Piston-slap-like noise when accelerating

White340 · 05-19-2019, 09:14 PM

Hi,

I just started hearing what sounds like a piston slap sound on my 2018 M3 ZCP with ~2.5k miles on it. Watch the video and see if you can hear the noise between 2-2.5k RPMs when accelerating. Is this normal?

NPuter · 05-20-2019, 08:22 AM

Mine makes the exact same noise in the exact same range! It's pretty metallic sounding with the windows down right?

I've been meaning to try to capture it in a video/post here about it. Will make a point to now to confirm.

I mentioned it to my tech at the one year service. He said he took it for a drive, and it sounded normal. Definitely never felt right to me.

White340 · 05-20-2019, 09:09 AM

This is the noise with the windows up. It just started making this noise yesterday. I haven't heard it in the last 2.5k miles.

///M/// · 05-20-2019, 09:17 AM

Do you mean like a tiny metal clank?

Jim B · 05-20-2019, 10:03 AM

Quote:

Originally Posted by BMWModel3

Mine plays the tiniest violin

Just don't fiddle with it!!

minn19 · 05-20-2019, 05:24 PM

No that is not normal. Take it in.

Poiseuille · 05-20-2019, 07:28 PM

Quote:

Originally Posted by Jim B

Quote:

Originally Posted by BMWModel3

Mine plays the tiniest violin

Just don't fiddle with it!!

........thud

White340 · 05-20-2019, 09:43 PM

Quote:

Originally Posted by minn19

No that is not normal. Take it in.

Damnit. I haven't even redlined this car yet. Highest I've been is like 5k rpm and only a couple times. Wonder what this could be.

TrevorM3 · 05-20-2019, 10:06 PM

sounds like a little rattle.

i hate small little noises becuase it's somewhat "subjective"

you take it to the dealer and tech may say normal, take it to another one and he may say you need a new motor lol

minn19 · 05-21-2019, 10:18 AM

Quote:

Originally Posted by White340

Damnit. I haven't even redlined this car yet. Highest I've been is like 5k rpm and only a couple times. Wonder what this could be.

Sorry, I've had three different M3/4s including my current one and I've never heard anything like that. Hopefully it is something easy as others have suggested. But, I'd still get checked out at a dealer if anything to get it documented for possible future warranty issues. It sucks, but drive/commute in their loaner around for a few days and save the miles on your car.

08mojo · 05-22-2019, 09:32 AM

I can definitely hear the subtle knocking noise in the video. My car does definitely not make that noise. I'd take it in and at least have it documented if nothing else.

White340 · 06-09-2019, 08:43 PM

So it looks like it could be the low pressure AC hose that is making the noise. Apparently this is a common issue on the 335.

Someone also had this noise on their M3 and it is documented in this thread : https://f80.bimmerpost.com/forums/sh....php?t=1439954

I'm surprised no one else hears this sound. My M3 was built in August 2018 so if I have it I don't know how anyone else doesn't. I can easily replicate it by driving in eco mode with the AC on and accelerating in 2nd/3rd/4th gear between 2-3k RPMs.

I'm thinking of just buying the weight that resolves this issue for 10 dollars and doing it myself rather than taking it into the dealer which is a whole ordeal.

drjoe66 · 06-12-2019, 12:47 PM

I am having exactly the same noise on my 10/2017 M3. Same rpm range. Took it to the dealer, they cannot reproduce.....of course.

TurboM · 06-13-2019, 01:20 AM

Almost impossible to tell based on the video but a small exhaust leak can resemble a similar type of noise. Highly doubt its "piston slap", which would be a highly improbable engine assembly defect.

White340 · 06-13-2019, 07:52 AM

Quote:

Originally Posted by TurboM

Almost impossible to tell based on the video but a small exhaust leak can resemble a similar type of noise. Highly doubt its "piston slap", which would be a highly improbable engine assembly defect.

I put a link above of someone who has the same noise. In his case the dealer put a weight on the low pressure AC hose and it solved the issue. This was also a common problem on the N55 motor but that issue seemed to be resolved through a design update. I would have thought that the same design update would make its way through to a 2018 built M3 but maybe not.

Kief · 06-13-2019, 07:59 AM

My M3CS has it...likely the AC line

White340 · 06-13-2019, 08:15 AM

Anyone know which like is the low pressure AC line or have a pic of the weight attached to that line? The location on the N55 is different.

Kief · 06-13-2019, 08:53 AM

Quote:

Originally Posted by White340

Anyone know which like is the low pressure AC line or have a pic of the weight attached to that line? The location on the N55 is different.

The Thread that was referenced above has since closed, but I took a pic. Apparently, it is the low pressure line.

Better yet, BlatantMaple854 you have a copy of your invoice?

mando3 · 06-13-2019, 09:37 PM

that noise drove me nuts in my 435i, three years putting up with it and I figured it out like a month before I traded the car in, BMW has a service bulletin for it SIB 64-01-14, I don't know if it applies to f8x cars as well

BlatantMaple854 · 06-14-2019, 09:35 PM

Quote:

Originally Posted by kief

the thread that was referenced above has since closed, but i took a pic. Apparently, it is the low pressure line.

Better yet, you have a copy of your invoice?

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OP's video is the exact same issue I had. Trust me, this will solve the problem.

White340 · 06-15-2019, 10:56 AM

Quote:

Originally Posted by BlatantMaple854

Attachment 2077406

Attachment 2077407

OP's video is the exact same issue I had. Trust me, this will solve the problem.

Do you have a picture of the actual weight installed in your car so we can see the location? Thanks

NPuter · 06-17-2019, 11:18 AM

Quote:

Originally Posted by White340

So it looks like it could be the low pressure AC hose that is making the noise. Apparently this is a common issue on the 335.

Someone also had this noise on their M3 and it is documented in this thread : https://f80.bimmerpost.com/forums/sh....php?t=1439954

I'm surprised no one else hears this sound. My M3 was built in August 2018 so if I have it I don't know how anyone else doesn't. I can easily replicate it by driving in eco mode with the AC on and accelerating in 2nd/3rd/4th gear between 2-3k RPMs.

I'm thinking of just buying the weight that resolves this issue for 10 dollars and doing it myself rather than taking it into the dealer which is a whole ordeal.

Thanks for the info!

My car was built in September 2018, and I believe I have the exact (or very similar) noise. The only thing is I believe mine makes the noise whether or not the AC is on. I've been meaning to grab a video to compare (will do so this afternoon).

Do you know if this is an easy DIY fix? Closest dealer is 100 miles away from me.

05-19-2019, 09:14 PM	#1
White340 Lieutenant Colonel 1392 Rep 1,986 Posts Drives: 2018 M3 Comp / 2022 X5 45e Join Date: Dec 2015 Location: NYC iTrader: (3)	Piston-slap-like noise when accelerating Hi, I just started hearing what sounds like a piston slap sound on my 2018 M3 ZCP with ~2.5k miles on it. Watch the video and see if you can hear the noise between 2-2.5k RPMs when accelerating. Is this normal? __________________ 2022 X5 45e : AW/Tartufo 2018 M3 Competition : AW/SO 2016 340i xDrive : AW/CR (sold)
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05-20-2019, 08:22 AM	#2
NPuter Private First Class 158 Rep 139 Posts Drives: F80 Join Date: Oct 2013 Location: Miami, FL \| Boone, NC iTrader: (0)	Mine makes the exact same noise in the exact same range! It's pretty metallic sounding with the windows down right? I've been meaning to try to capture it in a video/post here about it. Will make a point to now to confirm. I mentioned it to my tech at the one year service. He said he took it for a drive, and it sounded normal. Definitely never felt right to me. __________________ 2018 F80 M3 • Silverstone/Silverstone • DCT/ZCP/Exec/Assist/Blind Spot 2016 B8 S5
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05-20-2019, 09:09 AM	#3
White340 Lieutenant Colonel 1392 Rep 1,986 Posts Drives: 2018 M3 Comp / 2022 X5 45e Join Date: Dec 2015 Location: NYC iTrader: (3)	This is the noise with the windows up. It just started making this noise yesterday. I haven't heard it in the last 2.5k miles. __________________ 2022 X5 45e : AW/Tartufo 2018 M3 Competition : AW/SO 2016 340i xDrive : AW/CR (sold)
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05-20-2019, 09:17 AM	#4
///M/// Brigadier General 1862 Rep 3,661 Posts Drives: 2016 Manual AW F80 Join Date: Jul 2009 Location: Philly iTrader: (6)	Do you mean like a tiny metal clank? __________________ ========================= 2016 F80 M3 AW/SO (Manual) - Picked up at the Welt 08/28/15 My Amazing European Delivery Story
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05-20-2019, 05:24 PM	#6
minn19 Lieutenant General 14024 Rep 10,076 Posts Drives: 24 Z06, 23 CT4VBW, 22 PFinder Join Date: Jul 2013 Location: Minnesota iTrader: (0)	No that is not normal. Take it in.
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05-20-2019, 10:06 PM	#9
TrevorM3 Banned 3322 Rep 8,083 Posts Drives: 6.3 AMG Join Date: Apr 2013 Location: Florida iTrader: (0)	sounds like a little rattle. i hate small little noises becuase it's somewhat "subjective" you take it to the dealer and tech may say normal, take it to another one and he may say you need a new motor lol
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05-22-2019, 09:32 AM	#11
08mojo Private 77 Rep 86 Posts Drives: 2018 M3 Join Date: Mar 2018 Location: Atlanta iTrader: (0)	I can definitely hear the subtle knocking noise in the video. My car does definitely not make that noise. I'd take it in and at least have it documented if nothing else.
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06-09-2019, 08:43 PM	#12
White340 Lieutenant Colonel 1392 Rep 1,986 Posts Drives: 2018 M3 Comp / 2022 X5 45e Join Date: Dec 2015 Location: NYC iTrader: (3)	So it looks like it could be the low pressure AC hose that is making the noise. Apparently this is a common issue on the 335. Someone also had this noise on their M3 and it is documented in this thread : https://f80.bimmerpost.com/forums/sh....php?t=1439954 I'm surprised no one else hears this sound. My M3 was built in August 2018 so if I have it I don't know how anyone else doesn't. I can easily replicate it by driving in eco mode with the AC on and accelerating in 2nd/3rd/4th gear between 2-3k RPMs. I'm thinking of just buying the weight that resolves this issue for 10 dollars and doing it myself rather than taking it into the dealer which is a whole ordeal. __________________ 2022 X5 45e : AW/Tartufo 2018 M3 Competition : AW/SO 2016 340i xDrive : AW/CR (sold)
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06-12-2019, 12:47 PM	#13
drjoe66 Captain 329 Rep 757 Posts Drives: 2021 M5 & 2019 X3 Join Date: Nov 2008 Location: Carolinas iTrader: (0)	I am having exactly the same noise on my 10/2017 M3. Same rpm range. Took it to the dealer, they cannot reproduce.....of course. __________________ 2019 X3 2021 M5 Comp On order: 2022 X3M40i
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06-13-2019, 01:20 AM	#14
TurboM Captain 252 Rep 674 Posts Drives: 2018 F82 M4 ZCP Join Date: Nov 2013 Location: Atlanta iTrader: (1)	Almost impossible to tell based on the video but a small exhaust leak can resemble a similar type of noise. Highly doubt its "piston slap", which would be a highly improbable engine assembly defect.
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06-13-2019, 07:59 AM	#16
Kief Major General 4433 Rep 5,729 Posts Drives: '24 iX50; '23 i4 M50 Join Date: Dec 2009 Location: Vereinigte Staaten von Amerika iTrader: (26)	My M3CS has it...likely the AC line __________________ __________________ '24-I20 iX 50; '23-G26 i4 M50; '22-G82 M4Cx;20-G05 M50i; '20-F82 M4CS; '18-F80 M3CS; '18-F80 M3CS; '18-F85 X5M; '18-G01 X3M40i; '18-F80 M3ZCP; '17-F80 M3ZCP; '15-F15 X5; '15-F82 M4; '12-E92 335is; '11-E70 X5d; '11-E89 Z435is;'09-E89 Z435i; '08-E92 335i; '06-E90 330i; '05-E83 X3; '04-E83 X3; '03-E46 325Ci* *retired
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06-13-2019, 08:15 AM	#17
White340 Lieutenant Colonel 1392 Rep 1,986 Posts Drives: 2018 M3 Comp / 2022 X5 45e Join Date: Dec 2015 Location: NYC iTrader: (3)	Anyone know which like is the low pressure AC line or have a pic of the weight attached to that line? The location on the N55 is different. __________________ 2022 X5 45e : AW/Tartufo 2018 M3 Competition : AW/SO 2016 340i xDrive : AW/CR (sold)
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06-13-2019, 09:37 PM	#19
mando3 Registered 2 Rep 4 Posts Drives: 2006 325i Join Date: Jul 2012 Location: SA iTrader: (1)	that noise drove me nuts in my 435i, three years putting up with it and I figured it out like a month before I traded the car in, BMW has a service bulletin for it SIB 64-01-14, I don't know if it applies to f8x cars as well
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