Engine getting warm

[immortal_suby]

I think it's the thermostat - but wanted to make sure.
Temperature climbing randomly (haven't seen a pattern), then before it gets more than 1/4" to below the red zone it drops back down quickly to normal. It will get warmer for a few minutes before it drops back.

Upper radiator hose hot and stiff during this.
Lower radiator hose only slightly warm.
Both fans working during this so I know it is not a temp sensor.

Local shop only had a thermostat and no gaskets. The T-stat didn't have the little bypass jiggle pin either - I think I'll order one straight from suby to be sure.

Anything else it could be?
I had the water pump replaced 100k ago as preventative maintenance.

[lee]

have you checked the level once cooled? I lost some coolant (I'm guessing from evaporation out of the overflow tank) and had an indicated temp problem at idle (sitting in line at a drive-thru). It was less than 2 quarts low - I'm wondering if the engine likes to form air bubbles with low coolant. Some years back a Fiat 124 Spyder (1600 engine) used to be prone to this behavior (wonder if Randy - svxeno - has ever had it happen to his 124).

[immortal_suby]

Coolant was a little low, but the overflow tank was full past the line.

[lee]

OK, my earlier is not so likely then. How about a faulty radiator cap, doesn't hold enough pressure?

BTW, I admit I have no knowledge of diagnostics steps, just trying to bounce some ideas that might help you.

[SVXRide]

Matt,
What kind of shape is your radiator in? Have you ever had it flushed? 200k + miles is a lot of miles on a radiator!
-Bill

[Subafreak]

Sounds kinda head gasketish to me. Does it build an unussual amout of pressure in the cooling system just after starting?

[immortal_suby]

Forgot to mention, radiator is new (well, new about a year ago)
Cap is also new - came with the radiator. I can swap caps with the wifes car though to check on it.

[immortal_suby]

Originally posted by Subafreak
Sounds kinda head gasketish to me. Does it build an unussual amout of pressure in the cooling system just after starting?

I wouldn't even know how to figure out if it did? What do I check for that.

[Subafreak]

When the car is cold (like first thing in the morning) Pop the hood and check the upper hose (it should be squishy) Then start up the car and wait a minuite or two and chech the stiffness of the upper hose. If it is already getting hard then you may have a blown head gasket. This may only work if it's leaking really well, to find a slower leak you can get a Headgasket Leak tester kit at NAPA for a few bucks, not sure how much but probly cheaper than taking it to a shop to have tested. Then again they might have a better idea of what there looking for.

I bet it is there thermostat....also make sure your coolong fans are working and that they BOTH are working.. Does the temp go up at stop lights? My 2 cents

Mike

[immortal_suby]

Cool - I'll check that in the morning.

Both fans work.
It doesn't do it all the time - I rarely ever see it really. It only does it if I have done alot of highway driving and then run into traffic. I don't think I have ever seen the temp go up in my normal 20 mile stop and go commute to work.

Dang, I hope it's not a headgasket. I've never done a headgasket on a suby.

[Subafreak]

Your first post is exactly the same problem we were having with an OB wagon. It didn't really seem like a headgasket at first so we put a T-stat in it. That didn't work so we went ahead and put a water pump in it. (along with a T-belt and front seal). Then I drove the thing home, 25miles, then almost back to work before it desided to overheat again. Then after a call to Subaru we did the headgaskets and finally fixed the problem. But when it overheated it would push most of the coolant into the overflow jug and the lower hose would be only warm.

I havn't really heard of SVX's having headgasket problems but it just sounds very similar to what I've seen.

[wawazat??]

Originally posted by Subafreak
Sounds kinda head gasketish to me.

Agreed Jesse.

What does your overflow bottle look like Matt? Clean or does it have some black gunk that smells nasty in it?

The headgasket job isn't that bad. I did mine just before I met you in Indy.

Todd

[immortal_suby]

Overflow bottle looks pretty clean - no oil or anything in there.
I never see any white smoke from the tailpipe. Ever.

I do have to add water - about a quart a week - to the radiator. I was hoping it was just going into the overflow and then splashing out during high risk maneuvers. Or maybe just boiling off since I don't have alot of coolant in the mix (turning into a southerner)

Does the engine need to be pulled to do a headgasket?

[wawazat??]

I'd recommend it Matt. I can't imagine trying to do it while it is in the car.



Todd