Help Please A4 Avant Fans Whistle & MAF / Thermostat

[Thomas Nevin]

Hi all and happy new year.

Have a couple of questions that if anyone can help I would greatly appreciate it.
I have an Audi A4 Avant 136bhp 2011 with 96,000 miles on the clock.

I have noticed the fans whistle slightly inside the car at certain fan speeds.
Googled this already but still not sure what could be causing it or more importantly how to stop it.
Is anyone else having this issue?
This may have started after the car was recalled for the Air Con thing in 2018 but I can't remember whether or not this is the case.

Secondly, my temperature gauge is dropping while driving (sometimes) to about 70 c.
It used to sit steadily on 90 c but now its dropping intermittently.
Ran a scan with VCDS and it did show that there is an intermittent fault with the mass airflow sensor, could this be causing it or is it more likely my thermostat stuck open?

 

[daleyarrow]

I used to have a fan whistle at certain speeds coming from the passenger footwell...turns out the last service hadn’t secured the filter box back together properly and it was whistling air out. Might be worth looking at if it’s coming from that area?

 

[Thomas Nevin]

I used to have a fan whistle at certain speeds coming from the passenger footwell...turns out the last service hadn’t secured the filter box back together properly and it was whistling air out. Might be worth looking at if it’s coming from that area?

Hi, Thank you for the speedy response. Much appreciated.
The noise that I have noticed is coming from the fans on the central console but I will definitely take a look at that though and see if I can find the same for the fans I am hearing.
Thanks again !

 

[Mike B]

Assuming you mean the interior fan not the engine fans it may be some thing stuck in there .It would be worth checking the filter and cleaning any debris out.Often you find the last one in there hasn't correctly fitted the filter which can be fiddly.The temp thing is bound to be the stat; that sounds like the classic sign.Is the heater slow to kick in?Thats also a sign in cold weather.I would change the stat and if there is still a fault with the MAF it may need cleaning or changing

 

[Thomas Nevin]

Assuming you mean the interior fan not the engine fans it may be some thing stuck in there .It would be worth checking the filter and cleaning any debris out.Often you find the last one in there hasn't correctly fitted the filter which can be fiddly.The temp thing is bound to be the stat; that sounds like the classic sign.Is the heater slow to kick in?Thats also a sign in cold weather.I would change the stat and if there is still a fault with the MAF it may need cleaning or changing

Thanks for that Mike. Yes I mean the interior fans. I’ll try get to the filters over the weekend. I suspect (but I’m not 100% certain) that this only started after Audi recalled it for an issue with the aux heater / ac unit last year.
I’ll replace the thermostat and get a can of MAF cleaner too for good measure.
Just wanted to see if anyone had the same issues.
Cheers again !

 

[Jon B]

I have the same engine with 85k on the clock. In temps below 10 degrees,
My temp needle will start to drop below 90, especially at speeds below 60mph and when putting no real load on the engine.

The manual says it’s normal and my car has done it ever since I bought it at 40k miles. I still get over 50mpg in cold weather, so I don’t think it is causing the engine to run richer to compensate.

 

[Thomas Nevin]

I have the same engine with 85k on the clock. In temps below 10 degrees,
My temp needle will start to drop below 90, especially at speeds below 60mph and when putting no real load on the engine.

The manual says it’s normal and my car has done it ever since I bought it at 40k miles. I still get over 50mpg in cold weather, so I don’t think it is causing the engine to run richer to compensate.

Hi Jon,
Thanks for the reply.
I bought the car last November at 72k miles and I don’t remember it happening last winter (that’s not to say it didn’t happen)
I’m still getting 54 - 60 mpg on my daily commute so no complaints there but I just want to make sure I stay on top of things with this car as it’s the first nice one I’ve ever had.
Thanks again for the reply.