Has anybody ever had this happen after having a supercharger pulley installed?

After a few hundred miles of doing the M7 pulley, the tensioner is really working and the noise is unbelievable, plus a significant build up of rubber (belt) dust in the area. The car only has 6K miles on it, and the stock belt in use.

The distance between the rear edge of the pulley and the supercharger housing is ¼ inch. Is this the correct distance?

Thanks

 

If you are talking about the rear flange that the belt rides in, yes. If there is a quarter inch between the inner part that the pulley clamps to, no. Make sure the belt is running on all the accessory pulleys and not hanging out of some of the grooves. The stock belt should work fine as long as it is not stretched. I don't know if the belt can be threaded incorrectly, but it might be possible. What do you mean by "the tensioner is really working?"

Steve

 

I know that the tensioner needs to be in constant motion as it works to keep tension on the belt....so I guess that "Really Working" is a relative term. So we can ignore that statement.

The belt is running in the center of all the pulleys with a bit of side to side motion (2-mm) and is correctly installed.

There is just this loud clacking when the engine is running, and I need to find out what is causing it. The 1/4 inch measurement is from the rear of the M7 pulley to the supercharger housing. I am asking about the measurement as this would give some indication of whether or not the pulley is on the shaft in the correct position.

Thanks.

 

There is the inner part and the outer part of the two piece pullley. You should not see any space between the inner part and the supercharger and you will have about a quarter inch between the outer part (the part the belt runs on) and the supercharger. If it wasn't torqued down properly it might spin on the supercharger shaft, but it would probably move away from the supercharger also. The belt rubber usually indicates something is out of alignment and rubbing so I would suspect the new pulley. Find out if the tensioner was removed to do the install and make sure it's bolts are tightened down and it's not flopping around.

Steve

 

Steve:

I checked all the bolts on the tensioner & M7 pulley. Everything is tight. The 1/4 inch measurement between the back surface of the pulley (where the belt rides) and supercharger housing is what I have so it sounds like the pulley is positioned correctly.

I am not sure if the shop that installed the pulley removed the tensioner, but they are BMW Certified and have done Alta pulleys in the past with no problem. They did say that they would NEVER install another M7 as it was a difficult pulley to install.

I am waiting for M7 to reply to my emails but am getting the feeling that I will end up getting "stuck in the middle" between vendor and installer. We shall see what develops, but in the end.....I payed my money and just want the thing to work. Meanwhile the car sits useless.

 

You should try to call Peter, you'll get a much faster response.

As for the shop that installed the pulley, doesn't sound to me like they are too bright. The M7 pulley is self-centering, like just about every other pulley on the market.
If they had the proper pulley tool, they shouldn't have had to remove the tensioner.

 

I have installed Alta, M7 and Cravenspeed pulleys and I see almost no difference in the install difficulty. I have installed half a dozen M7s without a problem so I don't know what they were having problems with. If the belt is shreading on the edge, then I'd say something in the belt line is out of alignment. It might also be that the belt is bad enough to have something hanging off it causing the noise. If the belt was damaged during removal or installation that might be the only problem. I am running out of ideas, but you might possibly take the wheel liner out to get a better look at the belt. You can call me at (415) 265-5562 if you want to talk directly.

Steve

 

Difficult to install scares me too. Like how? Bigger hammer or larger pry bar? I'm curious if the tensioner might have been overextended/bent dampner started leaking. The noise is it metalic sounding? Does it do it at idle? The more info the better.

 

Thanks for posting guys:

I took the wheel and fender well shroud out for a better look. I checked the pulley Allen bolts, tensioner bolts, and crank bolt …all are tight. After cleaning off the black rubber dust in the area I looked at the belt and cannot see any damage. At idle the belt looks to be running on the inside edge of the M7 pulley although NOT riding over the lip.

The clanking noise coinsides with the tensioner pulsating and if I shot a little bit of belt dressing on the belt…the noise goes away for a minute but returns.

The Mechanic showed me the problem he was having with the first pulley. The shaft collar could not be pressed far enough into the pulley for the Allen bolt threads to grab even after a bit of light filing on the “collar finger” edges. We called Peter and he sent another pulley down asap.

I got a call to come pick the car up the next morning and the shop owner did not elaborate on the problem only focusing on the fact that I tied his lift up for 2-day!

I am hoping to get some direction from M7 and would like them to look at it…but a 130-mile trip on the freeway has me wondering “what if the belt lets go?”

 

Where are you seeing this side to side movement? At the lower idler pulley(between the alternater & crank)?
Look above the curve of the tensioner arm (on mine an '03 there is an alignment stud for the upper engine mount poking down over the curve of the arm) Getting over zealous with the tensioner tool can bend/break the arm by hitting that nub. Any marks there?
The new pulley looks like its stationary? no slight wiggle?

 

I will check that out.

The SC pulley is rock solid running straight.

 

You may need a shorter belt if the tensioner is bouncing off the supercharger pulley. That might make the clacking noise and cause the belt dust.

Steve

 

I'd vote for the shorter belt as well. The dust from the belt is not normal - if not mis-aligned then probably slipping. The belt dressing would temporarily eliminate the noise from the slipping, but not the real problem. How much of the tensioner "strip" is sticking out? Can you see any of the holes?

 

I recently did a pulley install abt 5 days ago on my MCS. No clacking sound, and I replaced my belt with the belt spec'd for the JCW kit. Everything runs smooth and fine.

 

The metal strip that sticks up out of the tensioner is the wear indicator. The lower round hole is the caging hole which is used for caging the tensioner during belt replacement. The elongated hole above is the indicator. If that hole is not visible, then the tensioner is out of range and won't exert the proper tension on the belt. Also, we've found lots of worn bushings on the tensioner strut as well. Your problem is most likely belt tension. We always use a shorter belt on pulley installs. Cheers.