Just what can cause overheating? I have a 91 legacy Ls.. and it runs great, but it keeps overheating.. the local dealership changed the thermostat and put in new coolant.. but the same thing happens.. is there a thermal sensor that could cause this to happen?? the 2.2 is the "best engine" subaru has made according to many.. what about the head gasket? are these engines prone to the problem? I don't want to sell this for nothing if it is worth keeping. it only has 150 K and was NOT beaten at all by previous nuclear family.. any help is appreciated.. I am getting desperate! thanks

Could be many things, yes the 2.2 seems to be a pretty bulletproof engine(my 91 Legacy L has about 243K miles on it and still running strong). I would approach it not as a Subaru but as a car-it is overheating, check each component and see if it is consistent with the symptoms. If the thermostat has been changed, can prolly rule it out but can always get a bad one off the shelf-or it was installed improperly.

 

To help us diagnose, does it overheat idling? Driving around town? Or only when you get it on the highway? Depending on your mechanical ability/experience, I would check for a clogged radiator, functioning water pump, etc. Or have a trusted mechanic do it for you. If all checks out then yes, a head gasket could be the problem, if you see bubbles in the radiator or a "sniffer"test confirms it then that would be an issue but the 2.2's do not seem to have the HG problemsthe 2.5's have had.

My EJ22 needed new head gaskets at 125k miles and 10 years of age.

 

It is NOT a weakness of the EJ22. I suspect that the previous owner of mine had overheated once or twice due to a more normal failure, like a leaking radiator hose. They probably drove it while it was too hot and that warped the heads slightly and caused the HG leak.

 

If your car is overheating under mysterious circumstances, and never seems consistent in it's behaviour, then I would suggest a bad HG. Have the coolant checked for hydrocarbons and carbon dioxide.

Oh, and it's well worth paying for a good mech to do the HG work. I sold my EJ22 Legacy to a friend and he's just passed 200k miles!

Make sure the outside of the radiator isn't blocked along with the A/C evaportator. Does the car overheat when you're stopped at idle? Does it run hotter when cruising and get hotter the faster you drive? If stopped and it overheats, check the fan and temp switch on the radiator. If it runs hotter the faster you go, it's likely time to change the radiator.

One thing not mentioned is how old is the water pump. I lost my 2.2 years ago because I had a catastrophic failure while on the TPK going about 85 or so. It was over before i even knew what happened (took the HG with it too)

 

SO...how is the WP?

 

Matt

Did they get all of the air out of the system?