Loud idle

Tiny
BLACKNACOUSTIC
  • MEMBER
  • 2003 MERCEDES BENZ C320
  • 3.2L
  • V6
  • 4WD
  • AUTOMATIC
  • 239,616 MILES
Hey I bought a this car secondhand from someone and have been working on it. I have replaced the filters (air, oil, transmission) and put new ignition coils in as well. It's in limp mode currently and it idles very hard and makes a knocking like sound from the tappets cover or in the valve cover area making it sound like a diesel engine. Any suggestions or ideas?
Monday, November 18th, 2019 AT 2:51 PM

6 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,858 POSTS
Hi,

First, is it possible for you to record and upload the sound so I can hear it? Also, have you checked oil pressure and scanned for diagnostic trouble codes?

Let me know.
Joe
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Tuesday, November 19th, 2019 AT 7:42 PM
Tiny
BLACKNACOUSTIC
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  • 18 POSTS
Lol. So I will send a video tomorrow when I can get in front of the car. But i'm unable to scan because the scan tool turns on when plugged in but wont connect.
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Tuesday, November 19th, 2019 AT 7:47 PM
Tiny
BLACKNACOUSTIC
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Here is the video of the noise.
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Wednesday, November 20th, 2019 AT 12:11 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,858 POSTS
Hi,

I do hear a lifter noise. It can be caused by low oil pressure or a bad lifter. Is that what you are referring to?
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Wednesday, November 20th, 2019 AT 3:17 PM
Tiny
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Yes I believe so. I will have it checked out and keep you updated.
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Wednesday, November 20th, 2019 AT 3:24 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,858 POSTS
Hi,

The ticking is a lifter. Let me know what you find or if you have other questions.

Take care,
Joe
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Wednesday, November 20th, 2019 AT 4:17 PM

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