Wifes car is overheating. Why?

So my wifes car is heating up when stopped at a light or in traffic. No problems with the engine output or shutting off but I notice the temp gauge climbing to H. Once the car begans moving the temp drops. Car has 130,000 miles. Whats up with it?

 

Its a 2001 Dodge Stratus. The cooling fans work and the coolant level is full and brand new

 

I've seen people put thermostats in upside down before... Same symptoms. Turn the heater on when you stop and see what it does.

 

no just the coolant got flushed

 

X1 Check the thermostat

 

What should happen with the heater?

 

If it does not overheat at highway speeds, but overheats sitting still or at low speeds like below 30 mph, I think immediately of airflow issues.

You said the fans are working. Let me tell you something we experienced with a 2001 Jeep Grand Cherokee (chrysler product so it may be similar). The Jeep had it's cooling fan stick on with the vehicle off. It was taken to a mechanic after I could not find the cooling fan relay under the hood.
Turns out that the "relay" is actually a variable speed control box mounted behind the front bumper cover. The mechanic who changed the "relay" said he had another Jeep that had the fans not come on at all and the vehicle overheated.

It may be possible you have the same fan control on your car. Could be that it has failed and is only running the fans at low speed. I believe these variable speed controls use PWM (pulse width modulation) which is just rapid on-off switching if I remember correctly. So I don't think you can check for full speed with just a voltage reading at the fan motor. You would need to measure frequency and know what that frequency is supposed to be.

Same Jeep I was talking about actually had a radiator and thermostat put in it a couple years later because it was overheating in 110 degree heat. At that point it was overheating on the highway, sitting still, whatever, made no difference.

I still think you have an airflow issue. If it were me I would hotwire the fans to direct 12 volts from the battery and see if it stops overheating. But I have never actually done it, and I can't guarentee that you won't damage anything by doing so.

 

Maybe the fan clutch is gone?

 

Heater on high should make the temp drop by acting as an extra radiator with it's own fan as well. If the thermostat is bad, I would think that it would still overheat with the heater on. I know from experience that a bad engine fan or radiator can be partially compensated for by running the heater.

 

The radiator may have one or more cores plugged. Take it to a radiator shop and have them check it out. I would pluck down 6 bucks on a thermostat first though.

 

its a dodge. trade it in for a honda, problem solved.

 

The heater should make the thermostat open up. My old truck used to overheat and everytime I would stop I cranked the heater wide open so I wouldnt have a bobo... Then it froze and I cracked the head lol I thought you were saying the the thermostat was new that is why I said it may be upside down but scratch that.

 

If it's only overheating at a stop, my money is on one or both of the cooling fans.

 

If it does not puke out fluid it may not hurt anything.

Look for the obvious, if they flushed the system look at anything they may have touched.
If it does overheat and dumps fluid shut it off before it destroys head gaskets or heads.

Definatly run the weater to circulate the fluid in case it air locked and did not get replaced when they flushed it.

Do not open the system ( radiator cap ) when hot it will burn the crap out of you.
You can open the fill tank usually plastic to check level.

 

*leaving now*

 

Might as well change the thermostat. It's a few dollars and only takes a few minutes to replace, usually. Same deal happened to my old Accord and my girlfriend's old Grand Prix. Thermostat fixed it both times. If it doesn't fix it for you, you're only out a couple dollars and a few minutes of time.

 

first off its a dodge. There known for just stop working. There should be bleeder valve for the coolant..Crack it open and see if any air comes out while the car is running(you said you just had a coolant flush done?) If not, then move onto the Tstat. Lots of times, there easier to say "ill do it" then when you get into it and everything freaking brakes.

 

Our Camry did this too. Replaced the thermostat and problem was gone. Took like 10 minutes to do too.