E55 irritating supercharger chirp

[Benji1987]

hello all!
I believe it’s a common issue that I eat a chirp when the charger kicks in. If i went for a smaller pulley/remap would the pulley change get rid of it or is there something else that needs to be done?

 

[Gbrowncls55]

I think its usually the clutch rather than the pulley. But can be the belt also

 

[Benji1987]

I have replaced the tensioner and belt when i did the crank pulley but nothing changed. So I’m guessing it’s the pulley or the clutch. Wasn’t sure if anyone had cured it?

 

[simon1966]

My original s/c pulley did this when the clutch engaged. There are ways to stop it with a graphite spray. Never tried it myself as I actually liked the chirp. My chirp disappeared when I had the smaller s/c pulley fitted, so it must be something to do with the clutch plate on the original MB pulleys.

Found a link to this on another thread:

Kontakt-Chemie 207606091242 Graphit 33 Spray 200ml | eBay

BTW - the chirp is harmless so I wouldn't worry about it. Just call it character which the 55K has plenty of!

 

[AMGeed]

I'm in the camp of rather liking that s/c chirp too. But for some reason, mine has disappeared even though none of the pulleys or belts have been changed.
Beginning to miss it TBH

 

[benjy88]

I had the smaller pulley fitted and it got rid of my chirp when it engaged, which I was pleased about as it was annoying

 

[steveskeggy]

Pretty much all of the 55 superchargers do it.
Apparently its because the clutch is, putting it politely, a bit basic.
The chirrup is the sound of the belt slipping on the pulley as the clutch snaps on.
Less of a clutch, more of a switch.
It is a good way of knowing that your supercharger clutch is still working.

 

[Benji1987]

I wouldn’t mind it as much but you get the little hesitant dip in power when it does it. Would you have to remove the pulley to get the graphite spray in there? Can’t see that lasting for very long mind!

 

[AMGeed]

^ No need to remove any pulleys. Just spray the graphite on the inside of the s/c belt as its ticking over.
It's not a permanent fix, but just needs another spray when the chirp returns.