More Overheating Problems with the Subaru

Well, I’m back…my sons Subaru Outback came back from the mechanic and was running without overheating for about a day before it started in again. They claimed it was the radiator cap. Then the next day it overheated again - they claimed it was a defective cap…now it’s back in there again, with the same overheating problem. The mechanic says that it is not the head gasket, and when they pressurized it there were no leaks…HELP! What the heck is the problem?

What’s the problem? After two trips to the same dealer I’d be tempted to say their mechanic is what’s the problem.

No mention of a changed thermostat.

No mention of plugged coolant hoses or rad.

Is there any loss of coolant when the overheating occurs?

The coolant temp gauge shows in the red and a warning light is on on the dash when it overheats?

Was the blower fan pushing hot air OR cold air out from the heater vents before the engine overheated?

What year and how many miles on the vehicle?

I think it’s the mechanic…I have not been driving it so I do not know if there is any loss of coolant when the overheating occurs, but I will find out. They changed the thermostat when we first brought it in for service. It’s a 1998 Outback Legacy with 100,000K miles. I should mention it is not the dealer we’ve been taking it to…it’s a mechanic we’ve used for a few years for other issues. I’d also like to know what is the difference between a pressure test and a compression test? I’m still the same “car idiot” that I was last time.

What are the signs of “overheating”? How much? Car moving? Stationary? Pulling a hill, or a load?

A cooling system PRESSURE TEST is performed by pressurizing the radiator by using a pump inserted in the top opening. It will detect even small cooling system leaks since the pressure will slowly go down. These leaks are often invisible with the engine off.

A compression test is used to determine how healthy the actual engine is. Ususally the pressure gauge is put into each spark plug hole with all spark plug wires disconnected, and the engine cranked over a few times. The gauge will read what the actual pressure was in Lbs/square inch, and this is compared with the factory figure for a new car.

As cars age they gradually lose compression; this is not a problem as long as all cylinders lose equally. A 15% difference between the best and worst reading is borderline; anything more requires an engine overhaul. If all cylinders are down 15% from new you need an overhaul as well. The readings are often given as a % of new; one old car I had at 220,000 miles the readings were 6 cylinders at 100% and the remaining ones 96% and 94%. This engine was considered sound.

Hope this answers your question.

That was very helpful…thanks.

I had a problem with a 1998 Subaru Legacy a few years ago. The symptom was that I could let the car sit all day long, and it wouldn’t overheat. I’d start driving and ten minutes later it started overheating.

I changed the thermostat and nothing changed. The next time it happened I was away from home, and the mechanic there changed the water pump. He had the car idle for a few hours, and it was fine. I drove it home and didn’t get 20 minutes away and it started overheating again.

Brought it back, and they looked at it. Told me that the radiator was clogged, and clogged so bad they needed to replace it. That actually seemed to work for almost a year, and then all of a sudden the exact same symptoms. I could let it idle forever and nothing, but ten minutes onto the road and it would overheat.

Finally my regular mechanic tested it for a head gasket leak. I think he said he tested by hooking something up to the radiator, where the cap would normally go, that was like a funnel that was then filled with coolant. Started running the car and the coolant started shooting out. He found out that the exhaust was leaking into the coolant. He tested the heads, replaced the gasket, and it’s been a few years now and everything is okay.

I know you said he tested for a head gasket leak, and I don’t know if you have the exact same symptoms, but it’s a thought.

The air starts blasting cold if the heat is running. The temperature gauge goes up, but we stop driving it before it gets in the red. It all happens while driving, not when stationary. It happens on typical in-town roads, not hills. There seems to be fluid coming out near the radiator cap, but it’s been replaced twice. Does this help? I was also corrected - the car has 96k miles. I do appreciate all the replies!

When a cooling system pressure check is done, it’s without the radiator cap. There may be a problem (warp, a crack which opens in the neck) where the radiator cap seal sits against the opening of the radiator.
Also, when a radiator is pressure tested, it’s usually only luke warm, by then. IF there is any crack which opens, it could be opening only when the parts are hot. The crack, and thus the leak, wouldn’t show up when they’re cooler.

Sure seems like a blown head gasket to me. The cooling system is pressurized to check for a coolant leak. The compression test is done with a gauge in the spark plug hole and the engine is cranked to get the reading. Here goes a “likely scenario”: The previous owner had a head gasket leak and poured stop leak into the radiator and the stuff clogged the radiator. That would explain the overheating. I think there is a blown head gasket. If the radiator cap is on the end of the radiator, you can drain the coolant and see if there are deposits clogging the radiator tubes. If you don’t see that; you can bet on the blown head gasket. Hellokit is also right on the money.

This sounds almost exactly like what is happening, but within days, not years. The mechanic will drive it around and whatnot and nothing - then we get it back and it ramps up again.

I asked my husband if it might be the radiator, but he blew me off…probably because I know next to nothing - but it seemed like a logical conclusion. *Just so everyone knows, I’m not bad-mouthing my husband - he’s the best, he’s just not a full-time mechanic (more of an arm-chair mechanic).

I keep telling my husband this, too! I think I need to have him read these posts!!! Again, thanks! Anyone want to move to Alaska to become my mechanic??? :0)

The problem does sound to be with the gaskets to me also. You have the classic symtoms for it. If you live in Anchorage check out Specialized Import. They are Subaru specialists and will know what to do for this.

Well, everyone told me and told me it was the head gasket…the mechanic called this morning and said it was the head gasket. He said that needs to be replaced, along with the water pump and various other items. I am not at all happy (mostly with my husband for rushing into a purchase - and at the “nice” person who sold it to us and probably knew about the problem), but buyer beware, right? ***Update - the mechanic wants to replace the head gasket, the water pump, the clutch assembly (while they are in there), timing belt (preventive), and reseal the oil pump. Estimates are ranging from $1800-$3000 depending on where we have called for estimates. I just really think we (not me, I wasn’t involved with this whole purchase) got suckered. My question now: IS IT WORTH FIXING, OR SHOULD WE SELL IT?

Well, I guess that you have learned the hard way that it is important to do some research on cars before buying a used car (or at least your hubby should have done some research that would have revealed the known problem with head gaskets on Outbacks of that era). And, of course, this does not say very much in a positive sense for your mechanic.

That being said, the car itself undoubtedly has at least 50k of good service left in it if the head gasket, the timing belt, and the water pump are replaced. So, unless you can buy another car for the price of the repairs, I would suggest having it repaired.

As to selling it, unless you reveal the bad head gasket and the likely overdue timing belt replacement to potential buyers, you are no better than the “nice person” (your words) who sold it to you. Unless you are willing to do full disclosure, and willing to take the financial hit for the greatly decreased resale value of that disclosure, you will be no better than the person who sold the car to you.

Avoid bad karma, which inevitably comes back to bite you in the behind. If you sell it, reveal everything that you know about the car.

I agree with VDCdriver and suggest you keep it if the body and rest of the car is in good shape. You should be able to get a lot of service out of the car after the repairs are done correctly. If you are near Anchorage, I recommend you have Specialized Import do the job unless you know the repair shop folks you are dealing with.

The other things that were on the list to replace are all the normal things that should be done when doing this job so I would say they are on the ball and you should have them replaced also.

Hopefully you got a pretty good deal on the car when you purchased it so the repair costs are a little easier to take. These are good cars except for this particular problem. Be sure you get the lastest version of Subaru head- gaskets and I would insist they only use genuine Subaru gaskets. The newer head gaskets eliminate the problem.

One other thing you should look into. Subaru extended the warranty for the headgaskets since so many engines had this problem. I would check with the Subaru dealer and ask them about it. I think the warranty was good for 100,000 miles.

My 2003 Subaru 3.0 6cyl I thought was over heating because the gauge would move into the red heat range when driving on hills/climbing. The dealer replaced the radiator and that didn’t solve the problem. Then the Thermostat was changed, still had the same problem, then replaced the thermostat again, same problem. Finally " I " changed the temperature sending unit and the problem was solved even though the fan always worked the sending unit was sending a false signal.