Klimaanlage bläst sporadisch warme Luft Passat B7 Bj 2011 | Posts 16+

Thank you for the tip. So, I couldn't detect any ice formation.
What I've noticed, however!

Please correct me if I'm wrong...

The thick pipe (low-pressure line) has a flow direction from the compressor to the evaporator.

The thin tube (high pressure) carries the refrigerant from the evaporator to the compressor.

The main pipe is cold for me. But... Right now, when only lukewarm air comes out of the nozzles, the main pipe becomes warm. It actually feels warmer than the thin hose.

"When the vehicle is stationary and the engine is running, the air conditioning works fine. However, as soon as I start driving, it only takes a few minutes for the air conditioning to start blowing warm air." Both fans in the engine compartment are running even when the error occurs.

"When the error occurs, if I turn off the AC for about 10 seconds, cold air starts blowing again..." That's all there is to it...

Thank you all for the tip .

"On my Passat, manufactured in 1998..."
Yes, it's older technology, with a different engine. But still, a great car...

Is it true that when I start the car in warm weather, both the large and small fans will run?
But as soon as you drive for a bit, the small fan kicks up a notch.

Regarding the problem with my Passat, I haven't noticed any of the fans switching to a second speed setting.

Do you perhaps have an electrical problem? Take a look at the wiring and measure the current at the plug.

Which plug? Fans?

Climate compressor.

Thank you for the tip.
Generally, since it's getting cold, the compressor is running... But something is causing the cooling system to occasionally fail.

I would like to measure whether the compressor turns off, but I would have to do that with the engine running... And over there, it's so narrow that the fans would literally pull my hand off.

Okay, I'm ready. Please provide the German text you want me to translate.

Thank you for the link. I'm sure I've read that more than once.

monsenseg wrote:

I would like to measure whether the compressor turns off, but I would have to do that with the engine running... And over there, it's so narrow that the fans would ;)literally

rip my hand off.

You can only approach it from below. The compressor is valve-controlled, meaning that the shaft is continuously driven by the driven disc.

Okay, great, thanks for the tip . Maybe I'll look for a workshop nearby where they can lift the car up.

It's important to know the shutdown conditions, if any exist. But you'll only be able to find that out when you get home.

Hello,
Let's revive this old thread. Did you manage to fix the error? I'm experiencing the exact same issue; I'm having sporadic problems with the warm air in my car right now.

Thank you. Nipro.

Hello!

I'm reading about this topic for the first time. I don't repair air conditioners myself because I don't have a refrigerant filling device.
I actually took the certification exam purely out of interest.

I'm surprised that there hasn't been a single word mentioned about the dryer.

I sometimes perform diagnostics for friends in my workshop, if they request it.
First, we'll check using VCDS, and then the next step is to check the dryer. Of course, if the air conditioner is running.
It must have a consistent temperature.
If one side is hot and the other side is cold, then it is depleted. Typically, this also doesn't generate an error message; the air conditioning system simply won't provide its full performance anymore.

Hello,
"There are no errors visible in VCDS. The measured values also appear to be normal when the air conditioning is running. However, the compressor occasionally fails to build up pressure, as described above." The dryer feels normal.

After doing some online research, I suspect the pressure relief valve on the compressor is no longer functioning reliably. I would like to know what the solution was for "monsenseg." The description is 100% accurate.

Greetings.
Nils.

Hello. I'm having the same problem. I've gotten to the point where the compressor is being deactivated by the engine control unit for some reason, but it's not being reactivated under load when the engine is idling. However, if I increase the engine speed, it will eventually be reactivated again and function normally until the engine is idling again, at which point the problem starts all over. According to the diagnostic tool, the engine and the air conditioning compressor are running at different speeds. Also, the compressor is new. It's either the compressor or the engine control unit that's malfunctioning.

Quote:

... However, I'm already at the point where the compressor is being deactivated by the engine control unit for some reason...

A smart diagnostic system, such as VCDS available here in our shop, displays the reason for the compressor deactivation. Why should the air conditioning compressor and the engine have the same speed? It really depends on how the belt drive is implemented...