: Dinan Vortech Sound Paranoia

02-19-2008, 11:35 AM
Hi folks!

I've done quite a bit of searching on this board and in general (on the Internet, but not under my couch) and thought I'd ask this despite finding some partially pertinant information and despite my common sense which tells me this is impossible to accurately diagnose sight/sound unseen/unheard. Might be useful to others as I go through the troubleshooting process (if there is indeed a problem at all). Dig the email I sent Vortech Engineering below for details, and please let me know if my description rings any bells. Also, if anybody has sound clips of their similar units at idle and through the rev range I would appreciate hearing them. Just want to make sure I don't feed my S52 a shrapnel salad!

Paste of email to Vortech:

Hello. Just shy of three years ago I had a Dinan Vortech unit installed on my 1999 BMW M Coupe. Since then I've put only about 2000 miles on the car. I've never run it in below freezing temps and only drive the car on nice weekends. This past Saturday qualified so I took the car out and noticed what I think is a new noise that I believe to be coming from the supercharger. At about 4K rpm while driving it seems there is a faint consistant screeching (like someone using a metal grinder to sharpen a knife) that I can only hear with the window open. At idle, things seem normal with the usual whistle of the supercharger. No rattling or anything like that. I'll try to get a sound clip and will check the supercharger for leaks or pulley play. I'll also verify that the sound is coming from the supercharger with the ole block of wood or screwdriver technique, assuming I can reproduce it while under the hood (I'll crank the alternator load and rev the engine). Just wondering if you have any sound clips or description of the sounds a failing unit might make. I'm worried the sound might be that of the impeller rubbing the housing due to bad bearings. Any suggested addional diagnostics I should run? Thanks!!!