Temp Fluxuation
 

Ok, So I seem to be having the same problem as DearPrudence. Every now and again the temp will shoot up to the top of the temp symbol and will cool off. Car seems normal as far as "under the hood temp feel" is concerned. It won't do this multiple times, just once a day, for now...(crosses fingers)

Would a flush do the trick, or am I in some serious pocketbook trouble. The temps here in Idaho are getting pretty close to the century mark and having owned my baby since December 31st 2003 am in limbo about what is wrong. When I bought the car the guy I bought it from said that it was a newer engine with about 40k on it, and no paperwork to tell for sure. Did I get handled or is this just a simple fix.

Please help...

Keith

Honestly, I would at least talk to a radiator shop. It could be something as simple as a flush, but could be a bad sign of a head gasket leak. Many competent shops can take a quick look at the symptoms and give an adequate diagnosis.

I would have the radiator inspected, flushed, and rotted out by a radiator shop, check the engine codes to see if anything is wrong with the coolant temperature sensor (and possibly other things), then change the thermostat and t-stat housing gasket. Inspect all radiator lines as well. Be sure that a precise 50/50 mixture is achieved when the radiator is refilled (Prestone sells a very cheap tester).

I recently went through the whole coolant problem fiasco with my car, and things seem to be on the up now (knocks on wood). Good luck.

If you're not losing coolant, it's very, very unlikely to be the head gasket. And you probably don't need a cooling system flush unless sombody's been running straight stop leak.

My old Legacy had precisely the same symptoms. Thermostat. Honest. Change it before you spend a dime on anything else.


dcb

I am not losing any coolant and am hoping that it is just the thermostat and radiator that needs flushed.

Keith

This sounds exactly like a worn-out thermostat. Replace it and I bet you're good to go.

Yippie!!! How hard is it to replace by my self and how much for the thermostat?

Keith

Easy to replace and $9.33 from subaruparts.com

Reference link

Mine came with a gasket. Not sure if they all do.

Just a little more interesting info. The only time that the temp really soars is when the fans kick on while parked and idling. hmmm...

Keith

I'm not certain, but it's possible that the fans are kicking on because the temperature has spiked. I think it's possible that you don't see that until after the fans kick on becasue the ECU and the water temp gauge use different sensors.

Or there's a better answer. I don't know. I'd still replace the thermostat before looking at anything else. It'll give you a chance to drain and refill your coolant anyway. :)

3.99 for a 170 thermostat from autozone doesn't sound like it will do the trick, does it. I'll have to make it to Tom Scott Subaru Monday and see how much they charge for an OEM thermo.

Keith

Do not get any parts store thermostat. They will sell you a tiny little piece of junk. The stock thermostat is a pretty large unit.

I had the exact same thing happen
 

Mine would do that as well. It started just like yours then evolved to getting hot anytime the car sat still for a few minutes, but would cool off after i got under way. I too asked the yahoo club and they said thermostat so i replaced that and did a flush too but it didn't help. Turned out that my water pump was going bad. Have you ever replaced the water pump? How many miles do you have on it?

~Ray

Mine is from Fisher Auto Parts and I have not had a problem. It was a little beefier then the one that came out. I also replaced the water pump at the same time. It too came from Fisher Auto Parts.
Water pump removed with out removing t-belt gear

Steve

Well, I checked the fluid again and it was low. Filled it up and didn't see much temp change all night. Funny thing is that I haven't seen any leekage what so ever. Could it be evaporation caused by the temp and my driving habits?

Keith

I'd be worried about the headgasket. The fluid can be leaking through the exhaust.