Outback running hot

[coustanis]

Hi all.
I have an 04 Subbi Outback. Over the last few months I've noticed the
temp gauge almost at redline.
It used to run solid, right at the halfway point but now, somewhat
often I'll look at it and it's right at the beginning of redline.
Then, as I watch, it will slowly sink back to the halfway point. Then
this will repeat after a few minutes or so.

Any idea what this might be? Bad thermostat? Something else?

Thanks in advance.

 

[.._..]

Stuck thermostat? The Subby ones are a bit different than normal ones.

Have you checked the coolant level? Gotten it nice and hot and looked at
the overflow tank for bubbles? Checked the oil for milky appearance?

 

[Todd H.]

Hi all.
I have an 04 Subbi Outback. Over the last few months I've noticed the
temp gauge almost at redline.
It used to run solid, right at the halfway point but now, somewhat
often I'll look at it and it's right at the beginning of redline.
Then, as I watch, it will slowly sink back to the halfway point. Then
this will repeat after a few minutes or so.

Any idea what this might be? Bad thermostat? Something else?

Thanks in advance.

Head gaskets are a big problem on these, so that'd be my first worry.

Coolant level/appearance?

Ever had the radiator serviced, coolant replaced? If so recently did
the person doing it understand the rather specific burping procedure
involved with Subarus to ensure there is no air in the system?

Thermostat stuck closed would certainly be the happiest of scenarios.

Also, don't forget the "run the heater on full blast" trick to help
cool down your near-overheating engine. Remarkable how much it can
help reduce your blood pressure as the needle creeps up there.

Do get it into service asafp.

 

[Carl 1 Lucky Texan]

Hi all.
I have an 04 Subbi Outback. Over the last few months I've noticed the
temp gauge almost at redline.
It used to run solid, right at the halfway point but now, somewhat
often I'll look at it and it's right at the beginning of redline.
Then, as I watch, it will slowly sink back to the halfway point. Then
this will repeat after a few minutes or so.

Any idea what this might be? Bad thermostat? Something else?

Thanks in advance.

You say it sometimes cools back off. If it seems to begin creeping up at
stop lights, then go back down after the car has been movingfor ward for
a acoupla blocks - that would indicate the electric cooling fan is not
running.

As others have mentioned, some cars have finicky coolant re-fill
procedures or can have air entrained in the system if allowed to get low
on coolant. Bad thermostat, maybe even bad radiator cap are possible
culprits. And then we get to bad headgaskets.......

Carl

 

[hippo]

coustanis wrote:

You say it sometimes cools back off. If it seems to begin creeping up a

stop lights, then go back down after the car has been movingfor ward fo

a acoupla blocks - that would indicate the electric cooling fan is not
running.

As others have mentioned, some cars have finicky coolant re-fill
procedures or can have air entrained in the system if allowed to get lo

on coolant. Bad thermostat, maybe even bad radiator cap are possible
culprits. And then we get to bad headgaskets.......

Carl

All good posts but Carl's given you the cheapest/easiest first check. Nex
time it happens, pull over safely asap but while it's still showing ho
then open up and check that the fan is actually running. If not chec
fuse, sensor, fan and get it going again. Otherwise you just have to g
through the checklist of possibilities.

BTW, I'd find & fix it *soon* or else drive it minimally until you do
Cheers

 

[weelliott]

I had a problem with mine running hot only when I was driving with the
engine from about 2100 to 3200 RPM. Idling was not an issue. But if I
were donig about 55 mph or so, then it would start getting hot and
even got near the red zione a few times. To battle it I would
downshift to get the revs up and it would help. I thought it was the
ECU had messed up timing or something. I checked the coolant level and
all the things I could think of. I couldn't shake it. Then I changed
my oil, which I had neglected to do for about 6k miles. It ran so much
better after that. I'm not sure of the mechanism behind it, but I know
that hte oil change was the fix, because few months later when I was
up to about 5k miles on that oil it started running hot again. I
changed it, and all was better.

Then again our engines are different. I have the 2.2 liter in a 95
with over 200k miles.

 

[coustanis]

I had a problem with mine running hot only when I was driving with the
engine from about 2100 to 3200 RPM. Idling was not an issue. But if I
were donig about 55 mph or so, then it would start getting hot and
even got near the red zione a few times. To battle it I would
downshift to get the revs up and it would help. I thought it was the
ECU had messed up timing or something. I checked the coolant level and
all the things I could think of. I couldn't shake it. Then I changed
my oil, which I had neglected to do for about 6k miles. It ran so much
better after that. I'm not sure of the mechanism behind it, but I know
that hte oil change was the fix, because few months later when I was
up to about 5k miles on that oil it started running hot again. I
changed it, and all was better.

Then again our engines are different. I have the 2.2 liter in a 95
with over 200k miles.

Hi all again, OP here. The description from weelliott is the closest
to what is happening with mine.
I should have checked the obvious before posting here but I thought I
would wait for replies to come in as I
did the simple things.
Anyway, Oil level and appearance are good. I had just done an oil
change about 2200 miles ago.
No white froth on the stick.

The coolant level was low. I added a half gallon of coolant.
I used PEAK brand premixed 50/50.
Most went into the rad and some into the overflow res.
The problem only occurred to and from work as I drive the back roads,
averaging 40-50 mph at 2000-3000 rpm.
I won't be duplicating those conditions until Monday next.
I'd like to think it will solve the problem.

Does anyone know the burping procedure for this car as I haven't seen
a Chiltons or Haynes for this car.
May not be an issue but then again, it might.
Anyway, thanks for the replies and I'll post back in a few days with
the results, if anyone is interested.

 

[Mickey]

Hi all again, OP here. The description from weelliott is the closest
to what is happening with mine.
I should have checked the obvious before posting here but I thought I
would wait for replies to come in as I
did the simple things.
Anyway, Oil level and appearance are good. I had just done an oil
change about 2200 miles ago.
No white froth on the stick.

The coolant level was low. I added a half gallon of coolant.
I used PEAK brand premixed 50/50.
Most went into the rad and some into the overflow res.
The problem only occurred to and from work as I drive the back roads,
averaging 40-50 mph at 2000-3000 rpm.
I won't be duplicating those conditions until Monday next.
I'd like to think it will solve the problem.

Does anyone know the burping procedure for this car as I haven't seen
a Chiltons or Haynes for this car.
May not be an issue but then again, it might.
Anyway, thanks for the replies and I'll post back in a few days with
the results, if anyone is interested.

Here are a few comments based on my experience with my 00 OBW.

Your tstat could be starting to fail. Only replace with an OEM part.
3rd party parts may not have adequate flow. Found one high qlty 3rd
party part only had 60% as large of a water passage as OEM part.

Radiator has very small water passages. Easy to plug. Wouldn't
recommend any stop leak kind of product other than OEM that was
recommended as a stop gap measure for some models with head gasket problems.

Subie engines have the tendency to trap air in the block when coolant is
changed. This is due to the boxer design and fact the crossover pipe
between the left and right side in located mid-point and with engine
pointed slightly up at the front, air gets trapped in the left front.
Rad hose in on the right front so not a problem here. Don't have the
car up on ramps when trying to purge air from the cooling system.

I purge the air using the factory guide as the basis for what I do.
After filling the cooling system, I leave the rad cap off so no pressure
develops in the system. Start the engine and run it ~ 2k-2.5k rpm for

5 min. Time will vary on amb temp. You do need to make sure the tstat

is open and coolant is flowing throughout the system. I'd run the
engine for 5 min after you can feel hot water is flowing in the rad. I
next let the system to cool down, top up the rad if needed, reinstall
the cap and make sure the coolant overflow tank is about half full. I'D
watch the coolant level in the overflow tank for a couple days and make
sure it is kept are recommended level.

I used this procedure within the last couple weeks when I replaced the
antifreeze. No heating issue and only a small drop in coolant level in
the overflow tank after a couple days.