Okay this is my stepdads car it is a 1997 legacy Brighton EJ22 213k

I have diagnosed the problem but I want your opinion. Here's what happened, we were driving down a dirt road that was fairly hilly and after a while the temp gauge started going up. The temp never got into the red zone so he kept driving it and when we got to level ground it cooled down a little to about half. then it started fluctuating up and down, by this time we were on the highway and we had the heater on full blast so I had my window open and I could here a squeaking, like an alternator belt but slower.

The heater would cool down whenever the engine Rpms slowed but would come back when engine Rpms were brought back up around 2500 Rpms. When we finally stopped and got out and checked it out I popped the cap off of the coolant resivour and it was full, there was no bubbles with the engine running. Also I felt the radiator and over 3/4 of the rad was cold top hose was hot and the bottom was cold.

This car has always ran just a little under halfway on the temp gauge since my stepdad first got it and it looks like the original radiator. He did have it flushed a couple months ago but it didn't change where the temp gauge sat.

 

This is what I believe happened. I think that it has a clogged radiator and when we started going up the steep hills it over heated enough to push some of the coolant out the resivour on to the timing belt covers (there was coolant on the TB covers) and some of it got on the timing belt making the water pump slip until we stopped and let it dry out.

 

I think we should change the radiator, coolant, oil, and inspect the timing belt/water pump. What do you think?

When was the water pump last replaced?

Thermostat?

T belt and idlers?

Upper hot and cold lower sounds (in this case) more like a sticking thermo or water pump starting to fail.

Mileage?

 

O.

Timing belt/water pump change is unknown. But I do know that the water pump is not leaking and since after it cooled off it started working again its not a spun impeller. The heat never shut off completely like a thermostat issue it actually was working well.

Mileage 213,000 give or take a few hundred miles.

IIRC Water pumps usually fail in two ways, they either leak or they spin the impeller.

Edit: also the differance in temps between hoses suggest a low flow problem that could be caused by multiple things. I believe it was caused by antifreeze contamination on the TB making it slip

Edited February 22, 201313 yr by mikaleda

Another thing I forgot to mention is I did inspect the timing belt a few months ago and it did look fairly new. If it was changed on schedual it should be about halfway through its life

Take it out on the highway. The faster you go the warmer the engine gets.  Cools right down as you slow down.  Classic symptoms for a faulty radiator.  With that mileage I'd replace the radiator first.  Easy to do yourself and only about $100 for the radiator.  After that you can look for other more expensive reasons, but I'd bet you'll have resolved the problem.

Edited February 23, 201313 yr by edrach

Take it out on the highway. The faster you go the warmer the engine gets.  Cools right down as you slow down.  Classic symptoms for a faulty radiator.  With that mileage I'd replace the radiator first.  Easy to do yourself and only about $100 for the radiator.  After that you can look for other more expensive reasons, but I'd bet you'll have resolved the problem.

That's exactly what I thought

The heater core is part of the bypass route on these which takes coolant from the crossover pipe on top of the block, through the core and then back down to the BACK side of the thermostat. When the thermostat is not open coolant is circulating through the heater core and block to prevent localized boiling of the coolant. The bypass route is also designed to bring warm coolant from the block around to the thermostat to keep it open in cold weather. With the thermostat on the inlet side of the water pump, coolant from the radiator can be cold enough to make the thermostat close, which blocks flow and causes further cooling in the radiator, while the coolant in the engine boils. The warm coolant coming through the bypass pipe is enough to keep the thermostat open.

 

Basically, you will still have heat even if the thermostat is closed. If you are unsure of how old the thermostat is replace it.

Edited February 23, 201313 yr by Fairtax4me

-

Edited February 23, 201313 yr by mikaleda

-

Edited February 23, 201313 yr by mikaleda

The heater core is part of the bypass route on these which takes coolant from the crossover pipe on top of the block, through the core and then back down to the BACK side of the thermostat. When the thermostat is not open coolant is circulating through the heater core and block to prevent localized boiling of the coolant. The bypass route is also designed to bring warm coolant from the block around to the thermostat to keep it open in cold weather. With the thermostat on the inlet side of the water pump, coolant from the radiator can be cold enough to make the thermostat close, which blocks flow and causes further cooling in the radiator, while the coolant in the engine boils. The warm coolant coming through the bypass pipe is enough to keep the thermostat open.

I'm not sure what you mean. I'm just guessing at this point but is that the reason for the fluctuation of temps after it overheated?

Well I'm not sure why that happened could someone please fix that^

Never mind I fixed it

Edited February 23, 201313 yr by mikaleda

Bump

go to test radiator in shop. If good.
try repair new thermostat $5dollar.
 ---if still overheating
water pump is bad bearing, or timing belt systems.

head gaket but doubtfully....

Okay I thought I would post an update my step dad decided to drive it as long as it is working normally again temp gauge still reads just below half but doesn't move on regular road driving it only seems to have a problem when it is being pushed hard. I am almost %100 sure of a bad radiator but its not my car so he is probably just going to drive it till it gives him problems again. I know it's not head gaskets yet, I know all about 2.2 head gasket leaks since I just got through this with my legacy.

Hello everyone, need some advice 97 subaru legacy outback 182k on it. overheating, justput new radiator and thermostat, refilled and fired up let run at idle until temperature came then held about 2000 rpm and temp started rising. Thinking it might be the water pump as upper is hot lower is cold. Just spent my last $14 on the thermostat.

Edited January 26, 201610 yr by Nomyar

Please, Nonyar, start a new thread.   

 

Hello everyone, need some advice 97 subaru legacy outback 182k on it. overheating, justput new radiator and thermostat, refilled and fired up let run at idle until temperature came then held about 2000 rpm and temp started rising. Thinking it might be the water pump as upper is hot lower is cold. Just spent my last $14 on the thermostat.

Search bleeding procedure and research