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2001 Subaru Overheat Challenge (and's not the head gasket!)

First off, if anyone can figure this one out, dinner is on me next time you’re in Cheyenne Wyoming!

OK guys, I’ve got a good one. Hope you’re comfy and you have some coffee.

We purchased a 2001 Forester with about 70k miles on it last year. Driven by a couple in their 70s and oil changed at the dealer every 3,000 miles so we figured it was worth risking the head gasket issue. WRONG.

After about 6 months of worry-free driving, it started overheating on the highway only (after about 60 minutes at 70+ mph) so we took it in, telling the dealer we were worried about the head gasket. They said no, it’s the water pump. So we had them put in a new water pump and timing belt.

Upon receipt of the car, it was still overheating, so we took it back. We mentioned the head gasket again, but they said no, it’s the temp sending unit. New temp sending unit, and guess what, still overheating.

The third time they changed the head gasket. After some debate, they charged us for parts only. Well, it still overheated.

So they found a crack in the radiator, and put a new one on. Still overheats.

So they sent the heads off to have them inspected for warping and cracks. The heads came back clean.

Next step, the block! They installed a new block and it STILL OVERHEATS.

The dealership has provided us a rental car for the past couple of weeks, as we are now 7 (seven!) months into this process. Anyone have any ideas what the problem could be?

Thanks for volunteering your help guys!

I’m having a difficult time seeing this car having this many major problems on a car with only 70k miles on it and factoring in the previous owners. Offhand, it sounds like someone has been doing a lot of WAGing at your expense

What are the symptoms behind this overheat problem? Is there coolant loss, temp gauge pegged on HOT, steaming, and so on.
Are the radiator fans running when the A/C is on and does one cycle on and off even with the A/C off? Does the engine run fine at highway speeds other than the overheating issue?
Pardon the questions but they’re critical to making a guess; either wild or half educated.

The part about changing head gaskets and and later on apparently tearing it all apart to check the heads for flatness sounds pretty ominous to me. Checking the heads is part and parcel of any head gasket job and should have been done the first time.

OT I know, but from your ID should I gather that you’re a Hercules pilot? I’m a raging aircraft fan and the C130 is lights out cool in my opinion.

(Though you haven’t mentioned the model no.) I was leaning at OK"s above post and it seems that the only thing you didn’t mention was the cooling fans.

Second thing is why in H would they give you back your car knowing it was still overheating?

It is possible that the previous owners got that head gasket sealer fix / factory and some clogged up the rad. Which leads me to believe that maybe they didn’t put a new radiator in just had a recon job that wasn’t properly tested.

It’s time to get tough! You call them and say you have till 5 p.m. to have that car running without over heating. You don’t pay for the rental car and you find out exactly what was the problem and only pay for that. Or simply take the car right off the lot to another mechanic and have them fix it. Regardless it’s small claims court and the judge will go with your side. There are only a few things that will make it overheat and I’m sure they know what it is.

Who has been paying for these ‘repairs’?
If you have been paying for them, I bet they won’t find it for at least another $4000.

I don’t see a thermostat mentioned. I’ve had them be bad right out of the box. Do you suppose it could be something that obvious?

Obfuscation: Strange but true, I ran onto one once where some previous mechanic had crammed a red shop rag into the lower radiator hose to keep it from dripping during a radiator removal. Then he stuck the hose back onto the radiator. Under suction from the pump, it would seep just enough coolant to cool at low speeds. On the highway it would overheat in a mile.

Of course you got six months of good service out of your Subaru, so that can’t be your issue.

It seems to me that they have replaced almost EVERYTHING having to do with the cooling of the car. Except as others have stated the fans. If they are running at highway speeds I have been told they can act like a wall and actually restrict airflow…

Also I assume this car has some kind of air dam that funnels air into the radiator while at speed (most cars do), is it possible this dam is missing or broken (it’s usually plastic)…

Lastly has any one checked the radiator cap, or replaced it? A coolant system not holding pressure can cause a highway run hot situation. Which leads me to the hoses, has any one checked or replaced the clamps (again they may be fine at idle, but at high speed high pressure may leak just enough to vent the pressure from the coolant system). At this point it we are all just guessing, as your problem is so very strange.

I wonder whether it is really overheating. If he’s going by the dash gauge only, how do you know it is telling you the truth? Had the coolant temperature been measured independently?
It coolant leaking out or boiling over?

The first thing to do whenever confronted with an odd and potentially expensive problem is to verify the data you’re making the decisions on. Why do you think the engine is overheating? Have you checked to be sure the engine temperature sensor is accurate?

Wow, thanks for all the responses guys. First off, I mistyped! It’s a 2005 Forester. Kind of a big difference…sorry about that one.

ok4450: a lot of WAGing is probably an accurate assessment. Here are some symptoms…at first when the car overheated it smelled strongly of antifreeze after you stopped and exited the car. No smell on the inside. Now there’s no smell at all. There was coolant loss at first, associated with the overheats, none on the ground. It’s been at the dealer so long that I don’t know if it’s still doing that. Here’s how the overheat happens. The temp gauge goes to horizontal (where it’s supposed to be) within a few minutes after starting the car. At speeds less than around 50mph it will stay there for a long time, around 45 minutes. At 70mph it rises quickly to the red zone and keeps rising. I’ve always managed to pull over within 1-2 minutes of it hitting red. After pulling over and lifting the hood for a while, I’ll start the car, drive a few feet, and the temp will rapidly drop to midway between normal and hot. If I keep driving it will work its way to the hot range.
The engine does run fine at highway speeds other than the overheat. I haven’t looked at the radiator fans closely other than to note that they are turning when the car is idling. They will continue turning if I leave the key in the “on” position with the engine off and hot.
BTW, yep the herk is a pretty cool plane to fly. I’m lucky enough to still look forward to going to work every day!

binkman: 2005 Forester 2.5xt. Manual tranny base model. The reason they keep giving the car back is that they drive it around 3 miles (from the odo reading) and it doesn’t overheat, so they just assume it’s good without taking it on the highway for any length of time. Trust me, the only reason it’s still there is that they’re doing things for free now, and they’re paying for the rental car. I will never take a car there again after this boondoggle is over.

MG: I will call tomorrow and talk to them about the thermostat. If it’s that I’m not sure if I’ll laugh or cry. Funny enough, I did mention to them that something could be clogging one of the hoses, but got shrugged off. I will reattack on that point.

ragtop: interesting ideas about the highway-speed aspect of the problem! I’ll take your advice straight to the mechanic and ask him point-blank about the clamps.

Remco: No coolant leak, no boil over. I’ve tried to not let it get to a full blown overheat. The dealer tells me they’ve confirmed that it is actually overheating. I will ask again though to be sure.

Mtraveler: same as Remco, I’ll bug them again and verify that they’ve actually checked.

You guys are super helpful! I will keep you all posted and let you know what happens as the situation develops.

Has the shop not consider the possibility of a failing thermostat? Maybe when the engine is heating up the T-stat is trying to close back up. In turn, this will cause overheating and possibly coolant being discharged into the overflow bottle when the radiator pressure cap gives up.

A weak radiator cap can also cause a problem like this but (in my opinion) a thermostat is a regular maintenance item that should be changed every 3 or 4 years as a precaution. I’ve always recommended and changed them as part of a head gasket job also. Many an engine has been fried because of that inexpensive little part.

I suppose they won’t let you drive the Hercules home… :slight_smile:

(I’ve gotten to see half a dozen C130 demostrations and the plane just amazes me at how fast it gets off the ground and gains altitude even without JATO assist. I did get to see one with the bottles though! There’s a few come in and out to the base here now and then but they’re generally the electronic warfare variant; the Compass Call I think it is.)

I might add this. Other than the iffy thermostat part of this problem it could be that an iffy radiator pressure cap could be releasing due to slightly elevated engine temps from the higher speed. A cap can be pressure tested just like a radiator but often it’s easier to just replace it.

Another possibility might be this; and it ties in with the cap. Maybe the car has a partially clogged catalytic converter. This could allow the car to run in an apparently normal condition but with elevated speeds maybe the exhaust is building up enough back pressure to cause overheating which in turn will cause the radiator cap to pop off and release some of the pressure. That could explain some of the coolant smell.

A severe clog in a converter can even cause the header pipes to glow red but a partial clog will not.
The best way to check for a converter clog is with a vacuum gauge; assuming you can find someone who uses one and understands it.

The vacuum gauge can exhibit readings that are different based on how severe any clog is.
One is that the needle will drop to zero and slowly return to the at-idle reading and that denotes a severe clog. This is not likely because your car appears to run fine.
Two is that the needle will drop to zero and return to an above normal reading before slowly dropping to normal again. This could mean the partial clog I’m referring to.

I keep thinking that the problem with your car is that the problem was overthought from the start with someone not seeing the forest for the trees so to speak. Hope that helps in this endeavor and good luck.

Quoting @OK4450 "(I’ve gotten to see half a dozen C130 demostrations and the plane just amazes me at how fast it gets off the ground and gains altitude even without JATO assist. I did get to see one with the bottles though! There’s a few come in and out to the base here now and then but they’re generally the electronic warfare variant; the Compass Call I think it is.) "

If you like the C-130, have you seen the C-17 in action? The video here shows one that landed at the wrong airport near Tampa FL. If you watch it all, it shows it taking off from the 3400’ runway. I saw it on the news the evening it happened. The guys with me were saying it’ll never make it. I said it would be no sweat. The C-17 was designed as a STOL (Short Take Off & Landing) aircraft. See also

Any pilot who says he’s never landed, or at least lined up on final approach, at the wrong airport either has not flown much, or he’s a liar. I got it over early, 1200 miles from home, two weeks after I got my private.

Sorry about the thread high jack.

This is another one of those “good ones”. Sorry it is with your Subaru.

After reading about what has been done it sounds like just about everything related to the cooling system has been changed out, including the engine block. It would be incredible if this trouble was due to the radiator cap. In my opinion that should have been replaced way before replacing the water pump. I would also check the temperature with another test device like a infrared thermometer to verify the dash gauge. Something is gone awry here.

"Something is gone awry here. "

If the OP is paying for this service, I’m sure the dealer feels things are going just right…

The only one good thing about this is the service shop is eating the bill.

Hey guys just letting you know I’m still reading. Haven’t had a chance to get to the dealer in the last 2 days. Like you said Cougar, the only good thing here is the fact that I’m driving around in a free rental car. You’d think they’d care more about fixing it when they’re shelling out so much, but that’s neither here nor there.

Now on to my favorite subject: flying! Not to hate on the C-17 folks (good dudes, and a lot of my friends fly them), but you just never seem to hear about Herks landing gear up, or gear down at the wrong runway. The C-17 is a very capable aircraft but those guys are just way too overworked. I happen to love my Herk…not very glamorous, but it’s the old beat up pickup truck of the airlift world. Just keeps running and getting the job done no matter what you throw at it! The nice thing about flying a plane designed in the 50s is that everything that could possibly go wrong has, and now we know how to handle it.

MG: knock on wood, but this is the beautiful part of having a Navigator! 1500+ hours in, 200+ in combat, and every approach and landing at the right field…I’ve got a dude behind me that’s perfectly happy to start yelling if I do something that silly, and to remind me when my landings aren’t quite as smooth as they could be :slight_smile:

Seriously though, thanks guys for all your advice. I will keep posting as the situation develops and we eventually get it resolved one way or the other!

Thanks for keeping us up to speed on this and hopefully it will get resolved.

As to aircraft, the 117 is an impressive aircraft but I still like the 130 better. :slight_smile:
The 117s drop in here now and then for a touch and go or two but it’s not very common.
My mother in law lives under the pattern and at times in the past a C-5 has dropped in; a stunning sight looking straight up at one of those with gear down and at extremely low altitude.

And speaking of pilot error, 4 of them from the base here got in trouble for carrying the flyover at an Iowa college football game too far. Going over the stadium at 175 feet or so while moving at 400 knots dazzled the fans but not the Air Force brass. Three were reprimanded and one may have retired as his flying career was essentially over. An aircraft mechanical failure or clipping the scoreboard could have really made this performance go sour in a bad, bad way.
There’s even Youtube videos of this.

I wonder if a clogged converter would change the exhaust note enough to be useful as a diagnostic tool.

To the OP: at idle does the exhaust come out in distinct in distinct pulses (felt with the hand)
or is it a steady stream?

I’m reading this post for the first time and I noticed something in the description that makes me wonder if the thermostat wasn’t put in backwards. I don’t know if that is even possible, its not in most vehicles but it sounds like it is.

Off topic, the first combat delivery practice by a C130 that I saw was at Rota, Spain. I was sure the pilot was committing suicide, but he pulled it out about 30’ above the runway. I’ve never seen this demonstrated at an airshow, but it is impressive. BTW, did you ever see the black ops C130 that Lockheed built, only one of as far as I know but VERY impressive.