Heater problems

feel the heater hoses for heat in both hoses when the engine is warm. Might be a clogged heater core. I hope that VW did not recall yours too and install some coolant bypass that does not allow hot coolant into the heater core. After the recall is done on the VW Foxes they don't seem to have good heat anymore. :-(

Did your Jetta go through any heater core recall program?

Dave wrote:

Right. Recall fix. They installed a device that restricts the hot coolant flow to the heater core. Its basically a differential pressure regulator. It never fixed the ACTUAL source of the problem, defective heater core couldn't take the normal system coolant pressure. The folks with the fix didn't have a potential blowout problem, or leaky core inside the car. However, the heating capability is for all practical purposes non-existent.

messagenews:rjK4j.2904$ snipped-for-privacy@nlpi068.nbdc.sbc.com...

My 89 jetta blew cold air too . Found the material on the air door had dissentagrated ?sp ( fallen apart ) . That material was some kind of close cell foam. I real PITA to pull the unit out to get to the door. Black car which the first owner left in the sun all day.

In the VW fix that I cited, the coolant still goes in/out the heater core. The heating capability is highly restricted due to lack of flow due to lower pressure. As a consequence, heating capability is virtually nil.

If you have the AC lines and heater core in same air flow box under the dash, there may be a paper separater. Sometimes this fails.

Some have coolant diverter valve that controls coolant flow to the heater core. Controlled by the cool to hot lever for heater controls in the car.

For clarity "coolant" is the antifreeze/water mixture medium used by the engine for cooling.

That being the case, check:

1. Vacuum pump.
2. All vacuum lines, especially the rubber couplings at the ends.

If you have the tools, put a vacuum source on it and see if you can draw a vacuum or not. If you can then check the vacuum pump, if not it's leaking...

from memory the temperature control flap is still cable operated from the dash lever. That said... the cause maybe the cable, lever on the box could be faulty, or the foam covering on the flap has eroded off. I think the flap is made like Swiss cheese.