C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

front side of engine whine & knock c240

Old Jul 6, 2009 | 02:40 AM
  #1  
hollik's Avatar
Thread Starter
Newbie
 
Joined: Jul 2009
Posts: 11
Likes: 1
From: Seattle, WA usa
2003 C240 automatic
front side of engine whine & knock c240

Hi all,

First of I have an '03 C240 automatic gearbox.. with 89.000 miles.
Fresh engine oil Mobil 1 , 5W30.
Fresh transmission oil by MB.

2 weeks ago my powersteering started making whining noises, checked the fluid, topped off and sound went away, the fluid level is currently normal.
(so I don't really suspect the PS pump at this moment in time)

Now there is a sound when my engine is cold mostly, like a whine and soft rhytmic knocking sound. (like tapping your fingers on a table 2 times per second) while idle.

It seems to be coming from the front side of the engine, the upper small pulley in the middle of the engine, or the bigger one in the middle, just below the small pulley. But with the "normal" engine sound in the mix, it's hard to locate by ear.

When the engine warms up the whine goes away and just the soft ticking sound remains. There seems to be no sounds above +/- 10 mph, but this could be due to other noises being louder then the "problem" noise.

Also when it's cold the whole car seems to be vibrating like having a badly balanced wheel, this goes away after about 2 miles of driving.

no smoke, no oil burn, plenty torque etc.....
Reply
Old Jul 6, 2009 | 07:39 AM
  #2  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
The power steering noise is typical of slightly low level - just keep it topped off. Always happens & more pronounced at full lock. A slight whine is also typical. You need to use a screwdriver as a stethescope & try & locate the noise or buy a cheap $6 car stethescope. It could be a pulley - the Poly V belt or a sticking hydraulic lifter. Carefully examine the Poly V belt for a chunk out of the rubber. I presume this soft tick is Rev dependant?

Rough running is likely a tuning issue - how old are the plugs? Check the wires & coil packs. Get an OBDII scanner - buy or borrow from a spares outlet & see if you have any stored codes - stops a lot of guessing. Have you ever cleaned the MAF?

Good luck

Attached Images  

Last edited by Glyn M Ruck; Jul 6, 2009 at 07:43 AM.
Reply
Old Jul 6, 2009 | 02:46 PM
  #3  
hollik's Avatar
Thread Starter
Newbie
 
Joined: Jul 2009
Posts: 11
Likes: 1
From: Seattle, WA usa
2003 C240 automatic
Thank you for your answer, My OBD scanner is at a friend's, go figure...

Buy anyhow I started it up this morning to have a better look at it, and I actually think it may be either the water pump or the alternator making the noise. Listen with the good 'ol screwdriver on ear on the "mechanical" bits of the engine and all seemed to be running smoothly inside...
Now is there a simple way to get the belt off?
(which seemed in good condition).


Looked at it can't really find one easy pulley to loosen....
Reply
Old Jul 6, 2009 | 03:52 PM
  #4  
hollik's Avatar
Thread Starter
Newbie
 
Joined: Jul 2009
Posts: 11
Likes: 1
From: Seattle, WA usa
2003 C240 automatic
Hi all, just did some better researching and found a way to release tension myself from the belt.

I am quite sure I have located my problem, and have included a video for you guys. I really think my waterpump is going dead on me ...
Any pointers on what I should be aware of when replacing it?
Is it something I can do myself without to much trouble?
What kind of coolant, or doesn't that really matter?

Link to video: http://tinypic.com/player.php?v=67hxfk&s=3

(I'm moderately experienced with working on cars)


For you who want to know how to remove the serpentine belt:
There is a nut-shaped part just to the left and below of the belt tensioner pulley, put a wrench with a socket on there and rotate counter clockwise, this moves the belt tensioner pulley to give the belt more slack and then you can remove it. (make a drawing of how the belt runs over the pulleys before you take it off, so you know how to put it back on! )
Reply
Old Jul 6, 2009 | 07:02 PM
  #5  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
I think you have the problem. Any coolant leaking through the seal? I've never done a water pump on the V6 but don't see any problem apart from access. Please only use genuine Merc coolant diluted 50/50% with deionised or distilled water.



Attached Thumbnails front side of engine whine & knock c240-c240-water-pump.gif  
Reply
Old Jul 6, 2009 | 07:26 PM
  #6  
hollik's Avatar
Thread Starter
Newbie
 
Joined: Jul 2009
Posts: 11
Likes: 1
From: Seattle, WA usa
2003 C240 automatic
No coolant leaking yet....... Thank you for the advice on the original MB coolant, part is ordered and will be in tomorrow.

(remanufactured pump since that is about 300 dollars cheaper )

Right now the coolant in the reservoir looks like plain water so someone hasn't been using the original coolant... Does not consume any coolant though, so why put plain water in it???

When I get done with it, I'll try to post some pictures for others who have this problem...
Reply
Old Jul 6, 2009 | 07:40 PM
  #7  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Remanufactured is fine - Yes they are EXPENSIVE! - The genuine Benz coolant is good for 15 years not that I would go that far - our cars don't have the chemical top up sachet in the radiator tank. It really is better & will help look after your new water pump.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 02:28 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE