Supercharger-like whine from engine? 2006 Z4M

J

jontZ4M

Member
Hi guys

I've been increasingly noticing a supercharger-like whine from my car.

First I assumed transmission, but I pretty much ruled this out when:
A) realising that idle is present when car is static.
B) pressing/releasing clutch makes no difference to whine.

Next I assumed aux pulleys, so I removed aux belt and AC belt:
A) all pulleys feel fine
B) car still makes whine with belts removed

So as far as I'm aware that rules out transmission and aux area of engine.

Other things of note:
- whine is directly linked to RPM
- hard to locate but gut feeling is it's coming from front/top of engine. (I've had a listen around this area with stethoscope but can't confirm it).
- car is 51k miles. I'm the first "enthusiast" owner so I doubt it's had any kind of re-built work.
- no other problems or warnings etc.

What do you reckon guys?

Thanks
 
Someone install a Vortec while you wernnt looking?

All BS aside, you removed the belts you said and still the whine? I'd prob look at the chain guide then?
 
Vanne said:
Someone install a Vortec while you wernnt looking?

All BS aside, you removed the belts you said and still the whine? I'd prob look at the chain guide then?
Click to expand...
Checked, and no massive supercharger added sadly. Will investigate chain guide thanks.
 
Hi,
I had a similar noise to what you describe but on an n52 (3.0 not the M 😭).
Had the alternator replaced under warranty as part of the investigation, which didn’t solve it.
It turned out to be the oil filter vibrating. It wasn’t seated properly in the housing lid so could vibrate.
Not sure if it’s a similar set up in the M but could hopefully be an easy fix!

Is the car new to you and has the noise been there since you got it?
 
bigwinn said:
Can you grab a video
Click to expand...
OK got the vid. This is a cold start. It's a bit weird as you can't hear it for the first minute or so but gets louder as vid goes on:



0-1 min: can't really hear it
After 1 min: can hear it now
After 2 mins: getting louder
After 3 mins: now the loudest thing about engine
After 3.5 mins: revving engine

chris719 said:
I had a noise like this a bit, when cold only, it was either the water pump bearings or idler pulley. Replaced it all and it went away.
Click to expand...
Def not that as I tried running without the Aux belt and still made the whine.

MHZ4C said:
Hi,
I had a similar noise to what you describe but on an n52 (3.0 not the M 😭).
Had the alternator replaced under warranty as part of the investigation, which didn’t solve it.
It turned out to be the oil filter vibrating. It wasn’t seated properly in the housing lid so could vibrate.
Not sure if it’s a similar set up in the M but could hopefully be an easy fix!

Is the car new to you and has the noise been there since you got it?
Click to expand...
It's certainly got worse since I've had it. Can you listen to vid above and see if that sounded like yours please?

PDJ said:
Try without your wife in the car
Click to expand...
Hugely valid point BUT have ruled that out buying her beauty gifts etc.
 
Sounds the same as mine. I’ve just been through a few videos I’ve made during various episodes of paranoia, dating back to 2014, (from around 37k to 84k) and it’s had a similar whine all along.

I’ve just put it down to the PAS circuit or the drag on various components-pulleys. No idea if that’s correct but it’s never given me an issue in all these years. I do have a ticky pulley that shows up when cold but that’s a recent thing and hasn’t changed the whine.
 
From memory it sounds similar to what I experienced when the oil filter wasn’t seated properly. Increased in pitch as engine revs increased. It was a while ago though.

The s54 oil filter housing looks different to the n52, I had to click the filter into the lid on the n52. Maybe put a new filter in to be sure it’s not damaged & is seated properly? Or just do the oil & filter if it’s not far off being due.
Won’t hurt and would rule that out.
 
MHZ4C said:
From memory it sounds similar to what I experienced when the oil filter wasn’t seated properly. Increased in pitch as engine revs increased. It was a while ago though.

The s54 oil filter housing looks different to the n52, I had to click the filter into the lid on the n52. Maybe put a new filter in to be sure it’s not damaged & is seated properly? Or just do the oil & filter if it’s not far off being due.
Won’t hurt and would rule that out.
Click to expand...
OK will order new filter and try.

Got a bit more info - had a second go with a stethescope today. This time without a 3 year old hanging off my arm so I could actually concentrate. You can hear the whine when touching more of less anywhere at the top top the engine and even the top of the transmission bell housing. Generally the thicker the bit of metal the quieter the whine. BUT I found a REALLY loud whine when touching one of the alloy protrusions from the top front on the engine(I assume they are VVC component covers). It was the one on the intake side.
 
I've just been talking to ChatGTP about it.

It suggests a couple of inexpensive things to further rule stuff out:

1) remove and dissect oil filter and look for sparkles or plastic or whatever. Can tie this in with the above idea ^^

2) replace timing chain tensioner. Apparently fairly easy job and would rule that out.
 
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