Hi All,

Since the days are getting hotter, and It is actually necessary to cool the inside of my car down a bit, I observed an issue with my AC/ Blower fan.

I have looked things up on resetting the valves of the climate control system, however this did not really help in the end.

The problem occurring is a very irregular airflow, sometimes blowing very hard, sometimes blowing very slowly. however, especially at max blower speed, you can hear the blower running at high RPM.

What is even stranger, is that as soon as I switch to recirculation mode, the airflow of my interior fan is normal again.

Curious if any of you have experiences this problem before, and have any idea on possible problems.

I came to the following most likely possible problems:

• Something is blocking the interior air intake. However, i would need an endoscope to find out...

• Faulty interior intake mass flow sensor (does the fabia even have one??)

• other suggestions very mutch welcome!

Looking forward to your help on the forum!

?

What is the outside temperature and the cars interior temperature and what temperature are you requesting?

Does the cars interior get to what you are asking for?

Outside temperature is 25C or higher when i use the AC, generally i have it set at 22C. on hot days The AC works fine though, as the irregular airflow is cold when coming out, and the inside gets cool in no time with the AC and recirculation on, and easily reaches the 22C then.

22*oC is not that much of an issue to get the temperature down to.

Obviously once reached keeping blowing cold air would bring the temperature lower so something needs to happen.

Is it set to AUTO?

Personally 18*oC inside a car is too hot for me.

2 hours ago, M035 said:

Hi All,

Since the days are getting hotter, and It is actually necessary to cool the inside of my car down a bit, I observed an issue with my AC/ Blower fan.

I have looked things up on resetting the valves of the climate control system, however this did not really help in the end.

The problem occurring is a very irregular airflow, sometimes blowing very hard, sometimes blowing very slowly. however, especially at max blower speed, you can hear the blower running at high RPM.

What is even stranger, is that as soon as I switch to recirculation mode, the airflow of my interior fan is normal again.

Curious if any of you have experiences this problem before, and have any idea on possible problems.

I came to the following most likely possible problems:

• Something is blocking the interior air intake. However, i would need an endoscope to find out...

• Faulty interior intake mass flow sensor (does the fabia even have one??)

• other suggestions very mutch welcome!

Looking forward to your help on the forum!

If you have the fan control set to 'Auto' the fan speed will vary depending on temperature change requested.

Maybe to clarify, the irregularities in airflow occur in a timeframe of about3-5 seconds, which is not not what it would do in auto mode normally.

In that case I'd be looking for a fault in the fan control module. Suggest a scan for DTCs logged.

7 hours ago, Warrior193 said:

In that case I'd be looking for a fault in the fan control module. Suggest a scan for DTCs logged.

Thanks. Any tips on a good OBD scanner?

Generic OBD scanner won't return any fault codes. I had the same issue with my mk3 Fabia, scanned the system with VCDS and found that the recirculation flap is to blame. The PN of the faulty motor in my case is 6R1 907 511 A, however I think it is also sold under PN 8Z1 819 453 B, which also seems to include the flap's housing. I've managed to disassembly it and found out that the potentiometer was full of grease (it is pretty similar like in this video). Cleaning it solved the fluctuation of the fan's RPM. However, don't forget to set the recirculation flap to the same position as the current setting on the climatronic panel, you might end with a flipped function of the recirculation button. The whole process is also described in the workshop manual. You will also need to reset the climatronic after mounting it back.