SL/R230: Ratcheting noise at startup
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 337
Likes: 0
From: Montrose, CA
2007 SL550
Ratcheting noise at startup
Hi, folks, first thread....
I just bought my 2007 SL550 recently, but this didn't start happening until two days ago. When starting up the car in the morning, I hear a ratcheting noise -- kinda like fishing line being reeled out at high speed -- that goes on for about two seconds, then stops. From the driver seat, the noise sounds like it is coming from dead-center of the hood, near the top of the engine compartment. (It stops before I can hop out and check.)
Now, once it happened when I started the car, but once it happened before I even had the opportunity, so it may have been coincidence. (I have Keyless Go, so presumably the car was waking up before I started it.) This occurred when the outside temperature was around 47 F. It hasn't occurred when I've been at work, where I am in an underground garage that is pretty warm, so I am guessing this is a temperature-related thing, but haven't seen any similar-sounding posts here, so don't know if it is expected.
I'm guessing it is a stepper motor somewhere, but that is a total guess. Any help or direction would be appreciated.
I just bought my 2007 SL550 recently, but this didn't start happening until two days ago. When starting up the car in the morning, I hear a ratcheting noise -- kinda like fishing line being reeled out at high speed -- that goes on for about two seconds, then stops. From the driver seat, the noise sounds like it is coming from dead-center of the hood, near the top of the engine compartment. (It stops before I can hop out and check.)
Now, once it happened when I started the car, but once it happened before I even had the opportunity, so it may have been coincidence. (I have Keyless Go, so presumably the car was waking up before I started it.) This occurred when the outside temperature was around 47 F. It hasn't occurred when I've been at work, where I am in an underground garage that is pretty warm, so I am guessing this is a temperature-related thing, but haven't seen any similar-sounding posts here, so don't know if it is expected.
I'm guessing it is a stepper motor somewhere, but that is a total guess. Any help or direction would be appreciated.
Member
Joined: Feb 2009
Posts: 101
Likes: 0
non
That noise is probally coming from your starter. With other cars sometimes you hear a noise like that followed by the rumble of the engine.
Maybe poor electrical signals between your starter and sparkplugs. Iam guessing check your sparkplugs and sparkplugs wire?
Maybe poor electrical signals between your starter and sparkplugs. Iam guessing check your sparkplugs and sparkplugs wire?
Member
Joined: Sep 2006
Posts: 216
Likes: 27
From: Clear Lake Shores, Texas
2026 AMG CLE 53, 2026 BMW X5, 1972 Corvette
Don't know if it is the same thing, but my SL55 make a similar noise. On one occasion it never stopped until I disconnected the secondary battery which turned out be a relay issue. In my case the noise is coming from the secondary air injection pump, and now that I know what it is I can hear it when I first start the car in the morning. Cuts off after a few seconds normally. Something to do with the emission system.
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 337
Likes: 0
From: Montrose, CA
2007 SL550
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 337
Likes: 0
From: Montrose, CA
2007 SL550
Can you hear it consistently, as in every morning? Or only in certain temperature ranges?
Trending Topics
Member
Joined: Mar 2004
Posts: 170
Likes: 0
From: San Francisco Bay Area
2003 SL500
Is this on startup, or before? Wondering if you are hearing the SBC pre-load. As I understand it, when you open the door (I don't have keyless go), the system pumps up the pressure in the SBC system to be ready to go. I'd describe the sound as a bit like a ratchet, or a short burst of garage door (but softer).
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 337
Likes: 0
From: Montrose, CA
2007 SL550
Is this on startup, or before? Wondering if you are hearing the SBC pre-load. As I understand it, when you open the door (I don't have keyless go), the system pumps up the pressure in the SBC system to be ready to go. I'd describe the sound as a bit like a ratchet, or a short burst of garage door (but softer).
http://www.benzworld.org/forums/w211...ml#post3207374
This is almost identical to what I am hearing, albeit for a shorter period. Thanks for the tip!
Member
Joined: Dec 2008
Posts: 244
Likes: 1
From: Louisiana
2005 SL500
Bingo! ToonArmy wins. When I googled "SBC pump" I found a link at benzworld where somebody posted a clip of what it sounds like on an E-Class:
http://www.benzworld.org/forums/w211...ml#post3207374
This is almost identical to what I am hearing, albeit for a shorter period. Thanks for the tip!
http://www.benzworld.org/forums/w211...ml#post3207374
This is almost identical to what I am hearing, albeit for a shorter period. Thanks for the tip!
Milandis, have you ever tried to start a car with a bad or broken starter?
Rook
Thread Starter
Senior Member
Joined: Jan 2009
Posts: 337
Likes: 0
From: Montrose, CA
2007 SL550
