AaronCarol

I had something similar happen to me a few months back. No heat, and the engine overheating. Came to the conclusion that I had a bad head gasket because the coolant wouldn't circulate so I figured on an airlock happening. Finally I decided to change the water pump and T-stat only and leave the head gasket. It's tempting to jump to blaming the head gaskets given their notoriety. Plus I did a CO in the coolant test that turned up positive. But I am convinced that these tests don't work right if the coolant is not circulating for two reasons, 1) coolant beside the block starts to boil when it's not circulating and this gives off a gas which can fool the test. 2) coolant can actually back up into the test and mar the results. To make a long story short the water pump was the only culprit because the car is working fine now. The water pump was totally screwed up when I removed it. My recomendation is to change the water pump and T-stat both and see if that solves your problem.

I posted a while ago after having an overheating problem in my legacy. After reading and more reading and much helpfull advice from the faithful (thank you) I came to the conclusion that I should have an 'exhaust gas in the coolant' test done to to find out if despite no oil in the coolant and no coolant in the oil, I didn't have a head gasket failure. I took it to a garage and a guy brought out a test tube thingy that you put in the rad fill hole. He proceeded to fill it with the blue solution and said that if it turned green then it was a sure sign that I had a problem. It turned green. I drove home, stopping every time the overheating started to let it cool down. I parked the car in my driveway, took the insurance off and started preparing for the big job of removing the engine and rebuilding it. Three months went by before I got around to doing anything on that engine. By then I started to question if the test was faulty. It occured to me that the coolant wasn't circulating at the time of the test. It was stationary and because of that was starting to boil at the block when it started to overheat. Then I remembered hearing a whistling/ringing sound before the car started it's overheating and reasoned it could have been a water pump bearing. On that hunch I decided to just replace the water pump and thermostat only and see if the engine ran fine or if I still had problem. Well, my hunch was right, the water pump was fried, metal particles in the coolant and everthing. (Should've checked that) Long story short, the cars been running three weeks now and no problems. I'm glad I didn't jump right into replacing the head gaskets. So a word of warning, those tests don't work when you're coolant is boiling. Makes sense now but had both me and a mechanic fooled.

Only "failsafe thermostats" are designed to stay open when they fail. When looking for a replacement from an auto parts store I couldn't find one for a subaru. It looks like all engines that subaru makes though take the same picking thermostat! At least the page of engines that I looked at. Maybe a guy could find a thermostat with the same dimensions and temp range for another make that is a failsafe and use it instead. There is a thread in here I noticed of a guy that successfully used a chevy 350 t-stat in his sube.

Ok, went for one more round same result. Filled rad, from both ends, and filled reservoir. car overheated as usual. top rad hose was boiling inside, bottom rad hose cold, rad cap cold, coolant in rad barely hot. Couldn't notice any smoke coming out the exhaust pipe, and didn't notice any smell. And still no heat in the cabin the entire time.

To answer your questions: no i don't notice smoke coming out from the exhaust but there is a funny smell of burnt coolant in the air but I can't quite tell where it's coming from, it can even be noticed in the cab. Seeing as Sube's pull the coolant from the radiator via the top hose (I'm told) it is strange to me that the coolant that I observed spurting out was spurting out the bleed screw hole and not the rad cap hole, as you know the bleed screw hole is right where the top rad hose joins the rad. After a few minutes it did start coming out the rad cap hole but not to the same extent. It seemed the coolant was expanding but not circulating. In my chev 350 I can open the rad cap and see the circulation, it seems odd to me that it stays completely still in the rad in the subaru. Just to double check, now that the car is cooled down I am going to fill the rad one more time till it overflows and take it for a drive keeping in mind to look for smoke from the exhaust and I'll try to pinpoint the smell.

Think I figured it out. Did an exhaust in the coolant check and it turned out possitve. Guess I have a blown head gasket

Thanks for the tip. But I tried burping it again as per your instructions, engine running, rad cap and bleeder screw off, and I even drove the front wheels onto ramps to get the front end in the air. Then I topped up the fluid. I noticed that the fluid seemed to be expanding. Once the car warmed up coolant started to spurt up 4" out of the bleeder hole in a rhythmic action. I revved the engine and more coolant came spurting out. So what do you think is happening? Anyone?

Just humor me here but if it was just a thermostat shouldn't I still have heat to the cabin. If indeed it is stuck closed and not allowing water to the radiator it should still be circulating in the other loop and also the cabin heater block shouldn't it? Or are Subarus different.

Can somebody tell me what is wrong with my Legacy wagon? First off, there is no heat coming out of the vents. Secondly, the engine overheats to almost boiling over. I've checked the coolant level and tried burping (but not sure if I was successful). I also checked the coolant and reservoir tank to see if there was any visible oil in the coolant but there doesn't appear to be any. I noticed the cooling system did pressurize after running the engine but the radiator cap never got hot. Even though the gauge said the engine was very hot, when I removed the "cold" radiator cap I was surprised to find the coolant bubbling out of the radiator was also cold. Can somebody explain this to me?