W209 Tapping Noise from Valvetrain
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Joined: Aug 2006
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W209 Tapping Noise from Valvetrain
Tried this on the technical forum, but perhaps it is better suited here...
Hi Folks:
W209 (clk 320). I bought the car a couple months ago and since have noticed this annoying...almost muted tapping noise coming from the engine. Faint at idle and increases upon accleration - most noticable at 2500-3000 RPM. It's driving me crazy. When the windows are open, I don't hear it as much. When I close the windows, I can hear it more. Here are the parameters:
Happens hot or cold
Air conditioning on or off
Oil changed to MObile 1 0W40 today, no change
Dealer replaced engine mounts
Dealer replaced Idler Pulley
Dealer says they took off the serpentine belt and noise still exists, appears to be from the valve-train and is within normal range.
Use 92 octone fuel from Chevron
It appears to be louder from inside the cabin
Any thoughts??
Hi Folks:
W209 (clk 320). I bought the car a couple months ago and since have noticed this annoying...almost muted tapping noise coming from the engine. Faint at idle and increases upon accleration - most noticable at 2500-3000 RPM. It's driving me crazy. When the windows are open, I don't hear it as much. When I close the windows, I can hear it more. Here are the parameters:
Happens hot or cold
Air conditioning on or off
Oil changed to MObile 1 0W40 today, no change
Dealer replaced engine mounts
Dealer replaced Idler Pulley
Dealer says they took off the serpentine belt and noise still exists, appears to be from the valve-train and is within normal range.
Use 92 octone fuel from Chevron
It appears to be louder from inside the cabin
Any thoughts??
Thread Starter
Newbie
Joined: Aug 2006
Posts: 18
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Probably not the purge valve
My understanding was that the purge valve on the left-hand side makes that constant knocking sound - like a diesel engine. I have that too 
but what I'm referring to is most probably from the valvetrain and the noise increases in volume and actually appears to increase in pitch when I accelerate. I can hear it faintly while at idle and it gets louder as I accelerate. Yes it's under warranty for under few years but the dealer recommends that we don't mess with it further as the noise is within normal range. (Some cars a quiter, and apparently some have the same noise?).
Thanks for the response, any others?
but what I'm referring to is most probably from the valvetrain and the noise increases in volume and actually appears to increase in pitch when I accelerate. I can hear it faintly while at idle and it gets louder as I accelerate. Yes it's under warranty for under few years but the dealer recommends that we don't mess with it further as the noise is within normal range. (Some cars a quiter, and apparently some have the same noise?).Thanks for the response, any others?
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,516
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From: Area 3
G63, AMG GT S
had similiar problem with my clk... knocking noise coming from the rear on the right... had it fixed under warranty. i dont hear the noise anymore. but they did have to special order the part from germany i think.
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Thread Starter
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Joined: Aug 2006
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I Figured It Out!!
I had the windshield replaced just before the noise started. I also heard some wind noise that wasn't around before and I could have sworn I smelt some mildew. So - yesterday I stuffed some towels (microfiber ) along the dash and the windsield and the noise was gone!! Apparently, the noise was a normal engine noise that was emminating into the interior because of a incorrectly installed windshield...!!
So I'll be getting that fixed today and giving the body shop hell.
Thanks for everyone's help.
) along the dash and the windsield and the noise was gone!! Apparently, the noise was a normal engine noise that was emminating into the interior because of a incorrectly installed windshield...!!So I'll be getting that fixed today and giving the body shop hell.
Thanks for everyone's help.
