jeffrey2

I always thought these cars were superb in cold weather, but mine has begun making some type of grinding sound from the HVAC when I turn the defroster on in the cold. It lasts for a moment, then stops. No weird smells, just a noise.

It sounds like the unit is switching to the defroster, but cannot for some reason.

I have searched the forum, but I don't believe it to be the same as others I've read as mine isn't a chirp, but more a grind...like an electric motor that struggles and gives up.

HELP!

JayDee4711

I observe something similar, except I would describe the sound as whining rather than grinding. Sounds like a mix between the fan blower bearings working on their last mile and air being pressed through a gap somewhere in the heating system.

It must be pretty cold for this to occur, maybe 20F or less, and it goes away within a minute or two, or if I play with the air distribution or something else in the HVAC system. So I decided to ignore it until other issues pop up.

Is that what you are seeing?

jeffrey2

YES YES YES. What is it? I don't believe it's the circuitry as others say. It sounds like a gear is broken on the diverter and becomes present when it's called to divert air to the defroster.

I'm curious if it's something I should fix or if it's something I should just...well ignore.

JayDee4711

Today was the first time I heard it with the engine off and the HVAC in Rest mode. It does seem to depend on the blower speed (which is quite slow in Rest mode), and is definitely mechanical rather than air being pressed trough a gap.

I toggled Rest on and off a couple of times, and the noise was there maybe half the times it was running. The other times, the blower could be heard at what I would call its normal volume - i.e., rather quietly. Seems like the blower is approaching its last leg.

Does anybody have experience with lubing blower bearings? Is it worth the effort, or is the hassle of getting at it big enough to justify replacing it outright?

E55AMG05

I have the same problem right now and I always had. It will get worse trust me. I own a 2005 E55 AMG. The way I get through the winter now while driving in severe cold weather is wearing extra jackets socks, gloves and boots. I stay away from the heating system in the HVAC. I crank the sun roof up a little so I don't get fog on my windows. THE STEALERSHIP diagnosed the problem of the noise and gave me a heart attack price repair estimate. My car runs perfect and the response is just excellent. That's all enough I need. So I stay away from the AC I forgot what the problem was. I'm sorry guys I don't remember the problem that the slealership found about the noise from the HVAC. All I do know is it'll get louder Louder LOuder LOUder LOUDEr AND LOUDER!!!!

jeffrey2

Love it, didn't get it at first. Dunno if I can handle it. I don't think it's the blower since it's momentary...let's hope someone can give an answer so I can fix it.

06cls55amg

its the bearing on the blower motor, pull the motor out add some grease or oil to the bearing, she will be quite again. do a search its been discussed a lot.

https://mbworld.org/forums/e-class-w...-ac-fan-2.html

E55AMG05

How about the idler pulley that thing is squeaking like its in pain. Can I use the 3 in 1 oil sae 20 on the divider of the idler pulley? Only the black plastic squeaks not the metal one.

E55AMG05

Hahaha thanks I love it when ppl liie u represent me

dbworld4k

+1