[jwhitehead]

Where do I start? I've been noticing for a while now that if I sit still for a while, like at a light or a drive through, the temp guage rises into the red sometimes. Sometimes it will go back down and others it won't go down until I start moving again. I have searched and found some threads but not quite with my problem.

I did notice that with the thermostat the guage will rise to about the 3/4 mark, for lack of a better term, and stabilize. I checked the old thermostat by submerging it in boiling water and could see it moving, so pretty sure that's not the cause. Both upper and lower hoses had pressure on them.

 

[ferret]

Since it does it when still, and goes away when driving, I would first see if the electric fans are coming on. Especially if the accessory belts or timing belt was recently changed, the fans removed and maybe not plugged in again.

After that, could be a circulation problem, thermostat, partially clogged radiator etc.

 

[4BangR]

You say "the old thermostat". Did you you replace the thermostat? If so, did you use an OEM part? Did you properly bleed the system of air?

To properly bleed the system you need to start the car and let it run until the thermostat opens. You can tell if its open if the top rubber coolant pipe is warm or hot. Take the radiator cap off and set a funnel in the radiator and poor some coolant into the radiator until it doesn't take any more. Now you will want to squeeze the pipe and watch the air bubbles pop up through the funnel. If it is taking coolant this is good. Keep a small amount of coolant in the funnel and keep squeezing the pipe, when the radiator will take no more coolant you are done.

If you replaced the thermostat with a regular auto parts store unit, replace with an OEM unit. The aftermarket thermostats are not even close to OEM size and they also don't have the little plunger.


If you already knew the above, then disregard:biggrin:

 

[jwhitehead]

The fans are running. Did replace the thermostat but not with original equipment but since the old one seems to work I may reinstall it. I did add coolant until it wouldn't take anymore, and when I squeezed the upper hose to expel the air coolant would gush out of the radiator. I'm not sure if there is an actual problem or if I'm losing my mind.

 

[Elmy]

Replace the rad cap just to have that done. It can cause alot of problems. :icon_eek:

 

[ferret]

This seems to be prevalent right now ... here's another post I just made regarding using a Subaru thermostat.

click on the link in the reply to see the difference between the Subaru thermostat and an aftermarket.

http://www.subaruforester.org/vbulletin/f88/2005-2-5x-suddenly-starts-overheating-76402/#post847756

 

[jwhitehead]

The cap is my next purchase.

 

[Elmy]

The cap is my next purchase.

Good. it's cheap anyway.

 

[jwhitehead]

OK, I am even more baffled than before. After some research I took my original factory t-stat and put it in a pot of water to check it. Works like it's supposed to. So I remove the aftermarket and put the original back in, while the engine was still warm. It seems like more coolant came out this time. Refill with coolant and run in the driveway for 30 minutes or so, no overheat. I drove down the road a bit, still fine. The fans didn't even come on, but I know they work. Drove to work today and temp is still fine, just below half. I'm losing my mind.