no heat at all

[jettabrendan]

so i have absoutely no heat, never really did. i also noticed that the temp needle goes 3/4 of the way to the hot side..it seems like it started with the cold weather. Also theres a brand new thermostat in there. the only thing i can think of is a plugged heater core or rad. Possibly a bad water pump? Anyone else have this problem?

[rallydiesel]

Numerous possibilities. I would start with checking the blending door cable. When you slide the temp control left or right, is it extremely loose or is there resistance? If you look behind the center console behind the ashtray, you will see a blue cable. Make sure it is moving the little lever as you move the temp control back and forth.

If its good, then I would move on to engine related stuff.

[jettabrendan]

yeah that all works, i reallt think that something is plugged up like the heater core... when i bought the car the head gasket was blown.

[maxfax]

With the engine running and the temp up to normal turn your heat on, but not the blower..  Both heater hoses should be warm to hot..   IF they are your heater core is most likely okay...

IS this on a MK2?  The blend door on those is a piece of holey tin (looks like swiss cheese) covered with foam rubber..  The foam rubber likes to turn to dust.. THe result is that no air is directed over the heater core and no heat in the cabin.. 

[jettabrendan]

Okay I read about that.. Someone used craft foam sheets. Looks easy but how hard is it to get at that to replace the foam?

[Naturally Aspirated]

here's a diy on the replacement

http://forums.vwvortex.com/zerothread?id=2355434

i just did it on a mk3 and i used the better part of friday night and all day saturday but I did some other stuff while in there and it was a mk3. It's much easier on a mk2

[maxfax]

It can be done without removing the heater box..  Much easier if you have small hands...  I cut the side out of an antifreeze jug coated it with glue and stuck it in there..  It may not be quite as good of a seal as foam, but it'll outlast that particular car......

[rubadubdub]

Just another idea if the others dont fix it.  Is your car fitted with an inline pressure valve?  Look at where the pipes go into the car and see if they're linked.  The valve is to protect the heater matrix from bursting and spraying under high pressure, interesting since you recently had a blown HG.  If fitted it could be stuck closed, bypassing the matrix.

Found this on the interweb as a bodge to bypass it, better still fit another one.
http://www.volkszone.com/VZi/showthread.php?t=331317

[smutts]

Just another idea if the others dont fix it.  Is your car fitted with an inline pressure valve?

Yup, been there, done that, fortunately it isn't too hard to replace them, but I think that the kit might not be available now. They used to be £23 or some such.

5/8 to the hot is where both my mk2 GTD's sit, which I assume is normal. So 3/4 is a touch hot, but swapping the glowplug and temperature sender wiring might show up a duff sender. The later MK2's use the same type of sender for both so it's a plug and play..

That's the easy ones, off under the dashboard else. Have fun.