I have had my 2001 Legacy for about 6 months and I have done a ton of work on the engine, mostly just to keep it from overheating. It has been overheating since about a month after I bought it. I first put a new thermostat in it and that seemed to work at first. After a few months of driving on that, it started overheating again and I had one of my friends who is a Subaru mechanic work on it to get it to stop overheating and he can't figure it out either. He is also about to get married and his fiance is pregnant so he doesn't have the time to come over to check it out and I can't afford to take it in to a shop. So I am hoping one of you great Subaru enthusiasts would be alble to help me out here with some suggestions and tips possibly. I have had the water pump changed, timing redone, timing belt changed, new radiator hoses-top and bottom, new thermostat (actually TWO new thermostats, I just re-replaced it today thinking that the problems went all the way back around to the thermostat again, but it overheated once it was up to temp for about five miles.) I noticed that the two radiator fans run constantly and shut off after turning on, so they are on and off non stop, they never really run constant. The lower radiator hose seems to be leaking due to coolant not being able to be passed through the thermostat, which is why I changed it again today. There are no signs of a head problem; no water in oil at least... I'm lost, scared and confused without my little precious car to drive around... please help...

Water in the oil doesn't happen on these engines, I believe you have the year that has the external leaks. First though did you use a oem Subaru thermostat or stant Xact stat? After market thermostats almost never work. Also these engines are temperamental about being filled, do some searching and you will find the info you need on how to fill your cooling system properly.

If filling the system properly and having the right thermostat doesn't work check for bubbles in the resivour tank that's a sight of a head gasket leak.

Thank you, I will have a look at it.

First step, as mike suggested put a Subaru thermostat in it and make sure it is filled properly.

You have to fill the engine through the upper radiator hose in order to completely fill the cooling system. Fill the engine first, put the hose back, then fill the radiator.

Okay, I looked up a few things and one thing caught my eye, it may just be what's wrong, my thermostat is upside down... when I bought the car it didn't even have one in it, so when I installed the new one, it was installed upside down and I think that is the reason the whole problem started... well, hopefully... I am about to take it for another test drive to see if it will work, with my fingers crossed!

Ugh... never mind... It still overheated and now I'm back to square one again! I wish I knew more about how cars worked...

You've done everything but the most obvious thing that goes wrong with these cars. YOU NEED NEW HEAD GASKETS! You may be lucky and you just have bubbles in your cooling system and these will cause blockages. I have had three go rounds with headgaskets on my 2000 Legacy in 230,000 miles of driving. If you continue to drive and overheat your engine you will warp the heads at minimum. My first HG leak was internal the 2nd started as a 304 code, misfire in the # 4 cylinder, the result of coolant leaking into the combustion chamber then after a few days i was dead on the side of the road. My advice have your cooling system pressure tested at least this will eliminate the HG issue. Good luck

You've done everything but the most obvious thing that goes wrong with these cars. YOU NEED NEW HEAD GASKETS! You may be lucky and you just have bubbles in your cooling system and these will cause blockages. I have had three go rounds with headgaskets on my 2000 Legacy in 230,000 miles of driving. If you continue to drive and overheat your engine you will warp the heads at minimum. My first HG leak was internal the 2nd started as a 304 code, misfire in the # 4 cylinder, the result of coolant leaking into the combustion chamber then after a few days i was dead on the side of the road. My advice have your cooling system pressure tested at least this will eliminate the HG issue. Good luck

Same thought, when you have tried all the inexpensive fixes, and nothing works, then it becomes a sound assumption that you need to replace the head gaskets. I hope you have not had repeated major over heating episodes, which will warp the heads and ruin the rod bearings. If so, you will need to start thinking about replacing the motor. Look for bubbles in the radiator over flow container, when temp is still normal. If you see bubbles, you can count on bad head gaskets.

Nice thing about Subaru t-stat is that there's no way to install it upside down. It only fits one way.

Regardless, I'd start with that, fill the system properly, and see how it does.

 

Head gaskets are a real concern at this point, but even head gaskets don't cause overheating in just 5 minutes. Overheating that quickly is due to low coolant level and/or a malfunctioning thermostat.

 

Another thing I would try since its inexpensive, and I haven't seen it mentioned yet, is a new radiator cap. Get one from Subaru when you pick up the t-stat.

Also make sure you are mixing coolant 50/50 with water, or using premixed coolant from the parts store. Straight antifreeze will cause overheating.

 

The system should hold about 1.5 gallons of coolant when full. If you mix 2 gallons of coolant you should have a half gallon left after filling the system. Any more than that and the system is not full, there is an air pocket in the engine which will cause problems with coolant flow and heat evacuation.

Yes, try the inexpensive fixes before you start thinking head gasket, it could be any number of things. There is one test that will tell you for sure If its a head gasket leak or not, it's called, block check, google it. Block check will test for hydrocarbons in the cooling system and tell you for sure if its a head gasket leak or not, it costs around $40-$50 tester and all.

Man, look at all this Subaru love! Thanks for all the pointers and tips! I've scheduled an appointment to go to the mechanic Monday at 1pm... I am disappointed that I couldn't figure it out myself, but I am just a cook, not much for anything that doesn't have a recipe : (... I will however let everyone know what the verdict is, since you are all such devoted enthusiasts and much appreciated help only makes me stronger with these funky engines! I only hope that it isn't a head problem, I paid $3k for this thing and I don't want to spend that much again just to make it run, I can't afford it, I'm not a rich man! Cross your fingers for me!!!

I wish you luck! Head gasket problems suck, hopefully it's something simple.

UGH... Time to go back to step one... finding another car. It was my head causing my Legacy to overheat!   I can't afford to fix it, replace it or get rid of it... $3k down the tube!!!! FML!!!!!!

Edited June 27, 201312 yr by tuma2.5

I had the same problem, it was the head gaskets on the 2.5 and eventually the problem became too serious to let go so I paid the $1500 or so for the head gasket job, only problem is the pressure came up after the job so the crank started making noise.  I ended up looking for a replacement which happened to be a 2.2 from a 96 or so.  The car has been mostly been running like a top ever since.  A couple possible short term fixes could be add another fan; get the best coolant, I think they make a special synthetic for high heat zones;  turning on the engine heat on a hot day may make you uncomfortable, but may wick away enough heat to keep the engine from over-heating.  I also tried Blue Devil, an expensive additive, but that did not help much and they refused to refund my money until I contacted the state AG with the complaint.  Good luck.