AC issues

[mik15]

i am not sure if this does any good, but i always shut off the AC before starting on or shutting off the engine in order to prevent the clutch wear of the AC compressor....

[Benman]

i am not sure if this does any good, but i always shut off the AC before starting on or shutting off the engine in order to prevent the clutch wear of the AC compressor....

I be interested in hearing from our mechanics on board if that would help.

[Hy Octane]

When my AC started blowing hot air, they replaced the thermostat that controls the temp and it also fixed my boost problem. Go Figure..

[Brav]

When my AC started blowing hot air, they replaced the thermostat that controls the temp and it also fixed my boost problem. Go Figure..

Heard of this problem before.. can you elaborate which thermostat?

[Hy Octane]

Not really. It was 8 years ago and all I remember is they said it was the thermostat that controls the Climate Control unit..

[4everRS]

I'm sure it was just the temp sending unit. Known to cause all kinds of oddities.

[Brav]

My guess is the clutch is shot. I don't think you can get it separate. Need the whole unit.

Well, you were right. Clutch is shot. Getting a new compressor put in tomorrow.. 660 installeld with all necessary parts and labor. Not too terrible.

I still think I may have an issue with this temp sensor.. I think it may be the temp sensor inside the HVAC vents? it looks very strange, like a miniature metallic pipe organ, if I am thinking of the right part. Blower Motor Regulator?

[kday]

That looks more like a heat sink. For a temperature sensor, you want minimal thermal mass. For a heat sink, the reverse. I bet there are some transistors under there that are used to modulate the blower fan speed.

[Brav]

That looks more like a heat sink. For a temperature sensor, you want minimal thermal mass. For a heat sink, the reverse. I bet there are some transistors under there that are used to modulate the blower fan speed.

Yea.. I think it regulates the fan speed. In which case I need it anyway, as mine, even when not on auto, can start creeping up or down 3-4 bars!

[kday]

Mine has no trouble keeping the fan speed constant but can't seem to maintain a steady temperature. Either Audi did a terrible job with the C5 HVAC (which I doubt) or something is broken on mine that doesn't show up on vagcom.

[Chung]

My A/C compressor cost a bajillion dollars installed. That is a great price.

There is also a High Pressure Sensor (G65?) that I had to replace on mine so that the A/C would actually turn on and stay on. This could be completely unrelated since I have no idea what that sensor does.

[Brav]

I know of that switch. Its to protect from over pressure I believe.

[Brav]

Update #2.. another $320 to the bill for parts and labor, since the compressor actually gave out, and sent chunks of metal in the system. there was like no oil in it I guess.. last guy to service it was an idiot apparently. added freon only. So I need new lines, fittings, and a drier/filter. so total repair bill up to about 1k for AC. :/

[Brav]

Update #3... no one has a F***ing dryer in stock. Just some warehouse in TX and 4-5 days to order it via dealership. Tried another Audi unit and the angles wouldnt work, since its so freakin tight in the engine bay...... mechanic is hating me for this job, and for tying up his rack for 5 more days.

Anyone have any idea where I may be able to get one? PN 4B3 820 193 A - seems to be RS6-specific. Or know where I can steal a used one?

[lswing]

Shokan...

[Brav]

Shokan...

Thanks!

[kday]

A used dryer ??

[Brav]

OK, new dryer in.. temp is 38 degrees F out of vents now!! BUT.. found out my 300W small radiator fan is toast. Mechanic checked the module which was ok, and continuity test confirmed death of small fan.. which may have lead do death of my old compressor.

Of course, no one has this F-ing part either, and I will have to wait yet another week for parts. And dealer wants 450 for a fan!! Is there any other 300W audi fan I can cross-reference that will work? Anyone happen to know the PN? not showing up in ETKA.