legacyofbrutality

Installed the new thermostat, refilled coolant and burped it. Took it for a test drive, running it easy and hard a bit for about 10 miles. I then let it set and idle for a good 15 mins or more after the drive. I still have really good heat and noticed no issues at all. The gauge hasn't risen over the half mark at all, so hopefully the problem is resolved now.

I squeezed the spring with a pair of pliers and it released enough pressure for the valve to release, that's the only way it would move. I thought maybe getting it unstuck that way, it might help it to work again somewhat... but I put it back in the boiling water and nothing, still stuck closed. It didn't looked really corroded or anything, so I'm not exactly sure what the deal is with it.

No restrictions in the radiator, but definitely a bad thermostat. I took the old one out, put it in a pot on the stove with a thermometer. Went well past the 172 degree point and never opened. I let the water fully boil beyond 200 and it doesn't open even the slightest. I'm going to pick up a new one today, reinstall and hopefully that will solve the problem.

I'm going to check it over way more closely this time around, definitely not ruling it out. It came in a cardboard box, strapped with another piece around it, no foam, peanuts or anything like that in the box.

That's kinda the game plan at this point... change the thermostat, in which case I'll have to drain the coolant anyway. Yes, radiator arrived new yesterday and in a rush I installed it without thinking to check it for anything obstructing. Definitely possible. I guess after draining to install the thermostat, I can then check it by running some water through it. From there, I will try the radiator cap... I just want to try and isolate the problem by doing 1 thing at a time.

Trust me, I've read so much on this it's driving me crazy. I registered here as a last resort for possible help, because of so much conflicting stories, solutions, etc. I can easily drain the coolant and refill it that way, BUT is that necessary? Can it not be burped/bled after the fact if I didn't fill it that way to begin with?

I understand about how the ex. gases get pushed into the coolant, but wouldn't this cause an overflow, at least into the tank or pressure forcing coolant out of the neck with the rad cap off? If so, I have none of that to speak of. As far as heat inside the cabin, it's great. I've not experienced a loss of or any change really. Once it's warmed up, the heat blows warm as it should. Even on the test drives where the temp raised to 3/4, at one time almost to the red as I pulled off, the heat inside never changed. In fact, I kept it running full blast the whole time driving, hoping that might keep the temps down a bit and/or circulate the coolant more in case of air.

Yes, I plan to buy an OEM if I do decide to replace it. The more research I do, the more I think that it is stuck closed. As I mentioned, the lower radiator hose never warms up at all. I mean it stays completely cold after idling for 20+ mins, even after the gauge indicates that it's overheating coming back from a test drive. It's cold as can be.

Mileage is 170K. I haven't ruled that out, but there are no real signs of a head gasket problem, at least from what I've gathered. Old coolant had no oil residue, definitely none in the new that I put in (yet). Same with oil, no coolant mixed in it. Visual inspection at the gaskets, there is no signs of seepage. There's no pressure build up with the rad cap off when you rev the motor or anything.

Nothing is modified from the factory, so no hoses or anything are blocked off. Both fans come on like they should.

So here's the scoop, I just replaced the radiator in a 2002 Subaru Legacy base model with AT. The original OEM radiator cracked just below the top neck, causing the car to start overheating, hence the replacement. I replaced it with a parts store replacement radiator, not an OEM one. I didn't change any hoses, thermostat, etc., just the radiator and a coolant fill. I know, I probably should've done a new thermostat too, but needed the car back on the road asap, which now hasn't happened. I filled the radiator through the fill neck, topped off the overflow tank and let the car idle up to normal temp. I made sure to fill it until it didn't draw anymore in. First test drive, within a mile or so the gauge starts climbing to 3/4 or so. Pulled over, let it cool down and limped it back home. I did some research, thinking that there might be air locks, so I tried various methods of burping - squeezing the upper and lower hoses while running with the radiator cap off, letting the heat run full blast while do so... nothing seems to help. I'm not sure if there is still air in there or if I have a problem with the thermostat possibly? I'm solely basing all of this off the stock temp gauge... At idle, the car never goes over the 1/2 mark. It only starts to soar when you take it for a drive, and it goes up within a mile give or take. The heat is very hot and working great, the lower radiator hose never warms up at all??? Not sure if it should? Take into consideration that it's in the lower 30's outside. Both cooling fans kick on and off at idle as well. I've not seen it draw anything from or overflow into the tank at all. The coolant is not boiling, it's not shooting out of the neck or doing much of anything with the rad cap off. I've tried just about everything to make certain there is no air trapped. So I'm kinda stumped at this point... My next plan of action is to drain it all and replace the thermostat, but I thought I'd seek some advice before doing so.