Engine clicking noise getting louder - Mercedes Benz SLK Forum

SLK R170 General Discussion SLK 200, SLK 230K, SLK 320, SLK32 AMG

LinkBack Thread Tools
#1 Old 05-03-2013
Registered Users
Join Date: Feb 2010
Location: Lancaster, California
Vehicle: SLK32 '03
Other Toys: 2002 SV650S
Posts: 52
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Thanks: 4
Thanked 8 Times in 6 Posts
(Thread Starter)
Engine clicking noise getting louder

Hi all,
When starting up, I have a noise coming from my engine compartment which sounds like a clicking or ticking. It goes with the RPM and has something of a diesel-y sound to it. When I open the hood to listen, the regular noise of the engine drowns it out. I figured this wasn't too big of a deal since it was just on the cold engine, but now it's begun to remain throughout the drive and is becoming louder. What are some things I should look for? Perhaps a pulley, the oil or the water pump?

Potentially unrelated, I had to add coolant recently. Perhaps a slow leak at the water pump, but I haven't added or changed coolant for 1.5 years.

As always, thanks for the help!
mistergoodpepper is offline  
Sponsored Links
#2 Old 05-03-2013
Registered Users
Join Date: Jan 2013
Location: Greenville SC
Vehicle: 2008 E320 Bluetec(sold 11/14), 2001 SLK 320, 2013 E350
Other Toys: 1972 MGB, 2004 Volvo V70
Posts: 287
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Thanks: 2
Thanked 37 Times in 33 Posts
Could be alternator, aircon compressor, Kompressor, water pump, valve, etc. Get a mechanics stethoscope from Harbor Freight for about 5 bucks and you can track it down.
CarolinaBluetec is offline  
#3 Old 05-17-2013
Registered Users
Join Date: Jan 2011
Location: East Grinstead, West Sussex
Vehicle: SLK 230
Posts: 18
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 3
Thanked 0 Times in 0 Posts
Hello, I am no mechanic but what you have described sounds like the problem I had last year. When I first took it into the garage they could find nothing wrong, but the noise became more frequent, and got louder, and in the end sounded like I was dragging tin cans. Boyfriend popped the bonnet with the engine running and noticed that one of the wheels would stop and restart - turned out this was the supercharger clutch, so had it replaced.
That said, my car is the R170 which had a known issue.
ladynoyes is offline  
#4 Old 07-30-2014
Registered Users
Join Date: Jul 2014
Location: St Louis, Missouri
Vehicle: 2003 SLK230
Other Toys: 1938 Austin Big Seven Ute
Posts: 8
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Similar Problem

Hi have a 2003 R170 with a similar noise I think. It's a rattling or perhaps a vibration at startup and when the engine is cold. It got REALLY bad on a recent trip and seemed to coincide with a slow leak/low level in the coolant. When I got home I changed the water pump. The noise improved SIGNIFICANTLY but it's still there.

It only happens when the car is cold. After warm up it seems to disappear. It also disappears at low RPM < about 1500 and disappears again at high acceleration/RPM > about 4500. The "sweet spot" to make the noise seems with a cold car between 1600 and about 3800 RPM.

Is it possible that there may be an air bubble in the coolant and the noise is caused by the pump running dry?? It irritates me that you can't fill directly into the radiator on this car and only into the expansion tank. . .

Anyone have any thoughts? Am I on the right track?
grahamnott is offline  
#5 Old 07-30-2014
Registered Users
Join Date: Apr 2012
Location: Houston, TX
Vehicle: Mercedes SLK 230 2003
Posts: 1,613
Chats: 0
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Thanks: 226
Thanked 379 Times in 265 Posts

Hmmm.. can it be the harmonic balancer or idler pulley?! Try to visually inspect pulleys and see if any of them are wobbling.
When I changed my coolant or when my coolant tank was leaking I used to top it up with some coolant and squeeze the big water coolant line on top several times with the cap still open, and you can hear "swoosh swoosh". This will force the air out. But if any bubbles are left it should come out via a venting whole so shouldn't be an issue with Mercedes.

Another thing you said you have a vibration... Is it like resonating and appears only at certain RPMs?! I'm saying it because it might be bad engine mounts. At least that's how my symptoms were. A resonating vibration sound that was hard to my ears at certain RPMs (think it was somewhere between 1500-2100). Replaced the mounts and was gone. Turned out one side gave up and I was able to squeeze it with my hand. It wasn't leaking though... So worthwhile to be checked.
JaysonM is offline  
Sponsored Links

  Lower Navigation
Go Back   Mercedes Benz SLK Forum > Mercedes Benz R170 SLK Class Cars > SLK R170 General Discussion


click, cold, engine, noise, start

Quick Reply
Upload your files to MEGAUPLOAD
Upload your images to ImageShack

Register Now

In order to be able to post messages on the Mercedes Benz SLK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


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

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
ID this 07 SLK55 Engine Noise Pls (VIDS ATTACHED) esqdg AMGs 34 04-23-2018 01:21 PM
Warm engine noise froome SLK R171 General Discussion 26 03-31-2015 12:13 PM
What that dreaded 'check engine' repair will cost you jbanks15 Off Topic 1 12-12-2012 09:32 PM
E 430 Amg dltslk Mercedes Benz Posers 4 04-02-2008 11:36 AM
Mercedes Benz DiesOtto Engine MarkR171 Off Topic 3 07-26-2007 08:05 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome

Clubs, Garage Plus vBulletin Plugins by Drive Thru Online, Inc.