Fan noise

[rafter_01]

Hi All,

I currently drive a C220 diesel (2014) and throughout the day when the car is parked and not driven, the fan goes off for quite some time unless I press a button on my car key. It will stops once I do that but the fan kicks off again in a couple of mins after. It happens a few times a day even if the car hasn't been driven. This issue never occurred in the cold weather but all of a sudden the suns out and the temp is up and the fan is losing its mind.

The fan can get loud, seems like its trying to cool down the engine due the weather!?

I can probably cope with the issue through out the day until the issue is fixed but it happened last night and disturbed my sleep (and probably the neighbours if I didn't notice it) and can now see this being a major issue for me.

What could be the issue? Is this a temp sensor issue?

Thanks in advance.

 

[Trev1964]

I had this when I first bought my Audi TT.
Thought something was wrong. Turned out the car was doing a regen and keeps the fan going after parking up to try and get it cool again.
My journey was never long enough for the regen.
Took it on a longer journey to allow it to finish doing the regen and it was fine thereafter.
May not be your issue, but worth a check.

 

[rafter_01]

I had this when I first bought my Audi TT.
Thought something was wrong. Turned out the car was doing a regen and keeps the fan going after parking up to try and get it cool again.
My journey was never long enough for the regen.
Took it on a longer journey to allow it to finish doing the regen and it was fine thereafter.
May not be your issue, but worth a check.

Whats a regen?

I have been on some long journeys in the recent months so not sure if this is the issue.

Could it not just be a faulty temp sensor?

 

[supernoodle]

It's not going to related to regen if it happens when the vehicle hasn't been driven.

Yes, it could be faulty sensor or fan controller, though I would expect that to be on a switched power, so couldn't just come on even if signal was interrupted.
Someone recently had an issue on a Vito with an intake temp that read a constant high temp that caused fan to run, but was still an in range temp so didn't flag a fault. Not sure why MB didn't go a plausibility check with other sensors. The owner noticed the fixed high temp value on the diag tool. Worth getting it plugged into a tool and checking the temps are plausible, don't just rely on fault codes.