Whining Noise
An independent Mercedes dealer, my local mechanic, and Autozone said it is my Power Steering Pump. All said so just from observation and no tests. I went back to my local mechanic after getting prices to make sure, and he took belts off and still came to the conclusion that it was the Power Steering Pump for some reason.
Mercedes-Benz of Orange Park said it was my A/C Compressor, and another independent dealer said the same. They both used the "ears".
My friend also told me that Tire Kingdom does free diagnosis, so I told them the previous statements, and they took it right back in the garage and took off the belts and came back and said that they spun the pulleys and thought the Tensioner Pulley was acting funny.
The symptom is a very loud, distinct whine that can be heard from around the corner. My roommate can hear me from inside the house when I am pulling in. The only thing that factors into the noise are RPMs, which makes me very hesitant to say it is the Power Steering Pump and A/C Compressor. No sound difference in turning the wheel (unless it's all the way to the full extent, which sounds like a piston going off or a hiss), and the A/C being on or off has nothing to do with it. Only RPM. I have already changed my Power Steering Fluid with no results, too.
Any ideas? I'm sure this has more to do with the transmission since it is automatic on an incline, but when I go up a hill, it kicks up to about 2000-2500 RPMs before switching gears which makes it really loud/embarrassing!

Thanks!
They can be had on E bay for about 10 bucks.
A long handled steel screw driver to the ear should determine it too. Make sure you hear it yourself for your own piece of mind. After all you will be paying the bill!!
Interesting to hear which mechanic has got it right !!

Let's hear what the car said. I would suggest you video record with audio that whining sound under the hood,.... post it on YouTube and provide link here.
I'm sure someone here is good at identifying whining sounds,..... the only whining sound I'm good at identifying is the whining sound coming from the wife!
Last edited by SunnyRayToronto; Feb 13, 2013 at 12:18 AM.
Otherwise it could be the belt tensioner, idler pulley, alternator pulley...etc. anything related to the belt system could be the likely culprit.
Like someone above mentioned, get a mechanics stethoscope and check the parts one by one. If you hear any abnormal noise (clicking, grinding, skipping) on any of the parts it's time to replace it. I just got done replacing the tensioner and idler and have yet to get to the alternator pulley.

I'd say that's more annoying than my car, though 
Here's a video:

An observation my roommate made is that the tube that goes from the power steering pump to the front (next to the wiper fluid reservoir) was shaking when I put the wheel in full lock. I believe that's what that tube was, I think I recall emptying it when doing the PS fluid flush.
Sorry the video became so poor. Let me know what you all think.
Thanks!

If you remove the Poly V belt & start the car does the noise go away? That is check no one.
If the noise goes away then you find out which accessory or pulley is making the noise.
As JC suggests an engine stethoscope will help.
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If you remove the Poly V belt & start the car does the noise go away? That is check no one.
If the noise goes away then you find out which accessory or pulley is making the noise.
As JC suggests an engine stethoscope will help.
Yes, the noise undoubtedly comes from the front of the engine, and I am pretty sure from the right side (if facing the car).
By now I believe you know I am terrible at mechanics. Is it easy to remove the belt?
I just did a search on Harbor Freight Tools and found that there is actually one not too far from me. Even though I am low on money this month from shelling out for a new alternator, the Mechanic Stethoscope isn't too expensive and I have been curious to this noise for 4 months now! I'll probably head up there this weekend, or maybe even tomorrow if I find time, and pick it up.
Thanks!
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Best investigate if coolant hose needs replacing .
It will be expensive it coolant leaks & engine overheats.
Interested to know what noise is when you find out.



Just got back from the dealer, and was advised to replace it because the threads are showing on the tube.
Are there any alternative places I can purchase this? I couldn't find it on Autohaus
http://www.parts.com/parts/2004/MERC...iagram=5775066
http://www.parts.com/parts/2004/MERC...iagram=5775066
So clearly the coolant hose should now be the #1 priority over a strange noise. I was becoming paranoid the noise was a belt tensioner and that it will eventually pop, though, and with my upcoming 3 hour road trip, that's the last thing that needs to happen!
I've already observed the hose and 2 things have caused a worrisome for me. 1. In my picture of the diagram, #55, that part seems very difficult to connect. Any tips? 2. Will the coolant fluid leak out? Like I said, I'm low on funds, so if this is over a $100 fix then I might have to just walk for the rest of the month.
Right now the car doesn't seem to be causing any troubles with the semi-torn hose, and the farthest I drive in a trip is 8 miles total (around campus). The farthest place in town that I actually go to is the Mercedes dealer which is probably 12 miles there and back.
Thanks!
Yes, you will loose coolant some when replacing( not a lot ) so you will need to buy the correct MB coolant.
The hose clips look none replaceable so you will need a couple of quality generic hose clips too . Take a look where the other end is.
Another option is that you could cut out the worst of the damage & put a quality elongated joiner in , clamping it with hose clips. It will need to be done properly.
Good luck.
As far as the noise goes, I expect tire kingdom to do me well like they did last time. So that will be during spring break when I am back in Jacksonville. Expect a post around middle of March about the noise.
Thanks for checking up. Means a lot!
Last edited by DaODB; Feb 18, 2013 at 05:10 PM.
I have been noticing a vibration in my car. Did a quick search, and was terrified it might be my engine mounts. Then saw a little test and was happy to see that the engine didn't seem to move at all when I had my roommate accelerate in reverse and drive.
But, what I noticed today was there were no vibrations when I drove with the AC off. I got home and realized this, turned it on, and then the vibrations started. (Most noticeable on the Auto mode) Could this correlate to the diagnosis of the shops saying the whining noise is the AC Compressor? Or tests still need to be done considering all are connected from the belt mechanism?
Thanks
EDIT: The vibrations seem to be intermittent, most noticeable while at a stoplight. Did still feel it in neutral in my driveway, though, so thinking it has to do with the belt system.
1. Vibrate as you slowly let go of the brakes from a stop?
2. Vibrate on idle in park?
3. Vibration while driving?
4. Vibration at stoplight with foot on the brake and in Drive?
Whining noise, does it;
1. Whines when you turn the steering wheel?
2. Whines Only when steering is at full lock?
3. Whines only when you turn on the ac?
P.s. Been a long time someone new to the forum actually posted something comprehensible when asking for help. Kudos!!
1. Vibrate as you slowly let go of the brakes from a stop?
2. Vibrate on idle in park?
3. Vibration while driving?
4. Vibration at stoplight with foot on the brake and in Drive?
Whining noise, does it;
1. Whines when you turn the steering wheel?
2. Whines Only when steering is at full lock?
3. Whines only when you turn on the ac?
P.s. Been a long time someone new to the forum actually posted something comprehensible when asking for help. Kudos!!
But, the vibration is pretty prominent. a passenger has felt it before, and previous to all of the posts and observations I just said it was the Power Steering Pump. But after reading more it sounds like it can be much deeper than that.
The vibration seems to be off and on, even if I am in park I can feel it. It is nothing serious, but definitely can be felt. And the AC being on amplifies it.
At a stop light, I can feel it through the brake pedal. The steering wheel also shakes a bit, but lets off once I accelerate. So it applies to 2 and 4.
The whining noise is dependent on nothing else besides RPMs. Sounds like a supercharger, and found BMW videos that sound the EXACT same which the outcome came out to be the tensioner/idler.
Can a bad tensioner/idler cause vibrations?
EDIT: My Indy mechanic was shocked out how rough it was at idle. At a stop light I notice it at about 500 RPM. Also, let it be known that a long time ago (about a year) the shifter bushings were in "caution" from the dealer saying I needed to replace them. I have not done so.
Last edited by DaODB; Feb 26, 2013 at 04:45 PM.
Whining noise if depends on rpm then yes, the bearings probably seized.
Just got back from the library and felt strong vibrations again. Auto AC in gear seems to cause most vibrations. Auto AC in park still vibrations, but not as heavy. No AC on is very slight vibration, hardly noticeable at all.
I am still planning on getting the tensioner/idler checked over Spring Break.
Any dangers of driving the car under these conditions?
Honestly I don't care if the car runs rough... I just don't want to take the highway to hell...
Last edited by DaODB; Feb 26, 2013 at 08:10 PM.
Some code reader will not show pending codes. Only codes that throws a check engine light. A slight misfire will not throw a check engine light. Get a code reader that will show you the pending codes or go to a mb mechanic that has the STAR.
Once you find out which cylinder is misfiring, check the ignition wires for resistence. Pretty common to see ignition wire go bad and causes misfire.
Last edited by FrankW; Feb 26, 2013 at 08:15 PM.
Considering I will only have this car for 2 more years, and the value is dropping on it more and more, how does a bypass belt sound? Even though I live in Florida, I am not so sure I want to pay, what, $1500 for it!?
Let me know what you all think.
Thanks!
Considering I will only have this car for 2 more years, and the value is dropping on it more and more, how does a bypass belt sound? Even though I live in Florida, I am not so sure I want to pay, what, $1500 for it!?
Let me know what you all think.
Thanks!
http://www.lkqcorp.com/search-inventory.aspx
Actually, the new ones are about the same price!
http://www.fcpeuro.com/Mercedes~Benz...004&m=20&e=630
Last edited by syfi; Mar 6, 2013 at 02:22 PM.






