Jun 15, 2015, 04:27 PM
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The warm start engine knock
Thread Starter
MBWorld Fanatic!
Joined: Apr 2007
Posts: 1,488
Likes: 439
From: San Diego, CA
2024 EQE 500
Got my car back. My invoice looks much like VFORCE09's. The "check valve" seems to be related to the tensioners themselves. I've only had the opportunity to test the fix one time so far and it sounds good to me. Will test a few more times to be sure. I can post my invoice if anyone wants it, and thanks to all for your input on this.
Newbie
Joined: Jul 2013
Posts: 4
Likes: 0
C350 4Matic
Merc diagnosed the issue on my car yesterday and parts ordered as per the TSB.
Unfortunately according to my service advisor up here in Canada, Germany has not sent them the tools required for the operation and they have been waiting for over a month.
Unfortunately according to my service advisor up here in Canada, Germany has not sent them the tools required for the operation and they have been waiting for over a month.
Member
Joined: Oct 2008
Posts: 232
Likes: 10
From: Ontario, Canada
2016 C450 AMG, 2012 C350 4Matic Sport
I am experiencing the same noise - almost always on warm starts. Sounds like someone shaking a can full of marbles - sometimes lasts for about 5 seconds.
I mentioned it to the service advisor at my last visit to the dealer (M-B Mississauga), she claimed it was normal, something to do with the design of the direct injection system. Claimed her B class did it all the time too. It sounded like BS to me and I pushed her on it but she wouldn't budge. I insisted she write it into the service log anyway, just in case of a problem down the road.
I keep trying to record it but sure enough, every time I start the sound recorder on my phone, the engine starts with out the sound. I guess I have to start doing it on every single warm start and maybe I''ll get something I can make them listen to at the dealership. Along with the info. in the above posts, this might make them do something.
I find it hard to believe that this won't cause any damage to the engine if it continues for years.
I mentioned it to the service advisor at my last visit to the dealer (M-B Mississauga), she claimed it was normal, something to do with the design of the direct injection system. Claimed her B class did it all the time too. It sounded like BS to me and I pushed her on it but she wouldn't budge. I insisted she write it into the service log anyway, just in case of a problem down the road.
I keep trying to record it but sure enough, every time I start the sound recorder on my phone, the engine starts with out the sound. I guess I have to start doing it on every single warm start and maybe I''ll get something I can make them listen to at the dealership. Along with the info. in the above posts, this might make them do something.
I find it hard to believe that this won't cause any damage to the engine if it continues for years.
Super Member
Joined: Jan 2013
Posts: 670
Likes: 7
From: Alberta
2014 E63 AMG S
Your SA is full of BS. Show her the attached fix document, it's what I had done to my M276 and it fixed the knocking noise.
Also this thread:
https://mbworld.org/forums/c-class-w...ml#post5952569
It's a 6-8 hour job.
Also this thread:
https://mbworld.org/forums/c-class-w...ml#post5952569
It's a 6-8 hour job.
Last edited by JaredP; Jul 14, 2014 at 01:17 PM.
Member
Joined: Oct 2008
Posts: 232
Likes: 10
From: Ontario, Canada
2016 C450 AMG, 2012 C350 4Matic Sport
Your SA is full of BS. Show her the attached fix document, it's what I had done to my M276 and it fixed the knocking noise.
Also this thread:
https://mbworld.org/forums/c-class-w...ml#post5952569
It's a 6-8 hour job.
Also this thread:
https://mbworld.org/forums/c-class-w...ml#post5952569
It's a 6-8 hour job.
Junior Member
Joined: Aug 2013
Posts: 73
Likes: 0
2010 C300 Sport
Engine noise...
Hello guys, I've been to the dealer a total of three times telling them the same issue (engine noise) at start up mostly after car has cooled down. I've been told by the stupid advisor that it is normal and that all C300 do have the same "knocking" sound at startups! My factory warranty expired in May 24th, 2014. Although I made sure that he write it everytime I went for service. I received a couple of calls from the MB Headquarters wanting feedback from me regarding the service visit. I told them all three times that I was NOT satisfied and that I did NOT belived that the "knocking" sound was normal either!!! What do you recommend? Should I call MB Headquarters and voice my concern? Should I go to my dealer with this "work order"?
Car runs fine with no missing or any problem other than that bothersome/embarrassing knocking f... g noise!!!
Thanks for your input guys!
Vickon
Car runs fine with no missing or any problem other than that bothersome/embarrassing knocking f... g noise!!!
Thanks for your input guys!
Vickon
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Super Member
Joined: Jan 2013
Posts: 670
Likes: 7
From: Alberta
2014 E63 AMG S
The document I posted is not regarding your engine, which is the 3.0L M272, not the 3.5L M276 in 2013+ C300s. I haven't heard of this issue in M272s but if it was documented and ignored, I would bet you still have a chance if it being serviced under warranty.
Newbie
Joined: Apr 2022
Posts: 2
Likes: 0
c250
did you figure out what the issue was? I have the exact same thing going on.
So I have had my 2013 C350 for about three weeks now. The other day my buddy was walking over to the car just as I started it, after it had been sitting for about an hour, and he pointed out the knock knock knock that lasts about 2-3 seconds.
I am familiar with DI motors as my Audi had one as well. That is not the sound in question. I started searching and it seems there are quite a few people reporting perceived "engine knock" on warm starts. Funny thing is I have no noises at a cold start, only warm.
My question is, how many of you have this same issue?
I am familiar with DI motors as my Audi had one as well. That is not the sound in question. I started searching and it seems there are quite a few people reporting perceived "engine knock" on warm starts. Funny thing is I have no noises at a cold start, only warm.
My question is, how many of you have this same issue?
