Exhaust Thuds after Resonator Delete?

NYC_340i · 06-11-2017, 11:24 PM

Hello everyone.

I've had both the resonators removed on my '16 340i xDrive a month ago and I was really in love with such a simple change. But that only lasted about 2 weeks and ever since I've been hearing some thuds coming from underneath the car every time I hit a moderate to big size pothole. It sounds like the exhaust is hitting the underside of the car and it happens more often if the right 2 wheels hit the pothole over the left 2. Living in NYC where the roads are not that great doesn't help either. I checked underneath the car and cannot find any indication of something hitting the exhaust. I initially thought it would be the brace in the center of the car since the clearance is less compared to stock with the new stainless steel pipe but there seems to be no damage there. If I grab the exhaust tip and shake it hard I can hear it start to make the same sound.

Oh and I checked both hangers on the mufflers as well as the bolt in the front and the connection to the downpipe and they all seem to be fine.

Anyone have any idea what it can be? I'll try to get it on video if that will help. Thanks in advance.

PeterA90 · 06-12-2017, 08:34 AM

It's not tightened properly

Climb Mode · 06-12-2017, 03:32 PM

Quote:

Originally Posted by PeterA90

It's not tightened properly

I think they are supposed to re-do this process after getting the exhaust hot. Maybe the installer neglected to do so.

NYC_340i · 06-12-2017, 04:38 PM

Quote:

Originally Posted by PeterA90

It's not tightened properly

Quote:

Originally Posted by Climb Mode

I think they are supposed to re-do this process after getting the exhaust hot. Maybe the installer neglected to do so.

I will try tightening all the bolts again. They just installed the new pipe and gave me back the car so I guess that is what is happening.

Thanks guys!

SingleturboVert · 06-12-2017, 06:28 PM

Report back

NYC_340i · 06-12-2017, 07:35 PM

Quote:

Originally Posted by SingleturboVert

Report back

Not sure if it's placebo but tightening the front exhaust support near the downpipe may have reduced it a little. Over some of the bigger bumps I still hear the same thuds coming from the mid to rear section. I tried my best to crawl under and check both clamps near the muffler and they seem to be inserted and bolted on properly. Only thing I didn't try tightening is the support brace in the center as I couldn't find what type of bolt that was and it was getting dark.

I just tightened the front support a little with a breaker bar. Didn't know if I should go tighter. It was pretty loose but idk if that's the bolt or just the breaker bar doing its job. Is there a torque spec I should get that to with a torque wrench?

perryo91 · 06-12-2017, 08:02 PM

Im looking at getting my resonator / resonators deleted.

What should I mention to the exhaust shop to make sure they do this? Would I need to come back for a "Follow up appointment" to tighten it when its warm?

Anyone got some tips? Thank you!

Dinan_Rated · 06-12-2017, 11:25 PM

Quote:

Originally Posted by perryo91

Im looking at getting my resonator / resonators deleted.

What should I mention to the exhaust shop to make sure they do this? Would I need to come back for a "Follow up appointment" to tighten it when its warm?

Anyone got some tips? Thank you!

Have done this many times and currently on my f30. Never had to go back or have anything loosen on me. This sounds like another issue to me.

riskmaker76 · 06-13-2017, 08:47 AM

Its a simple misalignment of your exhaust... go back and have them adjust it

The only way to test it is get it on a lift and push up on the entire exhaust and see if it hits... Pushing on the mufflers itself is useless... To do it right they would have had to taken down / unbolted everything..

Thats why I just recommend getting the dinan mid pipe... an idiot can install that.. the other way your at the mercy of whoever is doing the cutting and welding.

elicausi · 06-13-2017, 10:49 AM

Quote:

Originally Posted by riskmaker76

Its a simple misalignment of your exhaust... go back and have them adjust it

The only way to test it is get it on a lift and push up on the entire exhaust and see if it hits... Pushing on the mufflers itself is useless... To do it right they would have had to taken down / unbolted everything..

Thats why I just recommend getting the dinan mid pipe... an idiot can install that.. the other way your at the mercy of whoever is doing the cutting and welding.

Can Dianan mid pipe be installed without a lift by a DIYer? I'm not quite an idiot, but not too far off when it comes to mechanics.

Climb Mode · 06-13-2017, 11:15 AM

Quote:

Originally Posted by elicausi

Can Dianan mid pipe be installed without a lift by a DIYer? I'm not quite an idiot, but not too far off when it comes to mechanics.

99% sure 0% chance.

riskmaker76 · 06-13-2017, 02:22 PM

Possible but tough without a lift... You would want to jack the car up and put on stands at least... Exhaust I say no issues... but mid pipe - real pain without it in the air. I did cat back exhaust many years ago on stands... It was tough... then had alignment issues. In the end had to take it to a shop with a lift to position everything and retighten.

Quote:

Originally Posted by elicausi

Can Dianan mid pipe be installed without a lift by a DIYer? I'm not quite an idiot, but not too far off when it comes to mechanics.

FazAttack · 06-20-2017, 01:49 PM

Quote:

Originally Posted by riskmaker76

Its a simple misalignment of your exhaust... go back and have them adjust it

The only way to test it is get it on a lift and push up on the entire exhaust and see if it hits... Pushing on the mufflers itself is useless... To do it right they would have had to taken down / unbolted everything..

Thats why I just recommend getting the dinan mid pipe... an idiot can install that.. the other way your at the mercy of whoever is doing the cutting and welding.

i had the dinan midpipe installed and have this noise

2turboBMW · 06-20-2017, 09:17 PM

I can also hear and feel the midpipe banging on the under carriage on the front passenger side. Taking it to get fixed later this week.

NYC_340i · 06-22-2017, 09:35 PM

Quote:

Originally Posted by 2turboBMW

I can also hear and feel the midpipe banging on the under carriage on the front passenger side. Taking it to get fixed later this week.

Let me know what happens! I've been busy lately so I haven't been able to get it checked out but it's getting really annoying haha

2turboBMW · 06-23-2017, 08:05 AM

Quote:

Originally Posted by NYC_340i

Quote:

Originally Posted by 2turboBMW

I can also hear and feel the midpipe banging on the under carriage on the front passenger side. Taking it to get fixed later this week.

Let me know what happens! I've been busy lately so I haven't been able to get it checked out but it's getting really annoying haha

Trying to bring it in tomorrow. Will let you know.

2turboBMW · 06-26-2017, 07:26 AM

Brought it in on Saturday. The said they "adjusted a bolt" and that fixed it. Seems to be fine now.

06-11-2017, 11:24 PM	#1
NYC_340i Lieutenant 208 Rep 547 Posts Drives: '20 M340i xDrive, '11 X3 28i Join Date: Jun 2011 Location: NYC iTrader: (0)	Exhaust Thuds after Resonator Delete? Hello everyone. I've had both the resonators removed on my '16 340i xDrive a month ago and I was really in love with such a simple change. But that only lasted about 2 weeks and ever since I've been hearing some thuds coming from underneath the car every time I hit a moderate to big size pothole. It sounds like the exhaust is hitting the underside of the car and it happens more often if the right 2 wheels hit the pothole over the left 2. Living in NYC where the roads are not that great doesn't help either. I checked underneath the car and cannot find any indication of something hitting the exhaust. I initially thought it would be the brace in the center of the car since the clearance is less compared to stock with the new stainless steel pipe but there seems to be no damage there. If I grab the exhaust tip and shake it hard I can hear it start to make the same sound. Oh and I checked both hangers on the mufflers as well as the bolt in the front and the connection to the downpipe and they all seem to be fine. Anyone have any idea what it can be? I'll try to get it on video if that will help. Thanks in advance.
	Appreciate 1 2turboBMW115.50 Tweet Quote

06-12-2017, 08:34 AM	#2
PeterA90 Private First Class 86 Rep 151 Posts Drives: 340xi Join Date: Dec 2016 Location: Chicago iTrader: (0)	It's not tightened properly
	Appreciate 0 Quote

06-12-2017, 06:28 PM	#5
SingleturboVert Second Lieutenant 49 Rep 202 Posts Drives: E93 335i Join Date: Jan 2017 Location: USA iTrader: (0)	Report back
	Appreciate 0 Quote

06-12-2017, 08:02 PM	#7
perryo91 Captain 373 Rep 937 Posts Drives: 335 Join Date: Apr 2009 Location: Florida iTrader: (1)	Im looking at getting my resonator / resonators deleted. What should I mention to the exhaust shop to make sure they do this? Would I need to come back for a "Follow up appointment" to tighten it when its warm? Anyone got some tips? Thank you! __________________ Hi
	Appreciate 0 Quote

06-13-2017, 08:47 AM	#9
riskmaker76 Lieutenant 126 Rep 484 Posts Drives: 440 xi MPPSK JB4 Join Date: Aug 2016 Location: Socialist People's State of NY - Long Island, NY iTrader: (0)	Its a simple misalignment of your exhaust... go back and have them adjust it The only way to test it is get it on a lift and push up on the entire exhaust and see if it hits... Pushing on the mufflers itself is useless... To do it right they would have had to taken down / unbolted everything.. Thats why I just recommend getting the dinan mid pipe... an idiot can install that.. the other way your at the mercy of whoever is doing the cutting and welding.
	Appreciate 0 Quote

06-20-2017, 09:17 PM	#14
2turboBMW Second Lieutenant 116 Rep 201 Posts Drives: 340i Join Date: Jun 2013 Location: NYC iTrader: (0)	I can also hear and feel the midpipe banging on the under carriage on the front passenger side. Taking it to get fixed later this week.
	Appreciate 0 Quote

06-26-2017, 07:26 AM	#17
2turboBMW Second Lieutenant 116 Rep 201 Posts Drives: 340i Join Date: Jun 2013 Location: NYC iTrader: (0)	Brought it in on Saturday. The said they "adjusted a bolt" and that fixed it. Seems to be fine now.
	Appreciate 0 Quote