My new station wagon - I bought it with knowing the problem - has an overheating problem, a mysterious one somehow. It's a 1994 1st gen Legacy 2.2 without a/c and automatic transmission.

 

I registered the car on Friday and drove about 80 km (50 miles) without problem (even idling for about 20 minutes) while it was quite hot. On Saturday it was much cooler and I drove for about 20 km (12 miles) and suddenly the temperature was quickly rising from normal to hot. I immediately pulled over and checked. There was much water coming out of the overflow of the coolant expansion reservoir.

 

And now something mysterious happened: I picked up some coolant fluid to refill and opened the cap of the coolant expansion reservoir. It was full to the top. And suddenly the coolant was sucked back in the cooler really fast. It was like if you have a glas of Coke and trink it with a straw. This was so quick... I put in about 1.5 liter of coolant before it stops. I was then opening the cap of the cooler and there was no pressure or vacuum on it. No visible leak, nothing odd.

 

I then start the engine again, temperature was back to normal, I switched on the heating for checking and drove home. When I nearly got home, the same happened again, the temperature of the heating dropped so there was too few fluid in it. I hadn't time for more checking since I need to get somewhere and just picked my other car.

 

So, has anyone any idea about that? I have never seen something like that sucking back ever again nor heard about something like that. Anything is appreciated!

 

Thanks!

Edited June 12, 20169 yr by stickedy

you may have witnessed 2 problems, not just one - but, the overheating needs to addressed - quite likely a head gasket is leaking combustion chamber pressure into the coolant passages.

 

It's normal for the radiator cap to allow atmospheric pressure to push coolant back into the radiator as the car cools - but , your radiator cap 'could' have a problem, related to it's age if original, or - perhaps it's a poorly selected aftermarket unit. I wouldn't discount the possibility of some type of 'stop leak' or similar additive having been added to the cooling system  as an attempt by a previous owner to deal with the overheating. It should be mentioned also, that OEM Subaru thermostats have a larger wax capsule than many aftermarket thermostats - that 'could' also be a problem.

 

Should it happen again, check the radiator over flow container. If there are bubbles in the tank, then it is a sure sign of a bad head gasket. What ever you do, don't drive it when the engine is over heating. It will destroy the motor.

 

Suspect previous owner knew of this problem prior to selling the car to you. Ask the previous owner, maybe you can get some restitution.

Should it happen again, check the radiator over flow container. If there are bubbles in the tank, then it is a sure sign of a bad head gasket. What ever you do, don't drive it when the engine is over heating. It will destroy the motor.

 

Suspect previous owner knew of this problem prior to selling the car to you. Ask the previous owner, maybe you can get some restitution.

 

Yeah, he knows about it. And I also before buying it. And therefore the car was cheap, I buy it with the idea of either fixing or exchanging the engine. The rest of the car is in really good condition, so it was a good deal. But if it's an easy fix, I want to avoid exchanging the engine, since there funnier things to do during a day

 

On Tuesday we will check compression on all cylinders and tomorrow I try testing again while idling and looking for bubbles.

you may have witnessed 2 problems, not just one - but, the overheating needs to addressed - quite likely a head gasket is leaking combustion chamber pressure into the coolant passages.

 

It's normal for the radiator cap to allow atmospheric pressure to push coolant back into the radiator as the car cools - but , your radiator cap 'could' have a problem, related to it's age if original, or - perhaps it's a poorly selected aftermarket unit. I wouldn't discount the possibility of some type of 'stop leak' or similar additive having been added to the cooling system  as an attempt by a previous owner to deal with the overheating. It should be mentioned also, that OEM Subaru thermostats have a larger wax capsule than many aftermarket thermostats - that 'could' also be a problem.

 

I know the coolant should be sucked back when cooling down, but I'm irritated by the speed. The whole action from stopping the car to a fully refilled cooler didn't last more than 5 or 6 minutes. In this time, there can't hardly be any significant cooling down in my opinion. Or am I wrong on that point?

 

I tested the cooler cap in my other car - the soon to be replaced one - it's working fine. That was my first idea after buying the car. Hmm... However, could it be that the cap can't hold the pressure sometimes and sometimes can? I'm not used to problems with the caps, since I didn't face any yet.

 

Thanks for your ideas. I will test the head gaskets (compression) for sure.

this recent thread may be helpful - and you might try searching for others; http://www.ultimatesubaru.org/forum/topic/159313-pulled-the-heads-advise-on-how-they-look-please/

"Thanks for your ideas. I will test the head gaskets (compression) for sure."

 

Unlike other cars, Subarus with a bad head gasket will not have any compression issue, or mixture of oil in the coolant, or coolant in the oil. The head gasket breaches between the exhaust, and the coolant. Result is hot exhaust gas enters the cooling system to cause engine over heating. It is not a constant problem at first. Car engine can idle all day, and not over heat, but stress the head gasket with a run on a highway, or climb steep hills, and the breach will open to cause rapid over heating. I have had this happen on all three Subarus that I have owned. Your 2.2 motor is not prone to blowing a head gasket, but it can happen. The 2.2 motor in my 91 Legacy did just that. I hope the motor in your car has not been seriously over heated a number of times. If so, the over heating limits the life of the motor.

 

As mentioned earlier seeing bubbles in the rad over flow tank when over heating is a sure fire way to confirm bad head gaskets. The bubbles is/are the exhaust gas that has gotten into the cooling system.

 

If head gasket breach confirmed, I have read where guys have removed the thermostat, and open the bleeder screw on top of the radiator to bleed off the exhaust gas. Doing this will reduce over heating, and let you drive the car some, until you either repair the head gaskets, or swap in a replacement motor. Just be sure to top off the radiator coolant to keep the system full, when the system gets low from trickling out.

Sounds like classic head gaskets on the ej2.2.  that i have learned.   they are easy to change also.

"Thanks for your ideas. I will test the head gaskets (compression) for sure."

 

Unlike other cars, Subarus with a bad head gasket will not have any compression issue, or mixture of oil in the coolant, or coolant in the oil. The head gasket breaches between the exhaust, and the coolant. Result is hot exhaust gas enters the cooling system to cause engine over heating. It is not a constant problem at first. Car engine can idle all day, and not over heat, but stress the head gasket with a run on a highway, or climb steep hills, and the breach will open to cause rapid over heating. I have had this happen on all three Subarus that I have owned. Your 2.2 motor is not prone to blowing a head gasket, but it can happen. The 2.2 motor in my 91 Legacy did just that. I hope the motor in your car has not been seriously over heated a number of times. If so, the over heating limits the life of the motor.

 

As mentioned earlier seeing bubbles in the rad over flow tank when over heating is a sure fire way to confirm bad head gaskets. The bubbles is/are the exhaust gas that has gotten into the cooling system.

 

If head gasket breach confirmed, I have read where guys have removed the thermostat, and open the bleeder screw on top of the radiator to bleed off the exhaust gas. Doing this will reduce over heating, and let you drive the car some, until you either repair the head gaskets, or swap in a replacement motor. Just be sure to top off the radiator coolant to keep the system full, when the system gets low from trickling out.

 

Ah, I see! That explains everything. I didn't have the information about breaching the head gasket between exhaust and coolant. So I will try to confirm the damage today (bubbles).

 

And if so, I will exchange the whole engine. Since I have a LPG modification in my other car and I also have to swap that over (for money matters) - and the a/c - , I don't want to fool around with changing head gaskets then. I will do that with my brother, both cars besides each other, should be a quick thing It's not the first engine, I exchanged several EA82 in the past, so no problem in doing that at all. Bu you know, avoiding work is always the target

So, I verified it: Bubbles in the coolant expansion reservoir when overheating.

 

Tomorrow I'll swap the engines.

So, I verified it: Bubbles in the coolant expansion reservoir when overheating.

 

Tomorrow I'll swap the engines.

Well at least you found the answer to why the motor over heats. 

 

For what it is worth, when swapping in a Subie motor, you don't need to open the AC system. The compressor can be moved out of the way, when pulling the engine.

Yeah, that's for sure. And learning something new

 

The overheating car has no a/c so I have to swap that over also.

Edited June 14, 20169 yr by stickedy