Car Overheats When Idling

Posted in Internal Engine Parts

Honda Civic 2003
In order to prepare for my drive from San Antonio, Tx to New York I had some maintenance done to my car. Ive had the car about three years and never had a problem with it.. NEVER. I requested a new water pump, timing belt and other belts replaced and thermostat. Couple weeks I began my drive to NY.

I noticed my car began to run warm. I needed gas so I pulled to get gas. When at idle it got much hotter. However when I pushed on the accelerator it began to cool down.

Made a stop in Okla (to visit family on the way to NY).. and had my dad take a look. We changed the thermostat, since it didnt look like it was changed. Then we drove the car and let it idle for approx 20 min to see if it would overheat… it didnt.

So I continued my drive to NY and noticed it running warm again when idling… but when driving it was fine.

I am now in NY and have noticed after a while of driving it will run warm at idle. Before this issue, the temp gauge was usually a bit under the half mark.

Any recommendations? I have about 111K on my car..
No leaks and fluid is fine… I do hear the fans come on but I will check them further. Yes its hot outside… but Ive moved from San Antonio, Tx to NY. It is A LOT cooler here! I have NEVER had a problem with this car within the 3 yrs Ive had it.

Thank you all very much for these recommendations :)

There are 8 Answers for "Car Overheats When Idling"

    1. O Werty O says:

      My Eclipse used to have the same problem! I took it to get repaired and I think he said it was a fluid leak that caused the computer in my car to think that it was overheating for some reason. I used to freak out while going through drive-thru’s because my heat gauge would be maxed out and I thought my car was gonna explode…lol. Your car is fine, you just need get the leak or problem fixed so the computer will register it correctly. Hope this helped!

    2. Jonathan W says:

      Check your fans, the fuses, and the relays. Usually, the fans pull air through the radiator when you’re stopped. When you get moving, the air will be pushed through there by the motion of the car. If a car only overheats at idle, then my first bet is the fans have failed in some way. Usually, there are more than one speed as well, so they may be stuck/failed in slow – a little harder to tell than being completely off/broken. Next check the water pump.

    3. Mastec 1970 says:

      1. Locate the cooling fan temperature switch on the thermostat housing. The thermostat housing is behind the distributor on the lower radiator hose.

      2. Unplug the connector on the temperature switch and jump the Green (GRN) wire to the Black (BLK) ground wire and verify the cooling fan runs. If the fan does not operate, check the relay, fuses and wire harness.

      3. If the cooling fan operates, verify the thermostat opens correctly and the radiator is not restricted. The temperature sensor needs to heat up to 194 degrees, then it should ground the GRN wire. If it does not, then the fan sensor is faulty.

    4. Audie Spell says:

      Your car has electric fans . One fan comes on and runs the entire time the a/c is turned on. The other fan soluld come on when the car gets above 195° . When your car is idleing check to see if the fans run after a bit. Check to see if the connections are good. Check the fan fuses. This should fix the problem.

    5. Pilsner Man says:

      It may be getting warm because it’s frikking hot! If it isn’t going close to the red zone, it’s OK. Make sure the fans are running at idle.

      And remember, it’s HOT!

    6. Salemcripple says:

      Are the fans comming on? Wait for the engine to warm up, check for twelve volts at the fan. Check for a good ground. If both are fine, then the fan needs to be replaced. If no voltage the most likely cause is the sending unit.

    7. Dan K says:

      Check > Fan, fluid level, thermostate

    8. Bandit_60 says:

      If the fan works then probably the radiator needs to be flushed out.