Quote:
Originally Posted by iPhoneEngineer
To be clear, I have no objective indication that there is really metal scraping. I'm pretty convinced at this point that the screech is in fact just the belt slipping on cold startup, not the internals of the S/C. Beedub, the video I posted of the screech is a pretty good capture of what it sounds like, and you don't figure that's from the S/C itself do you?
The actual S/C whirs like a finely-tuned jet engine at engine speeds over ~1500RPM. Below that (mainly below 1200RPM) it can be a little rattly as everyone describes to be normal. My suspicion is that the individual power pulses are more distinct and separated at those engine speeds and it causes the gears in the S/C to knock together a bit; a compromise since they are truly designed to run smoothly at extremely high RPM.
Obviously if there is still a screech with the new pulley and proper tensioning, the S/C will be to blame and have to be replaced, but I think that is extremely unlikely to be the cause or to be necessary. Some have implied that these are really fragile pieces of equipment, but it's a freaking vortech supercharger--a mechanical beast that isn't going to be junked by a little bit of belt wobble on less than 5 cold startups I've done.
The car is already in the hands of HG Motorsport who plan to not only replace the pulley and belt, but also at least diagnose the BPV whistle.
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actually i agree with you..... the s/c cant be damaged as the faster you spun it the more noise it would make, so no i dont think it is damaged thinking logically about it, it must just be the "loose" belt creating wierd stress noise on the bearing, these blowers are however noisey on idle, but not enough to be a huge worry...... they kinda make a constant rattle noise but its faint enough to not really hear it with the hood down, some are noiseyier than others, if you youtube noisey vortech v3, you'll get loads of clips of the noises were talking about :-)
when does your new crank pulley come in???
thank god the car is back at the tuners, they and ess will hook you up :-) cant wait for you to get this shitty ordeal sorted like now!!!!