Vibration/noise under WOT in 1st and 2nd?

intoflatlines · 08-29-2015, 02:50 PM

I've noticed that occasionally when I do a WOT run through 1st and 2nd, I will hear/feel a low pitched hum/vibration. Seems to be more noticeable in 2nd. I know this is not a lot of detail but I'm wondering what I can do to start to diagnose it. Clutch slipping? It's not wheelspin. Any ideas?

JCF · 08-29-2015, 06:14 PM

Can you localize where it's coming from? Is it constant or only at certain RPMs?

Have you checked for anything loose in the engine compartment? Both screws and hoses, etc.

Are the motor mounts ok?

StickMon · 08-29-2015, 11:29 PM

If I floor mine at low rpm in 1st or 2nd, it goes through a resonance at about 2500 rpm.
Everything inside the car that's not nailed down goes BZZZZzzzz!!! for about 1 second as it passes through the resonant frequency.

08-29-2015, 02:50 PM	#1
intoflatlines Lieutenant 67 Rep 501 Posts Drives: Z4MR, E34, E30 Join Date: Mar 2013 Location: Chicago iTrader: (0)	Vibration/noise under WOT in 1st and 2nd? I've noticed that occasionally when I do a WOT run through 1st and 2nd, I will hear/feel a low pitched hum/vibration. Seems to be more noticeable in 2nd. I know this is not a lot of detail but I'm wondering what I can do to start to diagnose it. Clutch slipping? It's not wheelspin. Any ideas?
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08-29-2015, 06:14 PM	#2
JCF Second Lieutenant 32 Rep 218 Posts Drives: 07 Z4 M Coupe Join Date: Jan 2015 Location: Charlotte, NC iTrader: (0)	Can you localize where it's coming from? Is it constant or only at certain RPMs? Have you checked for anything loose in the engine compartment? Both screws and hoses, etc. Are the motor mounts ok?
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08-29-2015, 11:29 PM	#3
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	If I floor mine at low rpm in 1st or 2nd, it goes through a resonance at about 2500 rpm. Everything inside the car that's not nailed down goes BZZZZzzzz!!! for about 1 second as it passes through the resonant frequency. __________________ Warning: May contain traces of nuts.
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