I have been resisting starting this thread but I figure I may as well bite the bullet...

 

Car is my wife's 1997 Legacy.  Non turbo EJ22.  285,000 miles on the clock.

 

Never had any overheating issues in the 200,000 miles that we have owned it.  Then, out of nowhere, the temp gauge spiked on a short drive about a week ago.  My son was driving at the time and it was late at night. So the next day I popped the bonnet, removed the radiator pressure cap and checked for coolant.  Unfortunately I did not measure exactly how much, but I was able to add somewhere between a pint and a quart of coolant.  I then ran the car it did not overheat.  I removed the electric fans so that I could get a better look at the radiator and ran it some more.  No overheating and no visible leaks.  With the fans removed, the temperature gauge does eventually creep up beyond the normal 1/2 way point but if you then drive the car it quickly comes back down to where it always has run and stays there.

 

A couple of days and a few miles later I again opened the radiator cap and was able to add 4 or 5 ounces of coolant.

 

Drove it to work this morning without issue.

 

I will leave the description there and hope the collective will pose some questions and/or make some suggestions.

 

Thank you!

 

Mike V.

I hope that you know that your symptoms are the classic description of a internally leaking Hg.  Of course there are other possibilities.  But old 2.2 engines can leak internally.   I had a 1995 at 217K that ran just fine, but if you looked close, there were continuous, little bubbles in the the overflow reservoir.  I had to junk it because of rust on the rear frame but it would have overheated pretty soon.  So check your reservoir.

 

ps.  congratulations to getting to 285K miles.

 

pss  they are called hoods, not bonnets, in US.  Bonnets are what women wear on Easter.

gotta find the leak - it's either a small/slow external leak you're missing during driving. 

 

or it's loosing it internally which is usually an internal headgasket breach.   some idle controllers have intake/coolant passages separated by a gasket - conceivably they could leak internaly tha way - but it's not common, i've never seen or even heard of it happening, but at 20 years old and 285,000 a lot of things are more probably than they used to be. 

 

those EJ22's headgaskets aren't too bad -  remove timing belt, intake, exhaust then unbolt, resurface, and reinstall heads.  

Pull the spark plugs, if some of them are way cleaner than others, you probably have an internal headgasket leak. If all the spark plug look the same I wouldn't assume internal leak right off the bat. Other common symptom of a headgasket issue is the radiator overflow tank fills all the way up and eventually overflows.

 

Same thing I tell anyone who has a leak they can't find. Clean the entire engine really well, get all the grime off the bottom, etc. Then you'll have a flying chance at finding the leak. You can even add UV dye to the coolant if you wish. 

While trying to find the cause, check that coolant level and fill before each drive. Level in overflow, and check the radiator by sharply squeezing the upper hose. Listen for the giggle pin and gurgles. More air each time, bad, find the leak. Less air, ok, good. Run over normal temperature while low on coolant has always lead to needing headgaskets in my experience.

While trying to find the cause, check that coolant level and fill before each drive. Level in overflow, and check the radiator by sharply squeezing the upper hose. Listen for the giggle pin and gurgles. More air each time, bad, find the leak. Less air, ok, good. Run over normal temperature while low on coolant has always lead to needing headgaskets in my experience.

Agree with others that it is likely bad head gaskets. My own personal experience with 3 Subarus, they eventually all blew their head gaskets. Typically, the problem starts with just occasional over heating, which leads to worse and worse. What ever you do, don't drive the car when it starts to over heat. Turn off the engine, and let the motor cool off. Continue driving while over heating will warp every piece of aluminum in the motor, plus ruin the main bearings.

 

If and when it starts to over heat, immediately check to see if there are bubbles in the radiator over flow tank. The bubbles will look like bubbles produced from a fish aquarium  aerator bubble system. If you see that, then it is a lead pipe cinch guarantee that you have bad head gaskets. Game over, replace the head gaskets. The bubbles are caused by exhaust gas being forced into the cooling system through the bad head gasket. Bad head gaskets on Subarus never show oil in the coolant, or coolant in the oil.

 

If bad head gasket is determined, you can still drive a bit longer before repairing by loosening the radiator car to relieve the air (exhaust gas) pressure. This means constantly replacing coolant, but it lets you drive the car for a while. Just don't run low on coolant.

Thanks for the suggestions so far!  Before I go any farther I need to know , What is a "Giggle pin"?

The giggle pin is what goes off when you tickle your subaru just right.

The jiggle pin is the little rattly pin thingy in the thermostat that helps bleed air out of the system.

Oem and higher quality aftermarket thermostats have the jiggle pin. It makes a faint sound when you sharply squeeze the upper radiator hose when the system is full of coolant.

Wow, jiggle pin, huh?!?  Never heard of that one before.  I will have to squeeze and listen (you guys wouldn't be putting me on now would you?).

 

Just to keep everyone up to date.... Upon arrival home from work last evening (temperature normal) I popped the bonnet (er, opened the hood) and did see a drop or two of coolant on the frame section that runs just beneath the radiator (remember, I have the electric fans removed so I have good visibility to check for any leaks).  Was only a drop or two but it was dry the day before and it had to come from somewhere.  So at this point I am not ruling out that the whole problem is a small/slow leak out of the radiator somewhere. 

 

If the problem is a leaky/failing head gasket, is it possible that the engine would only overheat sometimes?

If the problem is a leaky/failing head gasket, is it possible that the engine would only overheat sometimes?

 

 

Yes, with my 3 Subies, "sometimes over heating" became the start, that became worse and worse over heating over time. Seemed like adding stress to the cooling system as in freeway driving, or climbing hills would cause over heating. Little stress like idling would not cause over heating. All 3 of my cars would idle forever, and not over heat, but bring on the stress, and the temp gauge needle would climb in a hurry.

The overheat happens due to enough air building up to impede the cooling system from doing its job. Yes, heavier loading will cause it to show up quicker. In mild cases, I suppose it could be air pockets cause hot spots, damaging the headgaskets. Get enough air in there, and it can interfere with the waterpump's ability to move water, as in, waterpump are really bad at pumping air, and can't suck a big pocket through.

Thanks for the comments fellows.

 

It does make sense that if there is a weak, but not totally shot, area in one of the head gaskets  that it may be able to seal under light engine loads but at higher loads the combustion pressure is greater and the weak point may not seal under those conditions.

 

When you say "air" I assume you mean combustion gasses.

Yes, it's not really air, once you stop opening the cap, assuming there are no other external leaks.

 

Seeing those drops of coolant on the frame is something to go looking for the source of.

Sense it appears to be early - if it's the hg as seems likely - would now be a good time to add some Bar's or equivelant? I ran my 2.5 for another year after adding some. Note I caught it early.

Find your leak at the radiator. Either a hose leaking at the clamp or one of the end tanks has split. Low coolant level will quickly lead to overheating on these. 

Upon arrival home from work last night I looked but was not able to see any external leakage. This was disappointing as I was hoping to see more coolant sitting on the frame member (I guess it actually would be termed the radiator support) that runs beneath the radiator. But it was bone dry. So I removed the radiator cap and was able to add 22 ounces of coolant. And I last topped it off about 60 miles ago. So there definitely is an issue and I would think that I would see coolant dripping onto the ground or pooling up somewhere on the engine (even though it is filthy) if the leak is external. Next I removed the spark plugs. While all four do not have identical appearance, none of them jumps out as looking different (i.e. cleaner) than the other three.

So I am pretty much in a state of indecision at this point. I am not 100% sure it is a head gasket issue and I would hate to do anything rash without knowing that was the case. On the other hand, the body rust is getting advanced, it is beat up and, as I said, the car does have 285,000 miles on it. So if I weren't poor it would be an obvious time to replace the vehicle

22oz? That is a lot.

To determine if it's a leak or headgaskets, the checking I described above must be before every cold engine atart, and the air and coolant levels noted, to see a trend. Only then do I determine its the headgaskets, after searching for other sneaky leaks.

 

Typically, the headgasket pinhole leak doesn't consume coolant, it adds air. Eventually pushing coolant out the overflow of the recovery tank.

yes they can be random and variable, very common.  

 

one would think a breach should immediately get worse with combustion temps/pressures, but somehow they don't always.

 

the EZ30D is even crazier - it can overheat once or a few times and then not exhibit issues again for a year, or even only hvae issues above a certain ambient temperature and A/C on - i've seen it multiple times. granted they eventually get worse and are easily discenerable.  i get it, but at the same time i'm surprised that it can vary based on ambient temps considering how much smaller they are from combustion temps and how the engine is presumably well regulated in temperature by the cooling system.  there's very few people i would have even believed if they had told me that before i'd seen it multiple times. 

Thanks guys for chiming in.

 

OK.  I have been running around without the electric fans installed which means that I am also running around without the expansion/overflow tank installed so I do not know for sure if the coolant has been exiting via the radiator cap and out the hose onto the ground.  If so, I would have expected to see coolant sprayed around, but who knows?  So I will reinstall the fans and the tank and then start monitoring the level in the expansion tank as well as in the radiator itself.  I still do not know how I would check the "air" level. Sorry if I am dense. 

 

You guys are advising me that head gasket issues and the associated temperature issues can be random and inconsistent so that means I cannot trust this car which means I can't rely on it for my wife.  I might see if she'll swap cars with me for a while which she will not be real happy about....

 

Mike V.

1992 Legacy sedan(mine)

1997 Legacy Brighton Wagon (wife's)

2008 Legacy GT (kid's)

Running without the overflow tank is bad.

 

That would end up requiring air in the system, and cause overtemps.

 

The air level is checked by sharply squeezing the upper hose. Never open the radiator cap, unless that test shows signs of all air, and that you could add coolant directly to the radiator.

Better unhappy than stranded! Unless it's my wife. If she's unhappy I want her stranded

Better unhappy than stranded! Unless it's my wife. If she's unhappy I want her stranded

ahahahahaha

Get a radiator pressure device and pressurize the system. If the leak is external you will likely hear a hissing sound or be able to see the coolant leaking out. Giggle the hoses and poke around. You can also try a dye that you add to the coolant then use UV glasses to locate the source of the leak if it's external.