OK, I'm stumped...(97 Legacy Wagon overheating)

Did you fill the system with the nose up and heater on max? Could be a bubble in the cooling system. Though, of course, the 'bubble' could be exhaust gasses. Did the o'flow bottle - um - overflow itself? When the system cools off, does it draw back from the o'flow bottle? For a simple concept, there are multiple ways for a cooling system to 'go wrong'. If coolant mixed in with the water, AND coolant is sucked back from the o'flow when the engine cools off, probably the rad cap is OK. Is it new? How about the thermostat? Can you see bubbles in the neck if you run with the cap off idling? probably exhaust gasses.

Anyway - sounds like you definitley did not get water flowing through the heater core - so a plugged up radiator OR a gas bubble or a stucl thermostat are likley.

hmmm....

Carl

Sticking Thermostat? Not to say that's the only issue, but if it's not opening and the suddenly does it could explain the temperature spikes and the cold rad.

Thanks, cARL. yES, THE NOSE WAS IN THE AIR WHEN i FILLED THE SYSTEM (oops...) HEater on MAX, and there also seemed to be a bubble, but the STEAM coming out of a stone cold radiator is what's really puzzling...

I tried to get the bubbles out before I took off...ran it until the T-stat opened, and then added more, and then opened the bleeder.

I guess my $9 Headgasket repair, didn't...

So, I'm thinking, either new head gaskets (and plane the heads...?) or another new motor (supposedly this one has ~125,000 miles on it...)

It runs smooth, there is a very slight knocking noise sounding like in the center of the engine, very very slight.

The bosy has 335,000 on it, that's why I'm not putting a lot into it...

Hmmm Is the rad fan working(comes on when rad is hot)? Next thermostat, then water pump check them all.

I recall you posted months back that you have a subie that you want the fans not to work during winter season because the engine gets very cold. And you said you only used the subie during snow season. Is this the same car? The engine gets very cold in winter and overheats in warmer weather?

If you remove the radiator and take it to a radiator shop they can flow and pressure test it. It's not very expensive to have them do that.

Are you absolutely certain that the thermostat is installed correctly? Just a thought.

Only time I've had the cold radiator while heating up is with stuck radiator or frozen radiator hose. Other problem I just ran into that probably will be of no help. My son just returned my 97 Impreza because it was sporadically losing water and heating up. As it turned out, even with frequent anti freeze changes, something had eaten half of the surface where the radiator cap seals inside the plastic radiator. Outer seal (top of radiator) was fine. Should be a smooth continuous ring of plastic. I have repaired with JB weld (and let it cure at least a day) and is so far giving a good seal. In particular, the first hill would cause water to overflow and eventually would expel enough to cause overheating.

Only time I've had the cold radiator while heating up is with stuck thermostat or frozen radiator hose. Other problem I just ran into that probably will be of no help. My son just returned my 97 Impreza because it was sporadically losing water and heating up. As it turned out, even with frequent anti freeze changes, something had eaten half of the surface where the radiator cap seals inside the plastic radiator. Outer seal (top of radiator) was fine. Should be a smooth continuous ring of plastic. I have repaired with JB weld (and let it cure at least a day) and is so far giving a good seal. In particular, the first hill would cause water to overflow and eventually would expel enough to cause overheating.

Yeah, I believe so. But then again...

When I took the old one out, I saw how it had been installed, made a note, and put the new one back in.

But, the prior owner gave it to the guy that gave it to me cause it was overheating...

According to this, it's correct:

That would have been too simple, eh?

Yeah the fans are working. All the obvious stuff (er, I think!...) is OK.

New t-stat. Of course, that doesn't mean it's good, but it is new.

Nice try! But no, this is a different one. The one with the pump driven fan was the *OTHER* car I used the Genie in a Bottle stuff on, and that one's running great. i never did swap the fan over; I have one, but that car's coming off the road...since it's time...

There is a small heater hose under the throttle on the drivers side remove this small hose so it can bleed air remove the upper radiator hose from the rad & fill with coolant until coolant comes out of small hose then reinstall small hose & upper rad hose start engine up slowly add coolant this should remove any air bubble you might have Glenn K

Have you replaced the thermostat? Sounds like a problem I had many moons ago. Simple fix, if that's what it is.

If it's an autoparts store type they might have taken a short cut to make it cheaper. I've seen it before... sometimes it makes a difference. Although if there is a t-stat issue it's probably just a minor one making things worse.

I ain't that lucky...

What it appears to be is, not only do I have a blown headgasket, but perhaps the radiator is blocked, too...

It only overheats when it's under a load for a while. It will sit at idle or high idle for HOURS without overheating.

The problem is this:

and this:

Only one car can go on the road right now. Can you guess which one? ;)

I've read ALL of this thread - whew! Well, here's what happened to me years ago. I had a 1972 Corvette that had a VERY similar problem. After checking and double checking everything I could think of, I pulled the new waterpump I had installed a few weeks earlier. Turned out that the pump impeller was not tight on the shaft - the pulley was driving the pump impeller shaft as it should, but the impeller was only turning at, who knows, half speed? quarter speed? So especially at highway speeds or under load, it would overheat. At low load or idle, no problem. Well, there's my two cents worth.

Try flushing the radiator with sufficient pressure to unblock.