Odd Hum for 2 minutes after shutting down
 

My wife just picked up a 2014 E350 with most of the goodies. It replaces her previous E350 and I have a 2012 E550c.

I noticed after we brought it home and shut it off in the garage there is an odd hum - quite loud - I can even hear it a bit through the walk in door to the garage.

The sound is coming from somewhere in the engine compartment area. I haven't timed it but it's a least a couple of minutes then it stops and silence.

We have never noticed this sound with the other MB's - anyone else have this experience with 2014 E350.

Thanks all

I believe that noise is the LED fans at the heat sink. It think it is totally normal, as well as annoying.

Yep that is the noise in my car, too.

Agreed... Same in both 550s

Thanks all - I appreciate your speedy feedback - and I agree it is annoying.

Ahh, so the LEDs are a solution to a problem that didn't exist, all in the name of vanity. We now have headlights that require cooling as if they're a DLP projector bulb. What this means is that if the cooling is ever inadequate, the lifespan of the LED will be lowered. Not to mention, a whole different set of moving parts designed just to keep the LED from melting.

Seems like a good idea!

:word: It went from "solutions to problems you didn't know you had" to problems from solutions we invented. Kind of like the electronic oil dipstick "fix".

I'm a huge MB fan and have continued to tease my father (in his 60s) who *****es and moans about all the complicated **** on mercedes these days, but I must be turning into him or just another old man.

I love the S-Class, but I find myself longing for a 212 as a replacement because it can be had without the complicated suspension bits...

I love the look of the facelift, but if cooling fans are required to keep LEDs (which, by their very nature, should be more efficient than anything they replace), I will happily pass.

I've owned MBs from the late 70s until the late 2010s and this is just ****ing crazy talk.

Since the LED lamps don't put out any heat forward to keep the lens warm they may be using the fans to move heat forward to melt ice, etc. I have heard that the LED headlamps in some cars have icing issues. Okay, if you live in a warm climate.

There are actually three fans in each LED headlight....and they do run for a while after the car stops. I don't even want to think what a replacement headlight assembly costs :)

I don't think that is the hum you are talking about. Only reason I say that is that if I lock the car, the hum shuts down. If the LEDs are in fact "hot," I would expect that the fans would continue until the units are cool and not turn off when I lock the car. Also, I get this humming first thing in the morning.

I figure that mine is for the air suspension, but I am guessing it is not as others without air suspension are reporting the same noise.

None of the OPs cars have Airmatic so that is obviously not it.
Airmatic only hums when it is pumping air. So that might explain the humming in the morning. When you get out of the car it should "queef" or "fart" to release air, it should not hum.

Airmatic does not make a noise like this and yes it burbs, hisses, farts as it levels itself after stopping. These E class cars continue the tradition of being the noisiest cars on the planet. My E500 took some getting used to and now I hardly notice all of the noises they make. Passengers are always curious with the sounds, especially the gas noises when we walk away, as if it is giving us the old raspberry tongue.

I was thinking it was related to the compressor. The farts are obvious.

When I opened the door this morning, the hum started right away. Why would the LED need cooling right away? Also, why does the hum not appear even when the headlights are on?

My stealership said it was the fans on the lights and mine come just about anytime for any reason. I was in the garage last night and the car had not moved in hours and the fans came on just because I walked by it. And so many people say I'm cold hearted?!?!

I notice that if I open the door to get something inside the car it'll set the fans off...

Everyone loves a good humming in the morning, even when she queefs..:D

Since I read this thread, I paid attention to my 2014 E550 (which has the LED headlights)...

After I stopped the car in my quiet garage, I tried to hear the LED headlight fans. On mine, the fans were not that loud...I had to put my head so close to the LED headlight that my ear was almost touching the housing, until I heard some fan noise (sounds similar to those small fans inside a laptop computer.)

On a side note, the 2014 E-Class (both Xenon and LED headlights) no longer needs to have the headlight cleaning system.

^ dazzle oncoming traffic? what the? So, I guess when it is raining out at night we should turn our lights off, so we don't dazzle that oncoming traffic? Okay....

And my car "dazzles" everyone ... just by being. :naughty:

I know last post was several months ago but anyway... ref: post by Konigstiger 10-07-2014, 03:53 PM

https://mbworld.org/forums/e-class-w...2-sedan-9.html

LI82.10-P-059909 SEPT14 – 207, 212 with full LED headlamps (640) as of 2014 noise from headlamp area with vehicle parked and ignition off. Headlamp cooling fans may run for an extended duration due to latent engine heat or other ambient temperature related factors. If headlamps are fully functional and no fault codes are found this is considered normal.

LED headlights not only offer brighter lights, but also a much longer service life than bi-zenons (approx. 10 years vs 4 years average for bi-zenons). A little humming noise from cooling fans seems like a very minor issue to me given the added benefits of LEDs.

I do believe this as something to do with the air condition and not the led lights.

Jury is still out on LED. It's not the lamps and there longevity that I worry about but the heat sinks, fans and other stuff that could fail. I'm on my 3rd MB with bi-xenons and have never had a failure yet.

Good that you have had no bi-zenon failures ! In the Vancouver area, I have observed a number of MBs with only one bi-zenon operating. Maybe our very moist winters affect bi-zenon lifespan ?

All of the LEDs and their attendant parts are covered for four years under the Canadian warranty for MB, whereas bi-zenons are only covered for two years.