parkrog

Hooked water valve up to car wiring harness and activated by vagcom and by heater on "high" also. Was not operating valves. (physically see valve inside openings) Coils show continuity (read ohms) so not "burned out". Before working on heater gave out luke warm air. Now even less warm. Early this year heat was fine but slowly seemed to give out less heat. I am sure lines are connected properly. Water circulates and used air bleed valves on heat in and out lines to confirm flow. I suspect coils are not working or internal shaft on valves are sticking internally. I don't think I can get shafts out without ruining the assembly. Next step is to take a coil off with valve in place and see if it will activate. Has anyone found source for replacement coils?

parkrog

Where can you get new coils? Part number for coils? Part number for the valve assembly? Cross reference of vehicles which use this valve assembly?, (maybe a A6???) .

MP4.2+6.0

just "jumper" the water flow by using barbed connectors and some clamps? <$10. No known replacement parts I have heard of for valve blocks on a D3 other than the o rings under those dual heater connection points. $1000+ (!!!!!!!!!!!!!!!!!!) for valve block from a dealer, at least the W12 flavor. Well worth your time to jumper it flow wise. Then you would have it nailed (or not) definitively to the valve block.

If I were trying to avoid a new $$$$ purchase and you confirm it is shot, I would try to find one on eBay or similar boards, or would try to figure out if things were interchangeable as far as the guts of the thing and then swap over needed hose connectors and the like. Risky though unless you have both in hand to try a swap over using a different valve body version. From poking in the past, not sold commonly on eBay either. With part # (see next paragraph), search eBay worldwide (including uk and .de specifically, plus I would check car-parts.com and start checking wrecking yards. Many of those guys don't use eBay and such. In my younger days when I would buy stuff at junk yards, common price/rule of thumb was ⅓ of list.

You can diligence part #'s and such (and [retail] pricing...) yourself if you go on the jimellisaudiparts site. Never seen this kind of detail posted, so someone will have to do the homework.

MP4.2+6.0

I remember hearing somewhere they couldn't take a straight 12V connection; perhaps a prior post of yours.

Bangerla

I bought a whole valve assembly from a junk yard, and swapped the coils.

parkrog

A8 D2 have very similar unit with different hose connection and wiring plugs.
Might try these used coils if I can confirm its not a stuck shaft. Several D3 valve assembles on Ebay at $300. Just worried used one might develop same problem.

ltooz_a6_a8_q7

Today, it was in the 50's and I didn't feel any heat on my car even I changed the temperature to 74 degrees. I haven't checked because I didn't feel that cold.
I really don't understand why with all these valves stuck, can you just pry the valve open, remove the electrical connection and let the hot water flow manually? If it works, then fix the electrical when you have time. The hot and cold temperature is regulated by flaps.

<a href="http://www.dognmonkey.com/audi/no-heat-in-96-audi-avant.html">How I fixed my A6 heater</a>

Cheers,

Louis

parkrog

Can't pry open valve because it is pre-loaded spring.
Coils bad. Can take off cover cap with just 4 screws and confirm easily that the coils are not working. Shaft is pulled up only about 1/4 inch by magnet.
Will see about D2 coils as replacements.

ltooz_a6_a8_q7

can you post the picture of the coils? If it's a valve, it should be controlled by a motor, and a motor should have a lever to pull or push, disengage to valve from the motor, you should be able to move the valve freely? I really want to understand how the A8 is different from the A6?
The electrical must connect to the physical valve somehow. I really want to know how it works in this car.

My heater is tested and works well... lucky me...:-)

Cheers,

Louis

parkrog2

Notice: the coil shaft is only down about a 1/4 inch. Electro-magnet only raise shaft a little to open for water circulation. Shaft is spring loaded so its difficult to pry up. Don't want to damage steel. Had it out and apart and it does move up and down.