TS74

Hello all - I recently purchased a 2007 C230. (67,000 miles.) When the car is driving at low speeds (like in a parking lot), the engine makes a very noticeable 'whirring' noise that continues as the car shifts thru the lower gears while accelerating, is barely noticeable in the higher gears, & returns as it downshifts back thru the lower gears while decelerating. The only thing I can think to compare the noise to is the 'whirring' you would hear coming from a toy radio-controlled car. I took it to a mechanic that specializes in Mercedes repair (no dealership within 2 hours of my town), & he said the sound is normal for the C230 engine. It does NOT sound normal to me, but this is my first Mercedes, so I don't know if he's right or not. Has anyone else experienced this? Sounds like something with the transmission or drivetrain, since it's only noticeable when the car is actually in motion, but I'm no mechanic, so I can't be sure. I love the car, but this noise makes it considerably less enjoyable to drive.*

phister

Is there any problem with the shifting or is it just the noise? You might be hearing the timing belt or maybe a loose hose causing a vacuum leak.

TS74

Yes, it almost seems like it's not shifting until it gets in the higher rpm range, like it waits too long to upshift and downshift. Kinda reminds me of what a manual transmission sounds like when you stay in one gear too long.

C230 Sport Coup

My GF's ML350 with same series (M272) engine does seem to make a whirring sound.
I can hear her coming from a mile away.

TS74

So is that normal for that series engine, or do I need to be concerned about it? The mechanic I went to says it is, but I'm not buying it. Just seems to me that a MERCEDES wouldn't be designed to sound like garbage on wheels.

OneOfaKindTrini

Sometimes mine makes a sound like that when I turn the A/C onto AUTO on a really hot day, sounds like a plane starting.

Glyn M Ruck

All V6 engine/auto transmission combos make some whirring sound which you can hear with the radio off. Suggest you listen to another one to see if yours is unusual.

samaritrey

+1 and if you can get it on video that would also help.

phister

I can hear my ac motor sometimes after I turn off the ac but leave the fan running, it makes a whining noise, but the car makes kind of a noise on initial start until it gets to operating temp.

TS74

I've heard that noise before too, but that's not the issue i'm having. The noise i'm talking about is only heard when accelerating & de-celerating, and very noticeable inside and outside the car when driving at lower speeds (especially in parking lots). It sucks because i don't even enjoy driving the car as a result.

George Fleites

My car does the exact same thing it sounds like the engine is making noise on acceleration but goes away at 30-40 mph I hope this isn't a normal sound

TS74

Yes, George! That sounds like the same thing I'm getting. VERY pronounced "whirring/spinning" noise at low speeds, disappears at higher speeds. I really hope this isn't normal either.....

W203E35

Mine does the same thing. I think that's just the way it is

TS74

Karo: Dammit! Seriously???? Have you had it looked at? I made an appt. to take mine in, but they can't get me in til next week. You think that's what they're gonna tell me, that the noise is 'normal'?

Silver C

Hmm, I dont remember having the sound that pronounced..

George Fleites

Almost sounds like a diesel engine at low speeds it's driving me nuts. I will take it to the dealership and see what they think.

Silver C

Well I hope nothing goes wrong. If I am not mistaken, the sound you are referring to only happens to me when I start my engine at cold. It will then go away after less than one minute.

Sometimes people wont even notice my car is coming from behind.

TS74

George: keep me posted - I'd be interested in what the dealer says.
Silver C: my noise is there the entire time while driving, even well after the car's warmed up. Feels like I can be heard coming from a mile away

billbillw

I have the M272 in my car and I do not hear any crazy or irritating noises when driving at slow speeds or at idle.

The ONLY noise that I ever hear that sounds out of the ordinary is the whining electric motor sound from the secondary air pump (emissions). Although it sounds out of the ordinary, it is normal for it to come on during cold starts. It only lasts for only 30-60 seconds then it shuts off.


TS74, Have you stuck your head under the hood and tried to pinpoint it? Does the sound change with steering angle/pressure? If so, you might want to see if you can pin down the noise as coming from the power steering pump. At your mileage, you might want to replace the PS fluid. Other than the power steering pump, it could be the bearings on any of the drive accessories (alternator, AC Pump), or from the idler pulleys. There has also been a report of one car having an issue with the transmission that caused the noise. I believe it was a serious problem with the tranny pump and it got worse and caused some serious damage pretty quickly. If there is any chance that noise is coming from the tranny, I'd get it looked at again pronto.

TS74

Yeah, I've seen posts of other people tracking noise down to the power steering system. I've tried turning the steering wheel all the way in both directions, but no change. Didn't get any worse. My guess was something transmission/drivetrain related, because I only hear it when the car is accelerating or decelerating in 'drive'. No noise at idle or 'reverse'. I have an appt. with an independent import repair shop next week - no dealership within 2 hours of the podunk/Mayberry town I just moved to....

samaritrey

strange my c320 is dead quite only when i drive crazy or the fan goes on to full power does it get loud.

Glyn M Ruck

A 320 should not sound anything like a diesel.

The standard whirring I'm talking about is easily drowned by having the radio on softly. About the same noise as the fuel pump. I'm being fussy. Most people hear nothing.

First place to look for whirring that should not be there is Poly V belt idlers & tensioners.

TS74

Here are a couple of youtube links that give a short sample of the noise i'm talking about. The first one is just sitting in a parking lot & giving it just a little gas. The second one is driving thru the parking lot at about 5 mph. Can anybody identify what this noise might be? (excuse the camera recording sideways....)

http://www.youtube.com/watch?v=qMUe58ZZjTI

http://www.youtube.com/watch?v=qSOG8fv5EhE

billbillw

I don't think those noises are completely normal, but I wouldn't say they are terrible either. Your car is certainly louder than my C350 though.

Get under the hood and track down the source of noise. I imagine it could be from any thing that is along the poly v-belt path. Tensioner/idler most likely. If it seems like the noise is not coming from one of the external, belt driven parts, then I would be worried that it is a more serious issue.

TS74

I'm REALLY hoping it's something simple like the poly v-belt, or an idler pulley bearing or something. Getting it looked at Monday morning, so keeping my fingers crossed! Thx for your input!