05 Forister with mystery overheating problem.

My brother has a 05 Forister and has a mysterious over heating problem. I asked him to write it up in detail so I can ask the Subru Gurus here. I am going to do a compression test (special high tech one that shows the whole cycle not just max compression) this week and see if it reveals anything.

Any and all sugestions are greatly apreciated.

I was thinking of doing another leakdown test with the motor hot. And of pressurizing the coolant system with the plugs out and leaving it for a while. This is sort of last resort testing at the moment.

What about a clogged cat?

Your thaughts insite is greatly apreciated!!!

My Brother said: Subaru Forester 2005, no-frills model... directly off the lot. Currently had 92K miles. Last year, around this time: Driving down interstate-93 on a fairly hot day (>90 degrees) with my wife in the car. We were going around... 70-75mph or so. I don't normally have AC on, but did for her. After about... 20 minutes of driving the temp started to go up. Not quickly, but consistently. Got to about 2/3 the way up. I pulled off, turned the engine off (left power on so the fans were going) and checked the fluids. They had reasonable amounts and colors (I didn't check the radiator, only the overflow, for obvious reasons.) A nice worker for the highway department let me out an emergency ramp and directed me to a much smaller and slower road. I drove all the way home never breaking... 40mph. Watched the temp like a hawk and it was fine. Took it to my independent mechanic and he couldn't reproduce the problem and didn't find anything wrong. Took it to the dealer I purchased it from and they couldn't reproduce it or find anything wrong. One of them might have flushed the radiator, I don't recall. No "serious work" done. Car worked fine for almost a year, including a 6+ hour interstate-highway drive on vacation across 4 states a few months later. Fast forward about a month ago.... the story starts the same: Driving down interstate-93 on a fairly hot day (~90 degrees) with my wife in the car. We were going around... 70-75mph or so. I don't normally have AC on, but did for her. After about... 20 minutes of driving the temp started to go up. Not quickly, but consistently. Got to about 2/3 the way up. This time I experimented more. I turned off the AC, slowed the car down to around ~55mph and the temp went down a bit but didn't go all the way down. I sped up a bit and it went back up and didn't go down very well. I turned on the heat full blast, opened the window and slowed down as much as I dared on that highway (50?). The temp did go down. Got off at the next exit and went home on a smaller "Route" at 40-50mph, watching the temp gauge. Heat not always on. It was fine. When I got to I-95, I got on that and kept the speed at 55 and was fine. I then experimented again and sped up (without AC) to... maybe 60-65 and the problem came back (definitely lower than my speeds when the problem started.) It didn't go down the way I liked when I slowed down so I turned the heat back on and rolled down the windows. Got home fine. No surprise, I couldn't reproduce the problem leaving it running in the driveway with the AC on full blast. Took it to my mechanic again. He couldn't find the problem but his research showed it as similar to: - Water pump starting to fail, so either doesn't work as well as it could or doesn't always work. - Head Gasket. But this has other signs that weren't there, like anti-freeze in oil and oil in anti-freeze. They both looked fine. So he offered to replace the water pump (something you'd probably just do within the next 10K anyways.) While there he did the belts and the thermostat. I also had him do a leak-down test which showed no problems. I had heard a noise when turning left and he found the front ball joins (?) were going, so I had him do those at the same time. I wanted to keep the car, after all. The car had worked fine since then... until today. But today the story is different. I was going down I-95 (no wife in the car - she isn't bad luck) at around 70mph, NO AC going. It was on defrost/vents (not full-defrost) for what it's worth (does that use the compressor?) Temp set to fairly low, fan on. The temp started to rise. I didn't wait until it got to 2/3 from the top. I changed directions and just went home. At one point it did start going up again, so I got off the phone (calling the people I was visiting to say I wouldn't make it) and turned on the heat full blast. Had I sped up too much? I don't think so, but I was slightly distracted by the phone. Either way, that helped and the temp went back down. The car made it back just fine. At this point I don't think I can take it back to my mechanic, so I'm going to call the dealer and see what they can figure out. Any ideas? I would like to get the car fixed... I had hoped for another 100K at least on this car. But at this point, I don't trust it... and I can't keep a car that I don't trust to drive around. Oh, another point that might matter. When I purchased the car the temp normally ran at a little bit over 1/3 on the temp gauge. About 40-50K of having the car it started to run higher... a bit under 1/2 way. My mechanic said the temp looked fine (within operating spec of the car) when he read it via codes so said I shouldn't worry. It's been that way for awhile and seems fine. --------------------- Eric

Clogged cat? Sure there wouldn't be more problems caused by that? I'm sure its a welded system so you can't just pop it of and test run it.

If put my money on something simple being overlooked.

Good luck.

Radiator is clogged internally, IMO. Although I would also suspect a bad rad cap too. If it is losing pressure, you are lower the boiling point of the coolant, which will cause an overheat.

either radiator is restricted or..... headgasket allowing air to pump into cooling system and cause a false overhead. personally i would flush the radiator with a good flusshing chemical. then replace the radiator and thermostat. and retest. if still does it then your left with headgasket. im guessing you have the 2.5? which it is common on those. also add some water wetter when you replace the rad.

I realize that this is 2 months old, but I'm dean1484's brother and I have some more info.

The car had worked ok, but I hadn't gone on long trips. I went on vacation and on the way back, it happened again. No AC, highway driving. The usual.

I took it to the dealer I purchased it from after my mechanic basically told me to not bring it to him. He just isn't sure. They found a collapsing hose coming out of the bottom of the radiator. Said it only happened at high RPMs. Replaced it, new fluid, new temp sensor (even though the old one was only a month old) for a little over $300. This sounded great, fits the symptoms fairly well.

Even did a test drive for about an hour. Down to interstates, good highway speeds. No problem.

Foolish me. I started on my annual 6-7 hour drive to see the inlaws (maybe that was my problem!) About 2 hours into it, it overheated the same way. I limped to a Subaru dealer up there (Maine), got a rental car and forgot about it for several days.

They called and named all the things they saw that were done (nice to see they used new parts) and basically said what others have said. No exhaust gases or oil in the anti-freeze, but its probably a head gasket. They gave a good price... I probably should have had them do it. But I was so frustrated with the car I had decided at that point I was just going to sell it and get a new car (what? I don't know... a CRV? I do like the Subaru, but I feel odd getting another one after all this.)

After the vacation, I came back down, picked up the car (no work done) and limped home on back roads for nearly 4 hours. Never going above 55mph and it worked like a charm. No issues.

Now I'm at home, going the 20 minutes to work (just fine) and thinking about it.

With all this info, is the ~$1,600(?) for a head gasket worth the risk? Part of me doesn't want to risk overheating again after another failed fix, but another part of me says "do you really want to spend $15K on a CRV after trade-in? When a lot less could fix it?"

Oh, a point to the people about the radiator. On another trip to the inlaws I overheaded quickly - no coolant. To make a very long story short, a warranty repair replaced the radiator, flushed the system, and more. That was around.... 50-60K ago.

Other than the collapsing hose, no one has been able to reproduce any problem (but me :) .)

I guess I just don't have a good understanding of the gamble I'm taking with the cost of the head gasket. I'm better with informed decisions.

And to throw this into the mix, Dean sent me this link: http://allwheeldriveauto.com/subaru-head-gasket-problems-explained/ which does sound kinda like my problem (pointing to head gasket) but I though that design issue was generally fixed in the '05 and newer models.

Any ideas are greatly appreciated...

Forester.org overheating threads

If you're happy with the car other than the current HG issue, I'd say fix it and be done with it.

Not sure what area you're in, but check around on HG pricing. There's a guy in east/central Pennsylvania that does them for $1,000. He buy's up Soob 2.5's with bad HG's and flips them, so he has done a bunch.

May be someone similar near you?

I just did HG's in my mom's 05 but it wasn't overheating - just leaking oil.

I replaced all the pistions while I had it apart that far and the entire thing was about $1k in parts. The pistons were about $250 of it. We also replaced the oil pump. Make sure you pack the oil pump with vasoline if you replace it like I did.

I do Subie HG's on the side and I've seen them with collapsing hoses as well. Not sure why they do that. I even had one with a pulled head stud. That was a pain to figure out.

erics wrote: Oh, a point to the people about the radiator. On another trip to the inlaws I overheaded quickly - no coolant. To make a very long story short, a warranty repair replaced the radiator, flushed the system, and more. That was around.... 50-60K ago.

Wait, you had a no-coolant overheating incident and they did not replace the headgaskets?

This should be a red flag.

peter wrote:

erics wrote: Oh, a point to the people about the radiator. On another trip to the inlaws I overheaded quickly - no coolant. To make a very long story short, a warranty repair replaced the radiator, flushed the system, and more. That was around.... 50-60K ago.

Wait, you had a no-coolant overheating incident and they did not replace the headgaskets? This should be a red flag.

WOW I missed this as well. This makes me even more convined that it is the headgasket. Just for S&G's what does a reman motor go for? Even if it was say 4K and you get 100K miles out of it you are still way ahead of the cost of a new car.

BTW Eric are you comming up here tomorow? The fishing has been very good!!!!! I would almost call it "catching" not "fishing" LOL

How is the air flow to the radiator ? Clogged cat would show reduced power and is easily checked with a vacuum gauge.

I'd verify that the second fan comes on when the A/C is on, and make sure there isn't lots of debris between the radiator and the condensor restricting air flow. A/C does come on when the defroster is selected by the way. I'd also check the radiator with a pyrometer just so you know the temp sensor is OK. Wouldn't be the first time a gauge displayed less than accurate info.

From my distant memory... the original excuse on the radiator replacement (maybe to avoid a warrenty-covered HG replacement?) was that the wrong antifreeze was used, which clogged up the radiator and it went downhill from there. I literally had no other issues... it went from behaving fine to having no coolant. Dean suggested I drive it until it explodes and get the engine replaced under warranty... If I hadn't been 6 hours away from home with a full load of vacation stuff in the car, that would have been tempting.

I will call around on the HG work. It would be nice to not pay the "dealer markup" for this one. I know a few places to check, and I'm sure Dean can suggest some as well. I'm up in MA outside Boston.

I don't know if any tests were done on the Cat. I will investigate that as well. I don't have the equipment to do it myself.

I do know the fans on the inside of the Radiator turn on (I've checked), if that is what you mean by "second fan". On one trip I had gotten up very early, so I did have the defroster on... but I do know it uses the A/C, so I generally only do that for as little as I can.

Sounds like the popular votes are: - get the HG done, its generally a good car that will last you. - Check the Cat - Check the Temp sensor is really reading right

Get the head gasket done and while the heads are off get them pressure-tested or at least have someone look for cracks. I cracked my WRX heads during a coolant-loss event, my machinist told me that once the coolant goes, you're pretty likely to crack a head. YMMV.

I have more news, and a quick thanks to everyone here.

I went to the dealer before going on vacation (literally, with a car full of stuff. I didn't want to put off talking to them any more.) I went to the showroom floor and said I wanted to talk to someone in management. The guy next to me turned and said he's the general manager.

I told him my tail of woe (including the earlier loss of coolant and how I was very unhappy with how they treated me) and all the failures to fix it and my costs on the rental and all. I don't normally get mad about stuff, but I did my best to express my displeasure.

I now have a free courtesy car which I took to NH for the weekend vacation - nice to not have to worry about that. And I keep until they fix the car. I got a call today saying low and behold it was the head gasket. I won't ask how they missed that before. They tried to claim it would be $2,600 normally, but they're talking with Subaru America to get them to cover all but "a $500 deductible." If that comes through, you bet I'm taking it Better deal than I expected. Since they messed up before figuring it out before, they're looking more to see if anything else might be wrong. I should hear tomorrow at some point.

I'll report back when I know more.

Excellent! Sounds like you are working with a decent dealer. Some can be real a**holes about stuff like this.

n/a 2.5 Subie engine? Needs headgaskets. In fact, out local guys just do them when they do the timing belt as PM. No lie.