Blower Fan Drone on Merc ML270 (W163)

[kceire]

Guys,

There's a massive drone noise coming from the cabin when the blower is on in the jeep. If I turn the fan speed down, the drone remains.

If I turn AC on, the drone goes away.

Really annoying.

Anybody any experience with this?

 

[andy27168]

Hi,
Is the noise still there when you press re-circ?
If it was mine I think I would initially remove the pollen filter and see if the noise goes.
Changed a pollen filter in a Mercedes ML 163 recently, very easy and straight forward, U tube video below showing a how to.
[YOUTUBE]eavoaKfXZbc[/YOUTUBE]

 

[kceire]

Hi,
Is the noise still there when you press re-circ?
If it was mine I think I would initially remove the pollen filter and see if the noise goes.
Changed a pollen filter in a Mercedes ML 163 recently, very easy and straight forward, U tube video below showing a how to.
[YOUTUBE]eavoaKfXZbc[/YOUTUBE]

I'll click the re-circ tomorrow and update.
Only changed the pollen filter about 3 months ago so it should not be clogged up already but I'll double check to confirm.

 

[kceire]

Noise still there when re-circ turned on.

 

[andy27168]

Hi,
After reading that you had recently changed the pollen filter I have thinking about this and am wondering if you have fitted the pollen filter the right way round as the filtering medium will be "courser" on the intake side progressing to finer on the car side of the filter.
I am thinking that if the filter had got blocked or partially blocked it would put the fan under more load changing its tone, the filter may of even got wet due to blocked drains overflowing into the heater intake.

 

[Jane270ML]

Next time it's droning, lift bonnet and remove fuse box lid to check if the noise is coming from under the rear of the housing near the bulkhead.
If it is, it's the ECU cooling fan.

A bit awkward to remove but not out of the realms of an average car DIY'er.

I think it draws air from the cabin through a piece of foam sandwiched in the bulhead cable route hole. Mine was filthy, binned it!

Mine still drones, even after cleaning it, especially when it's very warm under the bonnet - put AC on for a few minutes and it clears.

 

[kceire]

I'll try both of the above this week. Thanks guys.