Another overheating thread

Black88GTA · #1 03-07-2010, 05:09 PM

I was out driving today, (about 50 degrees, sunny) and got stuck in traffic. Everything seemed OK, until I looked at the temp gauge, and it was at 3/4 of the way up

So I pulled over as fast as I could, and took a look at things. Here's what I found...

Both fans were on, and working normally.
Overflow tank was beyond the full mark, but not bubbling / boiling or anything. In fact, I dipped my finger in it, and it was barely warm.
Radiator cap / top of radiator felt warm (not hot)
I could put my hand on the intake manifold with the car running and leave it there (warm, not hot)
Upper radiator hose was warm
Oil on dipstick / under cap looked fine
No leaks at all.

So, I allowed it to cool down for a few minutes, then decided to turn back and drive it home (with an eye on the temp gauge, and the heat on full). I noticed that when I was idling / moving slowly, the temp would go up. But at expressway speeds, it dropped to normal operating temp and stayed there (never went below normal). The car drove fine - I wouldn't have even known anything was amiss unless I looked at the temp gauge.

The radiator was replaced last summer with a new one. Water pump / thermostat are unknown age / mileage. Although I would guess that the thermostat is probably OK, since the temp never went below normal when I was on the expressway.

Does anyone know what this might be? I'm suspecting either the head gasket, or water pump. God I hope it isn't the head gasket. I have no idea how I'm going to fix that here if it is.

redlightningsvx · #2 03-07-2010, 06:31 PM

I had the exact same thing and I replaced the T-stat and rad cap with new OEM parts and it never happened again. It would be 3/4 the way up and only raise at lower speeds but faster speeds it went to normal. My old T-stat that was 2 weeks old from Subaru would only open so much, and not full at temp. Also the rad cap 2 weeks old was junk from Subaru. Here's the thread...http://www.subaru-svx.net/forum/showthread.php?t=51144

immortal_suby · #3 03-07-2010, 06:59 PM

cheapest thing to do is replace the t-stat and rad cap and cross your fingers hoping it's not a head gasket.

sabin · #4 03-07-2010, 10:32 PM

i have a brand new rad cap if you want it

Black88GTA · #5 03-07-2010, 11:15 PM

Thanks for the replies, everyone. I went out just now and looked at it again after it had cooled down completely. I fear the worst.

No coolant is visible in the radiator, but the overflow tank remains nearly full, even after fully cooling down.

I blew through the hose connecting the overflow tank to the radiator - seemed a bit tough to blow through at first, but it's fine now. I sniffed the radiator fill neck with the cap off, and it smells like exhaust. As far as I know, the only thing that can make your coolant smell like exhaust is either a bad HG or cracked head / block. So, I think it's done.

I guess now I'll have to either read up on how to change a head gasket, or bend over and pay someone to do it / help me do it that isn't too far away. At least it got me through winter, I guess.

sowise · #6 03-08-2010, 05:11 AM

Here is a suggestion on something to consider...

Pay someone to do it could cost about $2000 +

You can buy general tool set (craftsman at any sears) expensive side would be say $169
Harbor freight engine lift $180-250
harbor freight engine stand $50-60
Dealer engine reseal kit I can't remember the exact cost but atleast $250 add in lets say another 150 for misc. sensors or hoses etc.

DIY Low side $799 (and not all spent at once either) high side $879.

You keep all the tools or resell what you don't want. See paying someone else just doesn't make much sense to me. If you have some mechanical experience, a manual (yeh even chiltons), and the forums you should be able to do pretty much anything to these cars. Just my $0.02