Rattle when decelerating (exhaust?) Help needed

TurboBimmer · 04-08-2009, 03:59 AM

Hello.

I'm soon gonna get a tune (JB+), so I want to make sure everything is alright on the car, or if I need to take it to the dealer before installing the JB.

Thing is, there is a rattling noise which can only be heard on the outside of the car, when decelerating the engine from say 2-3k rpm. It can be heard both when driving and in neutral. Sounds a bit like something was loose inside the exhaust.

Any guess what it could be? Only clue I've found is that it might be the valve in the left exhaust. But the noise seems to come rather from the "middle" of the car.

It's a E92 335i AT from 10/2006.

joec500 · 04-08-2009, 10:52 AM

I have this same sound...to my knowledge it's the exhaust shutting the valve so there is no drone at lower RPM's. It probably "sounds" like it's coming from the center of the car because the sound is probably resonating up the exhaust system.

I wouldn't worry about it.

04-08-2009, 03:59 AM	#1
TurboBimmer Lieutenant Colonel 79 Rep 1,617 Posts Drives: F82 M4 Join Date: Mar 2009 Location: Luxembourg iTrader: (5)	Rattle when decelerating (exhaust?) Help needed Hello. I'm soon gonna get a tune (JB+), so I want to make sure everything is alright on the car, or if I need to take it to the dealer before installing the JB. Thing is, there is a rattling noise which can only be heard on the outside of the car, when decelerating the engine from say 2-3k rpm. It can be heard both when driving and in neutral. Sounds a bit like something was loose inside the exhaust. Any guess what it could be? Only clue I've found is that it might be the valve in the left exhaust. But the noise seems to come rather from the "middle" of the car. It's a E92 335i AT from 10/2006. __________________ Performance Seats, Exhaust, Splitters, Pedals, Steering Wheel / RB Turbos / M3 CF Roof / Brembo GT BBK 355/345 / Rollcage / Forge FMIC / Quaife LSD / Öhlins Road & Track / M3 Suspension Parts / Solid Subframe Bushings / Vorshlag Camberplates / Megan Racing Toe Links / LeatherZ Gauges / Extended M3 DCT Paddles / ER Sports OC / AR OC / Aux Radiator / AR DPs / Alpina TCU / COBB Pro-Tune
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04-08-2009, 10:52 AM	#2
joec500 Brigadier General 125 Rep 3,004 Posts Drives: it has 4 wheels Join Date: Jul 2008 Location: San Francisco iTrader: (10)	I have this same sound...to my knowledge it's the exhaust shutting the valve so there is no drone at lower RPM's. It probably "sounds" like it's coming from the center of the car because the sound is probably resonating up the exhaust system. I wouldn't worry about it.
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