[bigjay]

On my way through the mountains last Friday, I noticed that on climbs my temp gauge would rise quickly to just below red from normal (normal = about half way up). I didn't think too much of it, as I had three adult passengers and about 200 lbs of extra gear in the trunk, on top of the engine revving high in 3rd to maintain 60-70 mph. On descents, the gauge would quickly drop back down to normal. The fluctuations were quick enough that I could watch the needle moving 1/3 of the way over a few seconds.

Today on the return trip, I noticed the same thing. This time though, I took it a little easier on climbs, and the gauge was staying consistently between 2/3 to red. I pulled over and smelled burning coolant under the hood, and noticed the reservoir had overflowed a little. After cooling a few minutes, the level was about an inch below the low line. I filled it to the low line and continued driving, taking it VERY slow over Vail Pass. I did get a little rise out of the gauge, but nothing much over 2/3. On the downhills, it returned to normal. Next time I stopped, the hot coolant was right at the full line. Driving on flat interstate back in the Foothills, the gauge was parked at normal for a good hour of 65-75 mph driving.

Are these fluctuations normal? I'm having flashbacks to the HG failure my MY98 Legacy suffered a couple months ago...when that happened, the gauge shot to max, and the car died upon stopping. My thoughts, from best case to worst case, are 1) imagination, 2) radiator cap not holding pressure, 3) coolant needs flushed, 4) thermostat, 5) water pump, 6) head gaskets. Any thoughts? (MY05 X, 71k miles, 4EAT)

 

[bigjay]

The more I think about this the more I think (hope?) it's a bad thermostat. It should take a few minutes for the temperature of the coolant to drop from redline to normal, right?

 

[Woody '04]

i don't think this overheating is normal. pretty good thoughts as to what might be wrong ...

do you keep an eye on your coolant tank?
how full was it before you started your trip?

was the cooling system partially or completely drained recently?

when was the last time the coolant was changed and flushed?
i would be thinking about flushing and new hoses and thermostat as preventive maintenance with the age and miles sometime in the next year anyway. (don't forget the 2 small ones for the throttle body in addition to the heater and radiator hoses).

you may have a slow leak in a coolant hose. check all the clamps, especially the upper radiator hose where it attaches to the engine cast tube. it will leak more than you think it would before actually seeing coolant there.

consider a cold pressure test of the cooling system. if it's a hose it should show up then. The equipment I have is a "tee" with a flare fitting to attach to the radiator with a piece of tubing and that has a tire valve for pressurizing with a bicycle pump (NOT air compressor) and a gauge to show the pressure (about 15 psi or so).

i have an '04 with 86k that's getting ready for HG due to external oil leak getting worse. i believe 2003 and up were more likely to have this condition than earlier models which had either internal coolant leaks (earliest) or external coolant leaks (interim). someone else here can probably fill in the exact years or post a thread link.?

 

[SonoranSubi]

No expert here. But I had a very similar problem under the same exact conditions on my 04 X. It just turned out to be a bad radiator cap.

 

[bigjay]

i don't think this overheating is normal. pretty good thoughts as to what might be wrong ...

do you keep an eye on your coolant tank?
how full was it before you started your trip?

was the cooling system partially or completely drained recently?

when was the last time the coolant was changed and flushed?
i would be thinking about flushing and new hoses and thermostat as preventive maintenance with the age and miles sometime in the next year anyway. (don't forget the 2 small ones for the throttle body in addition to the heater and radiator hoses).

you may have a slow leak in a coolant hose. check all the clamps, especially the upper radiator hose where it attaches to the engine cast tube. it will leak more than you think it would before actually seeing coolant there.

consider a cold pressure test of the cooling system. if it's a hose it should show up then. The equipment I have is a "tee" with a flare fitting to attach to the radiator with a piece of tubing and that has a tire valve for pressurizing with a bicycle pump (NOT air compressor) and a gauge to show the pressure (about 15 psi or so).

i have an '04 with 86k that's getting ready for HG due to external oil leak getting worse. i believe 2003 and up were more likely to have this condition than earlier models which had either internal coolant leaks (earliest) or external coolant leaks (interim). someone else here can probably fill in the exact years or post a thread link.?

I do keep a pretty good eye on the coolant. I checked just before leaving, and it was at the low fill line. I have no idea on the coolant flush/change history, as I just bought the car in late December. It's in the shop now...they're running a pressure test and may change out the thermostat. The tech is wary that it could be a HG (he said they see about 3-4 a week).

No expert here. But I had a very similar problem under the same exact conditions on my 04 X. It just turned out to be a bad radiator cap.

Cheers to hoping for this! I'll update once I get some results. Other thoughts are always appreciated.

 

[James]

I have experienced something similar with my old Car. That was when the coolant was low in the engine.

I think what is happening is the Thermostat reading the air vapor temperature. The air heats up really quickly then cools down really quickly when the fan kicks in, even if the actual liquid coolant temp is being maintained.

If I remember correctly I replaced the Radiator cap to fix the problem. Also check the level of the coolant in the Radiator (once the car has cooled down). You should be able to see the coolant level right near the top of the Rad. If you can not see the coolant try topping it up here, as well as the overflow. There should be very little air in the cooling system.

 

[bigjay]

I have experienced something similar with my old Car. That was when the coolant was low in the engine.

I think what is happening is the Thermostat reading the air vapor temperature. The air heats up really quickly then cools down really quickly when the fan kicks in, even if the actual liquid coolant temp is being maintained.

If I remember correctly I replaced the Radiator cap to fix the problem. Also check the level of the coolant in the Radiator (once the car has cooled down). You should be able to see the coolant level right near the top of the Rad. If you can not see the coolant try topping it up here, as well as the overflow. There should be very little air in the cooling system.

This seems very plausible. It's not like the engine block is heating up and cooling down within seconds, but the air in the headspace very well could (esp. when it's 10 degrees outside).

 

[techy101]

I had something similar, though probably not the same issue, in my SVX; but it took place on flat roads. Turned out to be an air bubble in the coolant/I didn't fill it correctly.

 

[bigjay]

Just got a call from the shop. They can see an external head gasket leak, a leak in the radiator, and leak in the thermostat housing. Even though it's 30k miles out, they're recommending a timing belt kit and water pump with no extra labor charge.

This isn't a dealership or a shop I've ever been to before, but I have received great reviews and referrals...they've been around for 35 years. They invited me to come down to the shop to visually see the leaks they're talking about. I'll probably still go to the dealership for a second opinion. Sucks that I just sold an Outback 2 months ago with blown HG's.

...$2800. :icon_frown:

Thoughts?

 

[guroove]

Skip the timing belt and water pump change, and that goes way down to ~ $300 + labor. IMO Radiators and thermostats are things that can be replaced in your driveway, but if you've never done work on your car, just let the dealer do it. This type of thing can be fixed for less than $300 if you do the work yourself.

 

[bigjay]

Skip the timing belt and water pump change, and that goes way down to ~ $300 + labor. IMO Radiators and thermostats are things that can be replaced in your driveway, but if you've never done work on your car, just let the dealer do it. This type of thing can be fixed for less than $300 if you do the work yourself.

Just got of the phone a Subaru service manager that I know...he agreed that the timing belt swap would save me a chunk of labor down the road. He thought I could skip the water pump. I wish I could do the labor myself, but I'm not to that point yet.

 

[Woody '04]

that amount of $ is not terribly bad for all that stuff.
if you go "all the way" on repairs also consider oil pump re-seal with o-ring too.

how good is it running now otherwise and how long do you want to keep the car? maybe consider a compression test to help determine engine condition before all the work?

i still wonder about the air bubble or slow coolant loss through hose(s) scenarios (maybe in combination with leaky radiator cap). unless the HG leak looks dire, I would keep close eye on radiator and overflow tank for a week or 2 and see how it goes with coolant levels and any overheating.

did they say if your HG leak is coolant or oil? and just external or internal too?

HG leaks can be unpredictable. I had small "seeps" on past 2000s involving both coolant and oil as near as I could determine. I change my own oil and cleaned the heads between changes. The first was totaled 120kmi and the second traded 135kmi before they got bad enough to be necessary to do HG.

now i have '04 that oil leak is bad enough to do HG at 86kmi (don't want to smell it on the exhaust). :icon_frown:

 

[bigjay]

that amount of $ is not terribly bad for all that stuff.
if you go "all the way" on repairs also consider oil pump re-seal with o-ring too.

how good is it running now otherwise and how long do you want to keep the car? maybe consider a compression test to help determine engine condition before all the work?

i still wonder about the air bubble or slow coolant loss through hose(s) scenarios (maybe in combination with leaky radiator cap). unless the HG leak looks dire, I would keep close eye on radiator and overflow tank for a week or 2 and see how it goes with coolant levels and any overheating.

did they say if your HG leak is coolant or oil? and just external or internal too?

HG leaks can be unpredictable. I had small "seeps" on past 2000s involving both coolant and oil as near as I could determine. I change my own oil and cleaned the heads between changes. The first was totaled 120kmi and the second traded 135kmi before they got bad enough to be necessary to do HG.

now i have '04 that oil leak is bad enough to do HG at 86kmi (don't want to smell it on the exhaust). :icon_frown:

I'd like to see this car hit 200,000 miles, so many, many more years of driving. The shop said they'd do a compression test at half price for me ($60ish) before doing the work, if I want that peace of mind. They said the radiator leak isn't that common, but could have been caused by overheating. The HG leak is an external oil leak. I took a look at it under the lift and could see the oil is weeping out where the head and block meet...they didn't recommend waiting long to get it fixed.

If I go with this shop, all parts are non-OEM (although they will put in OEM if I insist). Minimum warranty is 24k or 24 months on all parts, and some are lifetime. Should I insist on all OEM parts? He said they've had great track records with all the aftermarket parts they use. That said, the car is at the dealership now for a second opinion.

Thanks for all the advice!

 

[neoshi]

Ask them what exactly is aftermarket and what isn't. For things like headgaskets, people seem to have better luck with aftermarket than OEM. On my car, all my modded pieces (suspension) are doing better than my unmodded (drivetrain and brakes) (>_<)

 

[bigjay]

Ask them what exactly is aftermarket and what isn't. For things like headgaskets, people seem to have better luck with aftermarket than OEM. On my car, all my modded pieces (suspension) are doing better than my unmodded (drivetrain and brakes) (>_<)

I don't think ANY of the quoted parts are OEM. The thing I'm most concerned with is the timing belt...I've been told before to only get a genuine Subaru belt. All of the pulleys are included in the quote...

 

[funkymonkey1002]

I'd go in and see where the leaks are and post pics here if possible. A seeping external headgasket leak isn't terrible, you could probably put that off for a while unless its bad, and then get it done when you would have done the timing belt etc.

I'd probably just replace the radiator and t-stat and makesure everythings sealed properly.

The only non-oem timing belt I would use is the Gates belt, as they're good quality and make a lot of OEM parts.

 

[Woody '04]

I'd like to see this car hit 200,000 miles, so many, many more years of driving. The shop said they'd do a compression test at half price for me ($60ish) before doing the work, if I want that peace of mind. They said the radiator leak isn't that common, but could have been caused by overheating. The HG leak is an external oil leak. I took a look at it under the lift and could see the oil is weeping out where the head and block meet...they didn't recommend waiting long to get it fixed.

If I go with this shop, all parts are non-OEM (although they will put in OEM if I insist). Minimum warranty is 24k or 24 months on all parts, and some are lifetime. Should I insist on all OEM parts? He said they've had great track records with all the aftermarket parts they use. That said, the car is at the dealership now for a second opinion.

Thanks for all the advice!

For that $ the parts should be OEM, and I would go with OEM timing belt.

So far my experience with Subaru Forester parts is they aren't as predictable $ as with Toyotas. Sometimes OEM parts are cheaper, sometimes only maybe 20% more and sometimes astronomical. Most of the OEM parts for HG and timing job shouldn't be much more than aftermarket. For parts for these jobs I would use "better" aftermarket parts if not using OEM. Like Car Quest or Napa instead of Advance or Autozone.

I tried aftermarket valve cover gaskets and washers on the first one I had and they just didn't seem to seal as good as OEM.

The shop I have lined up to do my HG said OEM is now multi-layer shim (MLS) design that should work better and longer than the one that came on the car. If I didn't have the extra warranty I might try to squeeze some months out of it and plan on renting a car for any long trips.

Best wishes and good luck on your decisions.

 

[bigjay]

Dealership replaced the radiator cap and said the car is good to go. They didn't notice an external HG oil leak. Arg...I want to believe this is it, but I saw the oil leak.

Will take and post pictures once I get the car back. In theory, is this something I can drive with for a while as long as keep an eye on the leak and temp gauge?

 

[Woody '04]

Dealership replaced the radiator cap and said the car is good to go. They didn't notice an external HG oil leak. Arg...I want to believe this is it, but I saw the oil leak.

Will take and post pictures once I get the car back. In theory, is this something I can drive with for a while as long as keep an eye on the leak and temp gauge?

If the oil leak goes too bad too fast it should start stinking from oil getting onto hot exhaust. Keep an eye on it and check oil level more frequently. I have no idea the likelihood of sudden failure; it seems remote but possible. And remember if you ever see the oil pressure light, seconds count in getting the car shut off and avoiding or minimizing damage.