Blazer Forum - Chevy Blazer Forums - I found out why my heat sucked

Quote:

ORIGINAL: 95_4door
I have had my blazer for a few months now, and it is getting cold here.I haven't had real good heat since I got it. I decided to do a coolant flush and change the thermostat. Whoever changed the thermostat before tried to reuse the old seal and put a ton of gasket sealer on it. Not only that, but they put the thermostat in backwards. My heat now works great.
Just thought it was amusing when I ripped it apart.

OMG - this is EXACTLY the same thing I discovered when I replaced the thermostat in my wife`s Jimmy today! Some bonehead had put the previous thermostat in backwards! How can somebody f*** that up?!? [:@]

But unlike your situation, she still doesn`t have heat, even after I put the new thermo in. After letting the engine run for a while, I checked the heat on the hoses. Turns out that the two water pump hosesrunningto the heater core andradiator were both still cold when the engine was hot. This really makes me suspect that the backwards thermostat toasted the water pump.The backwards thermostat had been in there for at least two years (the amount of time my wife has had the truck).

What really ticks me off is that if I had replaced the thermo earlier in the week, I would have had plenty of time to also do the water pump and a cooling system flush. Now it will have to wait until later. So instead I just poured a bottle of radiator flush into the system, and I`ll let it flow through fora while before I do the repair. Any other suggestions?