engine fan noise
Thread Starter
Banned
Joined: Apr 2019
Posts: 77
Likes: 8
engine fan noise
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?
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?
Super Member
Joined: Jan 2021
Posts: 557
Likes: 204
2021 Mercedes GLB250 4Matic
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?
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?
P.S. I just noticed that you have a diesel engine. There might be a difference between engines in fan running logic.
Last edited by Vladimir Livson; Dec 9, 2021 at 10:47 AM.
Thread Starter
Banned
Joined: Apr 2019
Posts: 77
Likes: 8
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....
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....
Super Member
Joined: Jan 2021
Posts: 557
Likes: 204
2021 Mercedes GLB250 4Matic
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....
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....
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?
Thread Starter
Banned
Joined: Apr 2019
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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
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Super Member
Joined: Jan 2021
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2021 Mercedes GLB250 4Matic
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.
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Senior Member
Joined: Jul 2021
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2021 Glb35 AMG (2013 GLK 350)
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
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
Newbie
Joined: Feb 2023
Posts: 9
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From: Warwickshire, UK
Glb220d
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.
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.
