I have 2003 Baja. It has started running hot when the AC is on and the Baja is not moving. It does not run hot every time I stop, just a couple time a week. It will run hot after idling for a few minutes. I have checked and both cooling fans are working. When it run hot I start driving and with-in 1/4 miles the temp returns back to normal. Any suggestion to what could be wrong?

air in the coolant system perhaps did you just have any service done?

or the HG has gone.

 

what are the outside temps, desert?

miles on your Baja.

I believe your engine is the later EJ25 that will develop external head gasket leaks. Crawl under and see if you see coolant leaking from the cylinder heads.

If it only runs hot when the AC is on...my bet is a stuck thermostat or a clogged radiator or air in the system... OR is it running hot all the time?As mentioned though if you can pop under the car and see if you notice any seepage coming off of (usually) the drivers side HG/ steering rack boot area that would help us shed a little more light on the situation... we must def. not overlook the basics...Is the radiator/overflow full of coolant? How many miles are on the vehicle? Has the cooling system been serviced recently? You say the cooling fans are working...so they are both cycling on and off?

I would be surprised if this was your problem but...

 

On my 2001 Outback Wagon, I had a very similar problem. My temp gauge would shoot up if I had the A/C on, but was not moving. If the car was moving then no problem. There were no coolant leaks and I had just had new head gaskets installed at the local Subaru dealer about 6 months prior.

 

I kept thinking about the symptoms and it almost seemed like the cooling fan was running in reverse, throwing hot air from the radiator onto the A/C condenser, but I thought how could that possibly happen when it used to work fine. So one hot day when I got home and with the A/C still running, I got out of the car and walked to the front of the car. Surprisingly, there was hot air blowing OUT of the front of the car !! I opened the hood and waited for the fan to cycle off so I could see which direction it was turning. It was running in reverse !!!!

 

I don't think there is any possible explanation for it other than one of the shops that I took it to reversed the wires in hopes of generating a future service call.

 

I reversed the wires and then the A/C and temp gauge were fine.

 

If there is some other electrical anomaly that could cause this, then you may want to check to see what your fan is doing when the A/C is on.

I would be surprised if this was your problem but...

 

On my 2001 Outback Wagon, I had a very similar problem. My temp gauge would shoot up if I had the A/C on, but was not moving. If the car was moving then no problem. There were no coolant leaks and I had just had new head gaskets installed at the local Subaru dealer about 6 months prior.

 

I kept thinking about the symptoms and it almost seemed like the cooling fan was running in reverse, throwing hot air from the radiator onto the A/C condenser, but I thought how could that possibly happen when it used to work fine. So one hot day when I got home and with the A/C still running, I got out of the car and walked to the front of the car. Surprisingly, there was hot air blowing OUT of the front of the car !! I opened the hood and waited for the fan to cycle off so I could see which direction it was turning. It was running in reverse !!!!

 

I don't think there is any possible explanation for it other than one of the shops that I took it to reversed the wires in hopes of generating a future service call.

 

I reversed the wires and then the A/C and temp gauge were fine.

 

If there is some other electrical anomaly that could cause this, then you may want to check to see what your fan is doing when the A/C is on.

 

Wow!...That is a first in my book...I have never heard of this...