Very strange engine noise!

[lusomini]

Ok, this is freaking me out! Maybe some of you can identify this

My MCS is now 1 year and 6 months old. I've been noticing that there’s an engine noise which seems to be getting more and more noticeable.

It's like a "Whooooooo" which is heard above the engine noise. It's more pronounced when cold but: if I start the car with engine still hot and then let it idle, it's normal. If I rev it slightly to 1500 RPM the "Whoooo" noise appears (similar to a engine/AC fan noise but more like a "whine/moan"), if I rev it up a little bit more to 2000 it gets more pronounced even, sounds like almost a moan! When I live the throttle and it gets back to idle it does a loud "Whoaaaaa" and then it settles idling without any noise. I opened the bonnet and it seems to come from the supercharger area...

Don't just laugh at my attempts to describe the noise, please help if you can

[Ian Clark]

The supercharger whines. Thats what it does along side providing lots of power. There are hundreds of threads on these forums mentioning the Supercharger whine and how fantastic it is.

If you think it's something else than the Supercharger, contact your dealer, you're still within warranty.

[lusomini]

Thanks for the input. Hummm, I know how a supercharger works I'm quite familiar with the "zing" when you mash the throttle and give it some. That's not what I'm talking about.

Just seems to be getting more pronounced as the miles/kms pile up, and appearing briefly when you get off the throttle, just before the car comes to a halt . Is this normal?

[sergio rollerfunk]

...time to take it down to the dealer.

What's the actual mileage/kms. on your MINI? Do u have any mods that could have caused that strange noise? As I deduct from your explanation, It could be a supercharger problem...have u noticed any loss in performance or a change on your engine's regular behavior/drivability?

[lusomini]

15K/24K miles/kilometeres. And it's very well treated. No mods whatsoever. I haven't really noticed any loss of performance, but if it has lost a little performance I'm not sure I would be able to detectet it has I live day to day with the car and if something is degrading (not catastrophicaly) I would not noticed it...

[Mustang7302]

It could be the intake you hear. Try to see if your filter is dirty or causeing any kind of restiction or wierd air flow (turbulance).

[wmd]

There have been previous threads on this subject. There has been a problem with collapsed pcv hoses on 'S' models.
http://www.mini2.com/forum/showthrea...threadid=40907
http://www.mini2.com/forum/first-generation-faults-fixes/26574-whistling-supercharger-any-ideas.html
Also, I have notes on service measure M11-200-04 that affects 07/02 to 07/03 Cooper S models that replaces the PCV hose with a stiffer one. Date on the SM is 02/10/04 and it does not apply to ONE or COOPERs.

[minitek]

I thought this noise was there because I had installed a CAI. But after testing with the stock intake box it still moaned! I've already made an appointment with the dealer. I'll let you know how it goes... (and it does sound like Jim Carey - HMMMMmeeeuuuuuuuuuuhhhh!)

You can hear the noise between gear changes here:
http://www.maxvelocityvideos.net/vid..._mini_dyno.mpg

[lusomini]

Ok, as wmd said it's the small hose on the supercharger intake (left side). When I start the car from cold the noise is constant (almost aircon like but more like a "moannnn"). If I press the hose the noise changes. It is "strangled" in the middle and with a bit of oil soak(?) Problem identified. Hope it can help other with the same problem.

Wen to the dealer but they didn't have the hose in stock(!). They wounded the tube in some tape wich of course only made it worst, the rubber hose is evem more choaked now! Now I notice the noise everytime I back off the throttle. They ordered a new one but I'm looking if there's a better aftermarket item or as BMW developed a better one by now?

[petecrosby]

I have the same issue. On my car (1 year old MCS with 21000 miles on it) the problem just appeared in the last few days. It seems to be ambient heat related, happens when in stop/go traffic on a warm day (>85 F), and will go away once I get out of traffic and moving.

The noise, for me, is a low pitched whistle or "woooooooooo" starting at about 3K RPM.
When it happens the noise is evident in any gear or neutral, clutch in or out.

My understanding is that Mini (BMW) has a newer style replacement hose which is stiffer rubber.