic plug end had cracked and was loose. I fiddle with it while sitting there with the car running and sure enough the thermostat bounced all around. I plugged it back in firmly and the gauge in the car is been working normally since then. Thanks for your reply though.

mac25

Glad you have er running again =D.