Help for C4 owner

[Rob]

Any ideas for this guy?

C4 Heater Problem

 

[tonylong]

Hmmmm can't post reply after clocking on his link.

 

[Rabbit]

Hmmmm can't post reply after clocking on his link.

Ditto..............

 

[Florida Guy]

You didn’t indicate if in the heat position the air is cold or if he gets no air at all.

The following is from my FSM

Check for coolant flow through the heater core as follows:
1. Check radiator coolant level.
2. Start engine and allow to reach normal operating temperature.
3. Set temperature level to full hot position.
4. Set blower speed at “HIGH.”
5. Select any mode except “OFF.”
6. Place hand close to lower heater hose. (It will be very HOT.)
7. Place hand close to upper heater hose. It should be cooler. If both hoses are hot and about the same temperature, check for restrictions in the heater core and related hoses or pipes.

But it could be one of several different problems.
A stuck door in the heating/air condition plenum.
A leaking vacuum hose to a door controller in the plenum.
There is a “heater shut-off valve” in the evaporator case assembly that prevents air flow around the heater core when the AC system is set to maximum cold. This could be stuck..

I’m guessing it is a leaking vacuum hose.

 

[five-oh]

Any ideas for this guy?

C4 Heater Problem

Not alot of info to work with, but when I had the same problem with my '93, ten minutes with a water hose and low pressure water flushing the heater core both ways took care of it. Had quite a bit of "gunk" run out, just ran the water 'til it ran clear, buttoned everything back up, topped off the coolant and voila! Problem fixed, at NO $$!