My friend is having a problem with her '93 Impreza. Sometimes there is no heat, and other times it works normally. Could the thermostat be stuck open or something like that when there's no heat? I really gotta find out what's going on and fix it for her cause it's been around 15-20 degrees around here lately. Thanks

bump, anyone got any input as to what is going on?

Is there air trapped in the system? Have you "burped" the cooling system?

If it were a thermostat problem, she should notice the car running hotter than normal and/or overheating. Check and make sure the coolant is up to normal level. If the fluid is low, you'll not get heat.

 

If the fluid looks normal, proceed with the "burp" that was mentioned. Search this site and you should find some explinations of how to properly do this. I recently changed the thermostat in my 95 Sube, only to have overheating/no heater problems a week later. I thought maybe the water pump, but it didn't seem that wold be it. The fluid level looked to be normal, as I thought maybe I'd had a leak from my thermostat swap. No noticable leaks. My upper radiator hose was hot, but I couldn't feel movement inside. I squeezed it, and my radiator gurggled (the cap was off) and the fluid level dropped. I did it again, then proceeded to fill the radiator, periodically squeezing that upper radiator hose to gurgle out air.

 

I'm sure this method is the wrong way to properly get air pockets out of your cooling system, but my car has not overheated since then. This is my first Subaru, so I don't know if this whole air and "burp" business is a Subaru issue--I'd swapped out thermostats and flushed/refilled radiators on Detroit steel for years and never had an issue like this. The Subaru dudes and dudettes here can probably shed a lot more light on the situation than I can.

I have seen. The only harder vehicles I have done were Greyhound busses.

With the motor lower than the heater abd the thermostat on the bottom one has to be fairly careful to get all the air out.

I haven't really had a problem with it myself but I am pretty fussy about making sure all the air is out. After doing it once next time I'll modify the system.

Yeah, I asked her if it's been running hot, and she said that it's been fairly normal, if not a little lower than usual. I checked her coolant level last night and it was low, so I told her to throw some water in there and tell me if it helps any.

 

Thanks for the replies