Slight Grinding Noise - Low Revs & When Cold
08-17-2016, 07:35 AM
#1
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Thread Starter
Slight Grinding Noise - Low Revs & When Cold
My car sits a while between uses, but the last two times I've driven it I now notice a slight grinding noise (I think, could be a dull rattle) when at low revs and from the front half of the car, say under 2000rpm and only when I press on the throttle a little. That sounds weird, but if I feather the throttle it doesn't happen, and if I nail it it doesn't, only ever on part throttle which seems to produce the right load/vibration to cause it. This also doesn't happen while free-revving in Neutral or Park, it is purely cause by load it seems.
The car is a 2013 Coupe with MCT.
I should add here that it is only when the car is cold that this happens and when driven for a while it is totally gone. I figured the first time that it could be something brake related, as I cleaned it and then put it away in the garage where corrosion on the disc may have occurred but, as it is still there this can't be the case and the noise is certainly not rotational since I've had more time to listen. Still, as a matter of precaution I took the front wheels off and checked the brakes over, then jacked it up a little more to checked exhaust heat shields and the like...but everything is good.
Has anyone had anything like this before?
I found this thread online which sounds similar, but is this stuff related to the M156 also? http://www.benzworld.org/forums/w202...ning-part.html
I make sure to maintain my car and keep things lubed, but again for good measure I have given a quick squirt of WD40 to the pulley's visible from the top of the engine.
I plan to get it in the air this weekend, take off the under-tray and look harder but everything looks good. It was in for it's annual service 4wks ago and it came back with a clean bill of health and an "immaculate" comment from the MB tech and service advisor. These are usually the guys desperate to drum up more business, so it would be odd for them to let the car pass through with any issues.
In terms of performance, or any negative effects elsewhere, there's nothing. The car runs like a dreams, goes like a train and does what it has always done. I'm stumped.
The car is a 2013 Coupe with MCT.
I should add here that it is only when the car is cold that this happens and when driven for a while it is totally gone. I figured the first time that it could be something brake related, as I cleaned it and then put it away in the garage where corrosion on the disc may have occurred but, as it is still there this can't be the case and the noise is certainly not rotational since I've had more time to listen. Still, as a matter of precaution I took the front wheels off and checked the brakes over, then jacked it up a little more to checked exhaust heat shields and the like...but everything is good.
Has anyone had anything like this before?
I found this thread online which sounds similar, but is this stuff related to the M156 also? http://www.benzworld.org/forums/w202...ning-part.html
I make sure to maintain my car and keep things lubed, but again for good measure I have given a quick squirt of WD40 to the pulley's visible from the top of the engine.
I plan to get it in the air this weekend, take off the under-tray and look harder but everything looks good. It was in for it's annual service 4wks ago and it came back with a clean bill of health and an "immaculate" comment from the MB tech and service advisor. These are usually the guys desperate to drum up more business, so it would be odd for them to let the car pass through with any issues.
In terms of performance, or any negative effects elsewhere, there's nothing. The car runs like a dreams, goes like a train and does what it has always done. I'm stumped.
Last edited by Cozy; 08-17-2016 at 07:38 AM.
08-18-2016, 02:53 AM
#2
Senior Member
Thread Starter
Well, I took it for a decent run last night and it's more a rattle than a grind, and specifically at around 1200-1300rpm when the engine is loading. Past 1300rpm, the noise is gone so would seem to be vibration based.
To be honest I doubt anyone has had this issue before, and probably has come about from me not using the car enough. I anticipate heat shield at rear of engine so it looks like a fun weekend moving and tightening the fixing of those, while I'm under it doing alignment anyway.
To be honest I doubt anyone has had this issue before, and probably has come about from me not using the car enough. I anticipate heat shield at rear of engine so it looks like a fun weekend moving and tightening the fixing of those, while I'm under it doing alignment anyway.
Last edited by Cozy; 08-18-2016 at 03:28 AM.
08-21-2016, 09:18 AM
#4
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2008 MB C350 4MATIC/2011 CL63 AMG/2014 C63 Coupe 507
Mine does the same, I have MHP / American Racing headers. Very concerning noise at times from seems of it but no damage from what I know. I will be following this thread closely.
08-22-2016, 04:39 PM
#5
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2007 Mercedes E63 AMG
when you install long tubes, you'll get a more noisy engine. it'll sound like a chain moving while at low rpm for some. aftermarket headers generally have thinner wall tubing which translate to more noise from the engine.
with my E63 i believe the header comes into contact with the steering column at times. at full lock in one direction i do think i feel the header tapping or rubbing on the steering shaft. while making u-turns.
with my E63 i believe the header comes into contact with the steering column at times. at full lock in one direction i do think i feel the header tapping or rubbing on the steering shaft. while making u-turns.
08-22-2016, 06:31 PM
#6
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
There is a chassis brace just in front of the resonators. This is a common place for LTHs to tap. On my MBH install I left this brace off as there was no way it would fit without touching the exhaust at times. Worth having a look to see if the exhaust is hitting it.
11-18-2016, 12:27 PM
#7
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Thread Starter
Well, I thought I'd conclude this now I've had a chance to be home for one, and secondly get it up on a lift. by the way, my car is stock other than ECV5.
I put the car up and started tapping the exhaust tubes to see if I could get a heat shield to resonate. Left one, no noise at all and totally solid. Right one however has a rattle and it gets louder the closer I tap to the engine. I get to the transmission and I find it, a heat shield laying on the exhaust totally unattached. My car was in at MB only a couple weeks before for a trans service, so this is down to them not refitting it.
It was a 2min job to sort, but I called my dealer and voiced my disappointment.
I put the car up and started tapping the exhaust tubes to see if I could get a heat shield to resonate. Left one, no noise at all and totally solid. Right one however has a rattle and it gets louder the closer I tap to the engine. I get to the transmission and I find it, a heat shield laying on the exhaust totally unattached. My car was in at MB only a couple weeks before for a trans service, so this is down to them not refitting it.
It was a 2min job to sort, but I called my dealer and voiced my disappointment.
