Heater problems. blown HG? 1980 hatch

[blownchevelle503]

1980 1600 hatch ea71 top center mount starter, etc...

 

my radiator fan control switch went out, I have a small leak in my radiator drain cock. I have rigged the fan to be constantly on, or constantly off, I keep the level to where the little sticker indicates it should be. and still I get luke warm heat for about 3 minutes, then it goes cold on any mode, recirc, vent, heat, and def. If I wait another 10 minutes it does the same thing.

 

before this all happened, the heater worked great, my temp gauge would never get above a little below the 1/4 mark, and would always be warm once it reached that level on the gauge.

 

now with the radiator fan on constant, it gets to right at 1/4 with no steady heat.

 

with the radiator fan off and while the vehicle is moving, it does the same thing.

 

if I'm sitting in a parking lot with the car idling, it will get to 1/2 on the gauge and start spewing steam and water.

 

so my questions are...

 

is this problem due to the fan ctrl switch, and the drain cock?

 

is there a different temp thermostat I can put in to give me better heat?

 

I think I have a 190* thermostat in right now.

 

I plan to order the fan ctrl switch, and drain cock on the 4th, and install them on the 5th. if I need a new thermostat, I'd like to do it while I have the cooling system empty.

 

 

btw.. when the temp gauge is at normal operating range for my car, all of the hoses, heater hoses included, are all warm/hot.

 

also, I think I might have a small leak in my head gaskets, my brand new plugs have rust colored substance on the porcelain. I did a compression test on saturday, I have

 

1. 115 psi

2. 125 psi

3. 140 psi

4. 115 psi

 

thank you all for your input in advance!

 

Kyle B.

[GeneralDisorder]

Either the heater core is plugged, the heater control valve is plugged (or not working), or the coolant level is too low.

 

Blown HG will not cause the heater to stop working.

 

190* is the proper thermostat - get one from the dealer and install it.

 

GD

[blownchevelle503]

after going under the dash, and checking all the vents and vent tubes, I found that on defrost, the left vents blow warm air, while the right vents do not. which I find weird since they are all connected to each other.