My car has been overheating while in traffic or while at a stoplight but when I'm actually driving the temp goes back to normal. And of course when I run my heater, the temp drops back to normal while It's sitting in idle. I have a 97 3.0 with roughly 180k miles. From what I saw on other posts, it's because the fan isn't running when it needs to be and it's probably the fan motor, radiator fan switch, fan timer, water pump, or t-stat. There are no leaks, majority of the heater hoses were replaced early last year. I changed the radiator fan switch to a mishimoto over the summer when I was having problems with the fan & it was ok until last month when it started overheating while idling again. Over the weekend, I changed the radiator fan w/ motor & it did it again when I drove it the next day. I noticed it doesn't overheat right away or even while taking short drives. It just happens after taking longer drives. I'm looking into maybe changing the radiator fan timer & see from there. Anyone else have any other suggestions?

 

Start simple may be air in the system. Try starting with the rad cap off and wait until the car warms up. Can also open the bleeder valve

 

Your thermostat is on the way out

 

I'll probably replace the radiator fan timer & the thermostat since I bought a mishimoto one last time when I thought my thermostat was bad.

 

So I had the system pressure tested and 1 of the cylinders isn't holding up which means it's the head gasket.

 

i second this motion.

 

So I had the head gasket fixed along with new thermostat & water pump but the car has been doing some weird stuff. First of all, it's still overheating in traffic & when I turn on the heater it goes back to normal. When I drove it yesterday the temp was fluctuating simultaneously while going between 20-30 on the street. I ran the car on idle for about almost 30 min with the radiator cap off & the heater on full blast to get all the air out & today it overheated in traffic again. I changed the thermostat to a mishimoto & the fan switch is also a mishimoto which was put in back in sept. Another weird thing it did was that it wouldn't start this morning. I put the key in, no accessories tuned on & no sound of it turning over. Checked the battery to see if it was connected & it was, tried starting it again & it started up normal but somehow the computer reset. Then this afternoon it wouldn't start again, this time with signs of a bad main relay. Then after about 10 min it started up normally. Help!!!

 

Make sure your engine block is clean, if it is gunked, or dusty it keeps more heat in your block and does not dissipate, these cars use air and coolant to help them from overheating.

 

look in the radiator reserve in front of the batery my tube fell off into it not aloowing it to get any antifreeze at all into the radiator/motor to cool it off. its a huge problem with our cars.

 

it may be the cooling fan relay fuse had that problem last summer