Only had my GLB250D for a few weeks and have noticed the engine cooling fan running at fairly high speed like you would expect it to with the air-con on in the summer..........except that it is now quite cold outside and the air-con isnt exactly providing any cooling (!)
The fan seems to speed up and down quite audibly in the otherwise impressively quiet car to the point of being quite irritating, if you turn the air-con off it stops

Seems a bit pointless removing the old system of "engine driven all the time" fan with an electric one that does pretty much the same thing......it doesnt need to run all the time when it is cold
I appreciate the fan will run at a lower speed all the time the air-con is on when it is hot

It is not in the middle of a regen or anything....when that happens you certainly know it's running !

Am I alone or is it yet another "feature" that we have to live with?

 

I did not notice it on mine. Had it for a year now. Do you hear the fan from the inside of the cabin? Honestly, I did not pay attention how loud the fan is from outside. I wish they would include hood sound dampening blanket. After hesitating for several months, I finally ordered one from Aliexpress. Have to wait a month to get it. Will see if it makes any difference.

P.S. I just noticed that you have a diesel engine. There might be a difference between engines in fan running logic.

 

yes, you can hear it inside !!!
cant see any reason why diesel should be any different....and I cant see why it needs to run at such a high speed when the engine is cold, the aircon is not providing any cooling and the air temp is so low outside
My bonnet already has the sound deadening....maybe thats standard on a diesel....

 

You most likely right if you can hear it inside the cabin at cold temperatures.

One difference between the engines I can think of, is the fact that Diesel Engines typically have thicker walls, due to fact that they self detonate vs. spark plug detonation, thus they retain more heat. Because of it, diesel GLB's have "Residual Heat" function under "AC" button, that are not offered on gasoline versions (at least in US).
Is it possible "Res" is on and the car is trying to supply heat into the cabin when car was just turned off?

 

no, I understand what that function does ( have had it on previous cars and it runs the interior fan at a low speed to utilise the engine heat until it cools down).... no, this is the engine (radiator) cooling fan.... the one that sounds like a 747 when the DPF is or recently has done a regen

 

LOL

 

you may well laugh in your super silent electric car

the fan is LOUD.....a problem of having an otherwise super quiet car

 

Not all good and silent with fans. I have a loud noise issue with my cabin fan. It is super loud on settings 6 and 7 (like sitting inside a prop plane). I will have an appointment with dealer in 2 weeks. My suspicion is that debris like leaves, pine needles and broken acorn shells got inside. The problem started when leaves started to fall. There was another post with the same issue and the problem was debris.

From what I can figure out, by looking at the HVAC parts diagram, the cabin filter is after the blower and therefore nothing preventing debris getting into the fan.

 

well thats a daft place to put it!

 

I normally hear the fan outside with the GLB 35 after engine shut down but not inside...

Per German forum: "Diesels are louder and have a sound insulation mat... In the gasoline engine, the turbocharger sits fairly high in the front area. And the turbo gets very hot. That is why it needs different insulation mats than the diesel. These mats are aluminum-coated in the area of ​​the turbo. The normal diesel mats could overheat and cause an engine compartment fire. These are the statements of Master Mechanic."
https://www.motor-talk.de/forum/fehl...-t7104636.html

 

That is interesting. I have to do some research on it.

 

Ditto. This is of fairly high interest to me, also.

 

any updates ?

 

pleased to say the dealership replaced the fan and it is now super quiet.....either that or they didnt re-connect it

 

Became a new member to glean information on glb 220d cooling fan fault.
car I have had for 18 months with no problems until now. When the car is locked and not in use for 24 hours you can hear the fan start up from inside the house. It will just run until the battery is flat. If you catch it in action the fan will stop by unlocking the car. Last repair Friday 10th February at Mercedes Worcester. The front lower bumper wiring harness was faulty and replaced under warranty. Did one hundred mile journey on Saturday and left the car alone Sunday. Sunday evening fan came on, I caught it, unlocked the car and stopped it. Will have to start another week by phoning dealer again. There have been other issues too.
I love the car and was my retirement car costing at least 3 times the price of any car I have bought since starting driving. Very dissatisfied.