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2003 ML350
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7 Posts
Discussion Starter #1
Hi,

Since yesterday i have started noticing a subtle chirping / whistling noise coming for the engine compartment.
I first thought it may be a belt but it is not happening when the car is in neutral and i rev up the engine, only when in gear, after i reach about 30 mph the noise goes away.

I recently had the center shaft bearing and the power pump replaced.

Not sure what this could be, it really sounds like a belt but would it make sense since it only happens when driving?

i am currently on the road and have 300 miles to drive back home on friday, i hope i will not break down

thanks for any input,
 

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2003 ML350
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7 Posts
Discussion Starter #2
and by the way, while the car usually sleeps in my garage it has been outside and driving in snowy and wet conditions lately.
 

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1999 ML320 Elegance, BMW R1150RT, SAAB 9-3
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282 Posts
one possibility would be the ebox fan.
search on the forum for ebox fan.

would not apply if your chirp is directly correlated to vehicle speed. (afaik the engine does not know if the car is in gear or not....) you may need to spend a bit of time testing till you figure out exactly what it takes to make it chirp....then report back here to the experts (not including myself in that group)
 

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2003 ML350
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7 Posts
Discussion Starter #4
i just went for a quick drive, the noise is definately not related to the enigne speed but to the car car speed, and goes away over 30mph. Applying the brakes does not make a difference either, basically as long as the car is moving between 5 and 30mph the noise is present. I am starting to think it may be a wheel bearing, or maybe a worn axle.
 

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2001 ML430 Sport bought in very nice shape despite 156K miles in August 2010
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540 Posts
It may be as simple as something lodged between the rotor and the dust shield. It happens. It would be localized to one wheel, of course. Depending on how fast the car needs to travel to hear the noise, you may be able to pick up which wheel is the source by having someone drive by you at the minimum speed required. Alternatively, just isolate which side its coming from and remove both wheels on that side.

Have a good look with a flashlight behind the rotors. You'd be surprised what can wind up lodged in there. While I'm not saying that's the problem, bad cv joints tend to click and bad bearings tend to howl. Birds chirp, and so do things stuck between the dust shield and the rotor.
 

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2003 ML350
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7 Posts
Discussion Starter #6
Thanks for your input, i sure hope that is the reason for this noise. The problem is i am on a business trip staying at the hotel without any tools, and it is snowing bqdly so i can't really diagnose much.

I am just paranoid about drving back because the last time i came home from the same customer i broke down in the middle of nowhere. I hope it wont happen this time.
 

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1999 ML320 Elegance, BMW R1150RT, SAAB 9-3
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282 Posts
you likely want some good technical support. sorry cant offer that but some logistical/planning support maybe. you appear to have 3 options ( hopefully more when the experts get up tomorrow and read your posts.. :rolleyes:)

1/ jack up the car one corner at a time and try spinning the wheel- hoping to at least id the corner. then remove the wheel.... and take a look (buy a 5$ LED flashlite for this exercise). if looks promising buy the minimum tool set to take off the caliper and rotor.

2/ take it to a nearby garage before you get stranded for a diagnosis :surrender:

3/ take a chance and drive home - maybe think about getting AAA or similar before you leave . and also maybe use the internet to search all indies and dealers along the route between where you are and where you are going....

normally it is not a good idea to depart on a long voyage with known vehicle problems - shades of 'grapes of wrath"....
 

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2001 ML430 Sport bought in very nice shape despite 156K miles in August 2010
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540 Posts
reno,
Unhofliche_Gesundheit makes a very good point.
If you can find an indie mechanic or even a dealer where you are now, it would be worth having the noise checked before you drive home. Its worth a bit of time to be sure that there is nothing serious going on, and maybe they find its something cheap & simple.

Driving a long distance in bad winter weather may be too big a roll of the dice.
 

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98 ML320, 01 S500, 15 GL350
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587 Posts
My experience of avoiding stranded in the middle of nowhere: Do not stop at middle of nowhere (especially rest center). Always eat and fill up gas at a big town. You always can get help there. Most of the troubles happen when start the vehicle.

I have similar chirping sound when in raining days, was told CV joint leaking with water inside, a case won't get stranded.

Wish you get home safely!
 

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2003 ML350
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7 Posts
Discussion Starter #10 (Edited)
So the day after i posted this, the noise went away, and came back on the day i was driving these 300 miles back home. At this point i could no longer have the car looked after so took a chance, drove home and luckily made it without a problem.

The car was then parked for a while and yesterday i finally took it to my mechanic to have him take a look, and he told me it was my front drive shaft which was going bad. I asked him for a quote and since he wanted $1000 ($750 for the part, new) to replace the shaft i told them i would think about it.

Then I did some research on-line and found a refurbished part on ebay which i am planning on buying and installing myself.
My only concern is that on this forum, people with failing drive shaft seem to have grinding noise and vibration as symptoms rather than light chirping noise.

Could it be a false diagnosis from my mechanic or do these shaft also make such noises at early failure stage?

thanks again for your feedback.
 

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05 ML500 SE
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Might be nice to have a second opinion, even if just to confirm the honesty/aptitude of your mechanic.
 

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2001 SLK320, 2004 ML500
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2 Posts
So the day after i posted this, the noise went away, and came back on the day i was driving these 300 miles back home. At this point i could no longer have the car looked after so took a chance, drove home and luckily made it without a problem.

The car was then parked for a while and yesterday i finally took it to my mechanic to have him take a look, and he told me it was my front drive shaft which was going bad. I asked him for a quote and since he wanted $1000 ($750 for the part, new) to replace the shaft i told them i would think about it.

Then I did some research on-line and found a refurbished part on ebay which i am planning on buying and installing myself.
My only concern is that on this forum, people with failing drive shaft seem to have grinding noise and vibration as symptoms rather than light chirping noise.

Could it be a false diagnosis from my mechanic or do these shaft also make such noises at early failure stage?

thanks again for your feedback.
I've also had a similar "chirp" start up on my 04 ML500 last week. Closest MB dealer being 100 miles from where I'm at for the time, I took it to a local independent shop for an inspection. They also indicated that it was a U-Joint on the front drive shaft. No vibration or grinding noises, just that "chirp"... vehicle speed dependent. I did find a new replacement at Driveshaft Specialist Inc through another thread on this forum for $475 including shipping. So, I may have to give that a try. Will let all know how this ends up.
 

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2003 ML350
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7 Posts
Discussion Starter #13
Well i finally got my refurbished drive shaft, and after struggling with the removal of the old one (screws were hard to access) i decided to take it to the shop down the street who charged me $90 to put it on.
I got my car back 3 hours later and the noise was completely gone. total cost ended up being $300 when the first shop i took it to wanted $1000 (for a new part however).

thanks again for all the feedback and have a good weekend.
 

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05 ML500 SE
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1,482 Posts
does the noise sounds like a turbo spooling? I have a speed dependent whistle.
 

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2003 ML 350
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NO, IT IS SPEED AND TORQUE DEPENDANT - DEFINITELY CV/DRIVE SHAFT. I'M JUST TRYING TO DECIDE ON JUST REPLACING ONE SIDE, OR DO BOTH LEFT AND RIGHT WHILE I'M AT IT.
 

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Black 2005 ML 500
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1,662 Posts
That was my last issue that made me decide to sell my ML. The axle U joints/connectors are not serviceable and one needs to change the whole axle. I think it was around $1200.00 to fix it.

The chirping will only happen while driving. The MB mechanic raised my vehicle and put it in gear, while the axle was moving and chirping, he put some pressure up on the axle and the T joint chirping will dissappear.

The MB mechanic tried lubricating the U Joint, but the U joint mechanism is sealed so no luck with it. I bought my 2005 ML 500 brand new and treated it very gently and practically only used it to go to work and a long trip or two per-year, so I am surprised that the main axle T joint failed at 108K miles.

I wonder if there is a way to lubricate that T joint before it fails..


AC
 

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2003 ML 350
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7 Posts
I FOUND THE AXLES AT ROCKAUTO.COM 45.00 A SIDE + UPS GROUND TOTAL 108.00.
WHAT A STEAL.
I'VE BOUGHT FROM THEM BEFORE, MANY TIMES, AND HAVE BEEN COMPLETELY SATISFIED.
 

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2003 ML350
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Discussion Starter #19
It was neither the left or right axle, it was a center (front) drive shaft, between the transmission and the center case.

The first shop wanted $900 to replace the part with a new one. I finally bought one refurbished on ebay for $180 and had it installed for $90. Doing the work myself would not have been that hard but ideally you would need the front wheels free as you need to rotate the shaft to get to all the screws. I looked at it and decided that for $90 i did not want to bother.

The noise is now gone car has been doing just fine ever since.
 

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Ml front drive shaft repair parts on eBay

You don't have to buy a complete new shaft to fix this problem! The parts to fix the front drive shaft joints are available on eBay. Both the double u-joint and the cv joint are replaceable, just do a quick search. You can completely overhaul the shaft for about $250
 
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