Loud vibration on cold start

moonshine89 · 10-05-2018, 01:59 AM

Quote:

Originally Posted by -cj-

My cold starts are a bit embarrassing... can't believe how loud it is.

I stepped out of the car one morning and watched my exhaust to see if it was hitting the diffuser like someone posted in this thread. It wasn't, but I was surprised by how much movement there was on the tail pipes! The whole exhaust was very visibly vibrating at an insane frequency. I'll try to take a video...

I agree!! I leave super early in the am and I'm in a cul de sac. So my car is ridiculously loud. And the vibrations make me want to scream. I hate them so much. They seem to be getting worse.

Unfortunately I don't have time to get it in the shop. Is there a way to adjust the exhaust positioning? Can I adjust the hangers or something?

Howard_R · 10-05-2018, 03:48 AM

I couldn't stand the ridiculously loud cold start so as part of a flash tune, I had them turn it off - no more stupid loud cold start

. I still have the 1-2 second roar on start up, and then it's straight into idle. The cold start roar that last a minute or two is part of the heating up the cats for emissions purposes I think. If you have the MPE, it's stupid loud.

moonshine89 · 10-05-2018, 09:08 AM

Quote:

Originally Posted by Howard_R

I couldn't stand the ridiculously loud cold start so as part of a flash tune, I had them turn it off - no more stupid loud cold start

. I still have the 1-2 second roar on start up, and then it's straight into idle. The cold start roar that last a minute or two is part of the heating up the cats for emissions purposes I think. If you have the MPE, it's stupid loud.

It's terribly loud. For me it seems like an exhaust alignment issue. This morning the moment I started the car I ran back and pulled on the exhaust (away from the diffuser) and had no terrible vibrations. So I'm trying to get someone to fix my exhaust (i.e. BMW).

Does anyone have any thoughts on re aligning the exhaust? Are the hangers adjustable?

Can the Admins move this to the exhaust section? My bad!

Andrae26 · 10-05-2018, 09:35 AM

Quote:

Originally Posted by moonshine89

Quote:

Originally Posted by Howard_R

I couldn't stand the ridiculously loud cold start so as part of a flash tune, I had them turn it off - no more stupid loud cold start

. I still have the 1-2 second roar on start up, and then it's straight into idle. The cold start roar that last a minute or two is part of the heating up the cats for emissions purposes I think. If you have the MPE, it's stupid loud.

It's terribly loud. For me it seems like an exhaust alignment issue. This morning the moment I started the car I ran back and pulled on the exhaust (away from the diffuser) and had no terrible vibrations. So I'm trying to get someone to fix my exhaust (i.e. BMW).

Does anyone have any thoughts on re aligning the exhaust? Are the hangers adjustable?

Can the Admins move this to the exhaust section? My bad!

I had the same issue on my M4 when I had it installed by a shop. Took it to the dealership and the SA said the exhaust was not aligned properly. It was moving around a lot. Fast forward 2 months later I transferred the exhaust from my M4 to my M3 and had it installed by my friend because the dealership wanted too much for the installation. Not rattled or vibrations since then, I would recommend reinstalling the exhaust.

moonshine89 · 10-05-2018, 09:43 AM

The "x" on the right side of the exhuast tip is not equal on my mine. How do I adjust this? I'm going to try to do it myself.

moonshine89 · 10-10-2018, 04:22 AM

In case anyone cares...

BMW agreed the alignment of the exhaust was off and causing intermittent vibrations against the m diffuser. The thread below shows my issue.

https://f80.bimmerpost.com/forums/sh....php?t=1465147

The shop foreman also told me there's an additional odd sound. So he goes exploring and sees an area concerning for a hairline crack. Gets approval from bmw to take care of the entire think almost preemptively. Get a completely new mpe! Unfortunately, I was in a rush to get back to work after picking up the car and didn't notice the tips were wicked far out.

So I ended up gently removing the special screws, cleaned them up, and added loctite 271 after adjusting them to my liking. I was wondering what the standard position of the exhaust tips were. Saw a lot of variation in different pictures but ended up with them tucked just under the diffuser.

There's one pic in there comparing the different positions. The left side was my adjustment and the right was the recent install.

damageprone · 10-10-2018, 09:59 AM

Quote:

Originally Posted by moonshine89

Gets approval from bmw to take care of the entire think almost preemptively. Get a completely new mpe!

So you got a new MPE? If so, hopefully you get the new and improved one! Hopefully it takes care of the rattle for you. But the loud cold start will not go away unfortunately. That's built into the software.

EricSMG · 10-10-2018, 11:49 AM

My car produces a metallic rattle (not a vibration) immediately after startup, every time, lasts about one second. Seems like it's coming from the front of the car.

Dealer said "normal". I'm not worried about it but yes, it is somewhat funny for a car that costs what this car does.

CigarPundit · 10-10-2018, 12:02 PM

Quote:

Originally Posted by EricSMG

My car produces a metallic rattle (not a vibration) immediately after startup, every time, lasts about one second. Seems like it's coming from the front of the car.

Dealer said "normal". I'm not worried about it but yes, it is somewhat funny for a car that costs what this car does.

That’s what I have. I’ve noticed it’s not just on cold starts and that’s what I’m told is coming from the waste gates. Not a huge deal I guess but I hate it and it just shouldn’t happen on a car at this price point. Then again, it shouldn’t sound like a lawn mower either. Oh, and those farts. These are shortcomings of the F8x IMO.

moonshine89 · 10-10-2018, 03:24 PM

Quote:

Originally Posted by damageprone

Quote:

Originally Posted by moonshine89

Gets approval from bmw to take care of the entire think almost preemptively. Get a completely new mpe!

So you got a new MPE? If so, hopefully you get the new and improved one! Hopefully it takes care of the rattle for you. But the loud cold start will not go away unfortunately. That's built into the software.

Yep. I checked as well. Used to have the 03 version. Now have the 04 version. I haven't done an in depth eval but the most obvious difference was the extra support flange holding the edge of the exhaust pipes to the box. Maybe this decreases the risk of cracking?

damageprone · 10-10-2018, 04:14 PM

Quote:

Originally Posted by moonshine89

Yep. I checked as well. Used to have the 03 version. Now have the 04 version. I haven't done an in depth eval but the most obvious difference was the extra support flange holding the edge of the exhaust pipes to the box. Maybe this decreases the risk of cracking?

Strange, you already had the improved one. 03 should have already had the improved flanges. Interesting.

moonshine89 · 10-30-2018, 11:08 AM

Here's a pic of the new version with the flange. It's night and day. When I used to start the car on the previous exhaust the tips would vibrate intensely, but now no movement or vibration with the flanged version!

TedRules · 10-31-2018, 07:26 PM

Often times this will be one, or both, of the exhaust valves. Replacing them renders no more rattling vibrations from the rear part of the exhaust. Warranty covers this in many cases. I have seen this as being the culprit 3 different times on 3 different vehicles. Each time, the rattle was eliminated.

10-05-2018, 03:48 AM	#24
Howard_R Private 84 Rep 81 Posts Drives: 2017 Sakhir Orange M4 Join Date: Jan 2013 Location: Seattle iTrader: (1)	I couldn't stand the ridiculously loud cold start so as part of a flash tune, I had them turn it off - no more stupid loud cold start . I still have the 1-2 second roar on start up, and then it's straight into idle. The cold start roar that last a minute or two is part of the heating up the cats for emissions purposes I think. If you have the MPE, it's stupid loud.
	Appreciate 0 Quote

10-05-2018, 09:43 AM	#27
moonshine89 Second Lieutenant 152 Rep 269 Posts Drives: 18 M3 ZCP Join Date: Feb 2018 Location: United States iTrader: (1)	The "x" on the right side of the exhuast tip is not equal on my mine. How do I adjust this? I'm going to try to do it myself. Attached Images
	Appreciate 0 Quote

10-10-2018, 04:22 AM	#28
moonshine89 Second Lieutenant 152 Rep 269 Posts Drives: 18 M3 ZCP Join Date: Feb 2018 Location: United States iTrader: (1)	In case anyone cares... BMW agreed the alignment of the exhaust was off and causing intermittent vibrations against the m diffuser. The thread below shows my issue. https://f80.bimmerpost.com/forums/sh....php?t=1465147 The shop foreman also told me there's an additional odd sound. So he goes exploring and sees an area concerning for a hairline crack. Gets approval from bmw to take care of the entire think almost preemptively. Get a completely new mpe! Unfortunately, I was in a rush to get back to work after picking up the car and didn't notice the tips were wicked far out. So I ended up gently removing the special screws, cleaned them up, and added loctite 271 after adjusting them to my liking. I was wondering what the standard position of the exhaust tips were. Saw a lot of variation in different pictures but ended up with them tucked just under the diffuser. There's one pic in there comparing the different positions. The left side was my adjustment and the right was the recent install. Attached Images
	Appreciate 0 Quote

10-10-2018, 11:49 AM	#30
EricSMG Captain 576 Rep 829 Posts Drives: E46 M3 Join Date: Mar 2016 Location: San Diego iTrader: (0)	My car produces a metallic rattle (not a vibration) immediately after startup, every time, lasts about one second. Seems like it's coming from the front of the car. Dealer said "normal". I'm not worried about it but yes, it is somewhat funny for a car that costs what this car does.
	Appreciate 0 Quote

10-30-2018, 11:08 AM	#34
moonshine89 Second Lieutenant 152 Rep 269 Posts Drives: 18 M3 ZCP Join Date: Feb 2018 Location: United States iTrader: (1)	Here's a pic of the new version with the flange. It's night and day. When I used to start the car on the previous exhaust the tips would vibrate intensely, but now no movement or vibration with the flanged version! Attached Images
	Appreciate 1 damageprone580.50 Quote

10-31-2018, 07:26 PM	#35
TedRules Enlisted Member 26 Rep 34 Posts Drives: BMW's and Truck Join Date: Aug 2011 Location: Kansas iTrader: (1)	Often times this will be one, or both, of the exhaust valves. Replacing them renders no more rattling vibrations from the rear part of the exhaust. Warranty covers this in many cases. I have seen this as being the culprit 3 different times on 3 different vehicles. Each time, the rattle was eliminated.
	Appreciate 1 damageprone580.50 Quote