I bought my car a few months ago and it seems like I tried out the heater when I bought it, I'm 95% sure it worked before. I seem to remember using it while having the tops off. Anyway, yesterday was the first time I really needed the heater. So the window is completely frosted over, and even if I get out and scrape it the window frosts over again.

So I turn on what should be the heat and it blows out really well but it's ice cold. I talked to some guys at work (two mechanics) and they said it's probably my thermostat since it's blowing out air but no trace of heat at all.

I need to fix this today so give me all options, cause it's dangerous to drive with how much the windows frost over.

So is it the stat? Maybe I need to flush the system?

 

If the t'stat was stuck, you'd have problems with the coolant temp, and that would show up on the guage and/or other engine cooling problems. How does the gauge temps compare to what its been running over the past few months?

Common problem on the older 4th Gens is a plugged heater core. With the engine fully warmed up, and the heater on, check both heater supply and return line for temp. If the return is cold, pull the heater hoses off near the water pump and flush the core with a garden hose.

 

My heater core went... same style set up... but broke due to the pressure (not really sure why... the pressure is minimum at most.)

If the car is cooling fine... its the heater core. They are like $60 brand new if I recall correctly... not a bad investment. Seems the seals go on them after the cars get 8+ years old, and you have to replace it anyways.

 

Just flush the heater core.

 

Ok, I changed the thermostat just because it's cheap and can't hurt to put in a new one. I'm not sure what temp my engine should run. It was running at about 180 on the temp guage and after the stat is running maybe 195. Is that about where it should be for an lt1?

 

Perhaps you removed a 160 and replaced it with a 180. Did you look at the old one to see what temp was stamped on it? It's very typical for the engine to run 10-15° hotter than the thermostat temp in general conditions. Not sure why you would have not flushed the heater core. It costs nothing to do. If you had 180° before, you should have had heat. There was nothing really to suggest the thermostat was bad, that I read so far.

 

I'm still going to flush the heater core. I've been on the website long enough to know to listen to you and Injuneer when things go wrong, it's just that the hoses have been on there so long that the clamps are going to break when I take them off and I figure the hoses will break too. I just haven't had time to deal with the hassle incase it breaks the hoses and clamps. I'm going to flush the heater core Tuesday because I'm off work that day.

The old thermostat had 180 stamped on it, but since it was probably still working I'm going to keep it and use it in the summer.

 

And did you get the t'stat specficially for an LT1? They aren't very cheap (~$20).

 

Yeah I got one for an LT1, I didn't just go get any one off the shelf. It was about 12 dollars.