Since some days ago I can hear a whistling sound some seconds after starting the car (Mini Cooper non-S 2010 90k)

The sound is coming from the engine bay, passenger side, maybe drive belt zone.
The sound is exactly after the "mechanical" sound on the engine. (mechanical sound: is that sound that you can hear cleary if you put the car on ignition position without starting the engine. It seems the car adjusting something).
The whistling sound is always with the engine on idle, or maybe I can only hear it with the engine on idle.

I have readed many threads here and other forums (MINI, BMW) with this same behavior but I can't find the final origin nor resolution

 

Important information omitted: Last month the valve cover gasket was replaced (OEM) due to a minor leak.
Two weeks ago, engine oil was changed and it is a little above its maximum.

After reading again on internet, I will check again the noise area and will test the PVC.
If there is an issue with the PVC membrane (and the valve cover is 100% OK) I will buy the replacement for my N16 engine from ECS Tuning

https://www.ecstuning.com/b-hamburg-...54v-space-~ha/

After researching I could find some guides on forums and on YouTube too about changing this membrane in N18 engines (very easy) but I can't find the same for the N16...

 

Last night I could check 2 things:

1) The first engine start in the morning is not doing this noise at all. The noise is only after using the car. If after using the car I turn it off and then on immediately, the noise always appears on idle. It seems it is directly related to the car/engine temperature.

2) The noise seems to be coming from the drive belt area, taking out the oil dip stick don't change anything related to the noise. I checked the PVC membrane cover area and the valve cover gasket and it seems to be 100% OK.

I have changed the multi rib belt in no more than 15k miles ago (replaced with the Gates one).
Maybe I should replace the multi rib belt again?
Is there any safe way to test if it is the drive belt doing this?

 

I have an R53, when my car made that type of sound, it was the Idler Pulley

 

Thank you for your comment gumbedamit, after reading you I was researching about the pulley on my R56 base.

I could discover that the "mechanical sound on the engine" (comment 1) is the car moving the friction wheel to connect the crankshaft pulley with the water pump pulley.
Then, if I can only hear the whistling noise some seconds on idle with the engne in warm condition and after the ECU moved the friction wheel, I'm starting to believe that there is something bad with the drive belt or some problem/misalignment on the friction wheel or the water pump pulley.

I will talk with the BMW Indy shop tech about this, surely I will try fixing this by changing the drive belt before changing anything else if the pulley seems to be in good condition (no wear/misalignment)

 

I had rattling noise in my N16 engined Cooper LCI caused by the friction wheel assembly vibrating (due to melted rubber residue within the tracks of the crank shaft pulley). There was also a metallic, high frequency sound (almost like a turbo whine), caused by the friction wheel's baring. Before finding out that the rattling is caused by the rubber residue in the crank wheel, I changed the friction wheel assembly. While it continued vibrating until I also changed the crank shaft pulley), the high frequency whine was less.

The following video documents the original state. If you listen to it on good headphones, you will hear that the high pitch whining noise disappears when the friction wheel pulley is held back.

Both my original and the replacement friction wheel (both OEM and manufactured by DAYCO) run smoothly and with no issues besides the noise (which is more on the old one as one can hear in the two follow up videos I posted). If your friction wheel is louder or doesn't run smooth when pressured, the baring will probably be worn. The wheel itself is sold separately (at least aftermarket here in Europe), even though BMW/Mini do not list it as a separate part (they will only sell you the whole friction wheel assembly).

By the way and imho: getting the friction wheel assembly out is a PITA.

PS.: Is your MINI a US version? According to post here on NAM, US versions have the friction wheel assembly drive the waterpump pulley at all times.

 

Thank you so much for your comment and video.

My MINI is EURO version and it's running a DAYCO drive belt currently.
Now I can hear it less than 10 seconds while the car is warm (only on idle and when I turn off the car).

Surely as you said, there is an issue whit the friction wheel too. I will check for the friction wheel, an OEM drive belt is already on the way.

 

If the noise itself doesn't annoy you (too much), you could check how easy and smooth the friction wheel pulley turns. The serpentine belt does not have to be removed, nor its tensioner put into service position:

1. remove the front right wheel
2. remove the fasteners in the front half of the wheel arch cover (or all if you mind folding the cover)
3. fold the front half of the wheel arch cover outward and back (or take it out completely)
4. pull the latch at the top of the friction wheel assembly to make sure the friction wheel pulley is unlocked (i.e. not pulled towards the waterpump pulley).

You can then turn the friction wheel pulley while trying to apply pressure on its bearing. If it turns smoothly, I wouldn't change it. Mine had the whine from when I bought the car. Three years and about 20.000 miles later the sound didn't get worse. When I replaced it last summer I compared it with the replacement pulley and couldn't tell a difference. Both turned equally smooth. And as already stated, the replacement isn't absolutely quiet either.

Here the detailed instructions to remove the friction wheel assembly (which also show the unlock latch I mentioned above):
https://www.newtis.info/tisv2/a/en/r...ement/D7XrxsmB

Be warned though! Accessing the three fasteners of the friction wheel assembly is only possible with a very (!) low special socket in combination with a ratcheting wrench. The one listed in the instructions is the 10mm WERA 8790FA which needs an 11mm ratcheting wrench (I would recommend one that can flex AND allows adjusting how "tight" the flex is). Using the socket's 1/4" drive with a regular ratchet results in too much combined height (it doesn't fit, yes, I tried). I also had to remove the top right engine mount and lift the engine by about 2 inches in order to access the top two of the three fasteners.

 

Dear, thank you so much for your directions.
I could check the friction wheel and it seems to be in good condition (it turns smoothly and there is no visible damage on it).

I have a new OEM drive belt on the way to check the behaviour with the new one.
The noise is still there.
I will let you know.