What is going on?

[subyguy522]

Picture this: I am driving down the road and look down at my gauges. I see that my engine temp gauge is in the red zone. I go a little further and it goes down to perfect temperature. Then I look about 3 minutes later and it is back up in the red zone, but again goes back down to the normal temp in a couple minutes. What is going on??

[sybir]

Best-case scenario, your thermostat is messed up.

Realistic scenario, your headgaskets (one or both) have failed.

Worst case scenario, your gaskets popped andcontinuing to drive on it caused the motor to overheat and warp the heads.

Look in your oil filler tube, is there white residue?
Look in your overflow tank, is there black residue?

I've popped mine twice now, with those same symptoms. :|

[Wiscon_Mark]

Your gugages could be messed up too, but I agree with Sybir's realstic scenario. If there's no oil in the coolant or other signs of HG failure, then replace the Thermostat.

[subyguy522]

I just checked my coolant and there is none in it!! I just filled it up a couple weeks ago because it was low. Does this help any? Maybe i have a coolant leak?

[gil_ong81]

check your oil.

[Bdubs]

If its fluctuating like that, I'd change the thermostat. When mine was on the fritz, it'd be fine one day, then the next it'd be in the red. Then the next day, it'd be normal.

[blackgtbeauty]

If its fluctuating like that, I'd change the thermostat. When mine was on the fritz, it'd be fine one day, then the next it'd be in the red. Then the next day, it'd be normal.

Yes a faulty thermostat would explain the fluctuating in the temp reading, but he's loosing coolant, it must be going somewhere, so my guess is headgasket, not thermostat.

[ivwarrior]

Sounds like it very well could be a head gasket (or both head gaskets). Check the oil, see if the level is way high and the oil looks like chocolate milk or something else screwy. If not, check under the car for visible signs of a coolant leak. If you can't find anything, get it to a garage and have them take a close look over the car.

[subyguy522]

Nothing is wrong with the oil. I'm in denile... i don't want it to be the head gaskets so I am doing a coolant flush and changing the thermostat and having my buddy who works at a dealership take a close look at it. If it is the head gaskets, i might be off the road for quite awhile. Thanks for all your help guys. Sybir was right on. I asked the subaru dealer and they prety much repeated what he said.

[Reason]

Don't you have the phase2 SOHC engine? I thought they don't blow headgaskets? or is all the 2.5 HG's are shit?

[Wiscon_Mark]

Don't you have the phase2 SOHC engine? I thought they don't blow headgaskets? or is all the 2.5 HG's are shit?

All cars have the potential to blow headgaskets.

The SOHCs have less of a chance, but still do sometimes. After 2004 Subaru REALLY addressed the issue.

[Plays_with_Toys]

Yeah there are still accounts of phase II EJ25's popping. Not as often, but they still do it.

[deadlydave]

I had the same thing happen--THE FUSES controlling the fans on my radiator were both blown. I replaced them, and the temp stabilized once I refilled the coolant.

[subyguy522]

Well... I changed the thermostat and flushed the coolant and put the coolant conditioner that subaru suggests to do to fix coolant leaks on phase 2 2.5L's. After all of that i realized I hadn't checked the fan fuses yet. My sub fan fuse WAS BLOWN! This still doesn't explain why coolant went missing though... hmm

[Plays_with_Toys]

When I forgot to plug my fans in my coolant boiled over and out. Might've happened to you as well and you just didn't notice. That would also imply you probably had/have an air pocket in the system.

[Wiscon_Mark]

When I forgot to plug my fans in my coolant boiled over and out. Might've happened to you as well and you just didn't notice. That would also imply you probably had/have an air pocket in the system.

Yep, the coolant will boil if you let it overheat.

[d1giPhux]

So did you get things fixed by changing the fuse? Hopefully.. but if not.. at least you got the coolant flushed and such! Hope things are working out okay for ya now!

[subyguy522]

Well, that is the same way i thought. I mean, I even changed my spark plugs while I was in there. So I not only changed the thermostat, but I also did the plugs, the coolant flush, and put the recommended subaru coolant conditioner that is suppose to eliminate the nororious popping gaskets on phase 2 2.5L engines. My car is running well, doesn't overheat, and doesn't seem to be loosing any coolant, but it is still under close watch.