Strange noise on right handers...an obscure one

Tony B · 09-28-2024, 07:14 AM

I am getting a "strange noise" apparently coming from the engine whenever I turn right at city speeds.

I first noticed this when negotiating a fairly large roundabout (clockwise, I am in the UK) at about 20mph.

At first I thought it was the heater fan bearing, but it is still apparent even with the fan switched off.

It does not happen turning left, or going straight ahead.

It is definitely not:

1. power steering noise (not a sound from the system when turning the steering wheel while stationary, or crawling speed), or
2. differential noise - the sound is coming from under the bonnet.

One thought I had - recently the plenum was removed (by dealer) in order to replace the water thermostat. On pick-up, I did notice a slightly different engine speed-related noise - it almost sounded like front centre speaker noise, at lowish revs (less than 2.5k)

My thought - the plenum re-install is not right, and maybe one of the throttle body connections at the back of the engine, or the idle speed control pipe is not properly connected, and this only becomes apparent with some movement of the engine on its mounts, caused by the g-force of turning right? The mounts themselves were replaced about 10 k miles ago.

It is all so awkward to reach, I fear I might have to go back to the dealer. And get some more, new problems....

Helmsman · 09-28-2024, 04:32 PM

The throttle connections is easy to check that they are seated, so is tighting them up if not. One of these for a tenner is perfect for the job: https://www.biltema.se/bil---mc/bilv...RoC8GEQAvD_BwE

Redd · 09-28-2024, 06:45 PM

It might be useful to have a video of this strange noise.

serranot · 10-08-2024, 01:31 PM

Front wheel bearing?

Tony B · 07-20-2025, 11:28 AM

Another slow follow-up from me.
(A bit of a habit, unfortunately)

After a lot of dismantling stuff, replacing numerous components (pulleys, fans, a wheel bearing) this was tracked down to......

A (dead) snail shell wedged between the underfloor and a heat shield, which caused some contact between the engine/transmission and the heat shield, and therefore a noise path into the car, whenever some lateral g caused the engine to move on its mounts.

Yeah.

Honest.

True story.....the noise has gone now!

09-28-2024, 07:14 AM	#1
Tony B Lieutenant 116 Rep 468 Posts Drives: 2012 E92 M3, MW, ZCP, 6MT Join Date: May 2009 Location: UK iTrader: (0)	Strange noise on right handers...an obscure one I am getting a "strange noise" apparently coming from the engine whenever I turn right at city speeds. I first noticed this when negotiating a fairly large roundabout (clockwise, I am in the UK) at about 20mph. At first I thought it was the heater fan bearing, but it is still apparent even with the fan switched off. It does not happen turning left, or going straight ahead. It is definitely not: 1. power steering noise (not a sound from the system when turning the steering wheel while stationary, or crawling speed), or 2. differential noise - the sound is coming from under the bonnet. One thought I had - recently the plenum was removed (by dealer) in order to replace the water thermostat. On pick-up, I did notice a slightly different engine speed-related noise - it almost sounded like front centre speaker noise, at lowish revs (less than 2.5k) My thought - the plenum re-install is not right, and maybe one of the throttle body connections at the back of the engine, or the idle speed control pipe is not properly connected, and this only becomes apparent with some movement of the engine on its mounts, caused by the g-force of turning right? The mounts themselves were replaced about 10 k miles ago. It is all so awkward to reach, I fear I might have to go back to the dealer. And get some more, new problems.... __________________
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09-28-2024, 04:32 PM	#2
Helmsman Major General 5484 Rep 7,657 Posts Drives: 2011 AW E90 M3 ZCP Join Date: Mar 2014 Location: Stockholm, Sweden iTrader: (0)	The throttle connections is easy to check that they are seated, so is tighting them up if not. One of these for a tenner is perfect for the job: https://www.biltema.se/bil---mc/bilv...RoC8GEQAvD_BwE
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09-28-2024, 06:45 PM	#3
Redd Brigadier General 5039 Rep 4,842 Posts Drives: 2010 BMW E92 M3 Dakar Edition Join Date: Jul 2015 Location: Malaysia iTrader: (0)	It might be useful to have a video of this strange noise.
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10-08-2024, 01:31 PM	#4
serranot Lieutenant 348 Rep 505 Posts Drives: Nothing Now Join Date: Mar 2011 Location: Middletown, MD iTrader: (0) Garage List 2011 BMW E90 M3 [10.00]	Front wheel bearing?
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07-20-2025, 11:28 AM	#5
Tony B Lieutenant 116 Rep 468 Posts Drives: 2012 E92 M3, MW, ZCP, 6MT Join Date: May 2009 Location: UK iTrader: (0)	Another slow follow-up from me. (A bit of a habit, unfortunately) After a lot of dismantling stuff, replacing numerous components (pulleys, fans, a wheel bearing) this was tracked down to...... A (dead) snail shell wedged between the underfloor and a heat shield, which caused some contact between the engine/transmission and the heat shield, and therefore a noise path into the car, whenever some lateral g caused the engine to move on its mounts. Yeah. Honest. True story.....the noise has gone now! __________________
	Appreciate 0 Quote