I just took my supercharger off and took a look at the rotors through the hole in the bottom where it connects to the intake manifold....and they are absolutely covered in a think layer of soot, or some black, dried oil substance. Should these be cleaned while I have it off?

No, do not clean that off. That'* the coating and should be there.

X2

Clean that off and your SC'r is screwed!

X3

No touchy the rotors.

Good to know, thanks. But the reason I ask is half of it is coming off and I can see bear metal. Does it affect performance in any way?

To a point, it allows a gap between the rotors so it'* less efficient.

The SC on the OP'* 92 was the first version of the M62. This version came with uncoated rotors. I am in agreement about not cleaning the rotors as it would increase the tolerances between the rotors and make the SC less efficient.

92-93 M62 uncoated rotors
94-95 M62 coated rotors
96+ M90 coated rotors.

Ok now your confusing me. If my year of m62 shouldn't have a coating, then why is everyone saying don't clean them, if whatever is on them isn't even supposed to be there. There is definitely a teflon-type coating on the rotors, but a lot of it has worn off (especially in the middle) and the bear metal of the rotors is exposed. Here are some pictures.

Your year came with a non-coated rotor according to all the facts and SC'* I've ever seen from your year. Being that the casing itself is slightly different, unless your motor was swapped, the charger shouldn't have coating on the rotors.

Everyone else is telling you they have coating, because all the superchargers had coating except 92 and 93. Most folks don't have a lot of experience with the 92 and 93 chargers. The other thing I'm saying is things happen, engines get swapped and in general terms your rotors shouldn't be coated.

Clearly though... don't ever clean rotors. It'* a bad idea. First off you will clean the grease out of the needle bearings that the rotors rely on to spin. Secondly you'll see all the coating come off like I did.






At the time the average supercharger for my car was costing over $500 used from friends. It was a bad day.

I only bought this car a year ago, so I don't have too much history on it, but it definitely seems something has been swapped if I have coated rotors, thanks for the info.