gtp is sick =[

**NegativeOne13** · 06-28-2011

You don't need to ask the dude... just stop the guy at a stop light and tell him to pop his hood. Then you would know what it sounds like.

**NegativeOne13** · 06-28-2011

And like I said before when your going downhill your torque converter is engaged. When you push on the brake it disengages it. So the RPM fluctuation is normal and you can feel it as well. But it shouldn't thud.

**Scottydoggs** · 06-28-2011

if you can post a video of the noise, it may be something someone has heard before.

**PhunnyJesta** · 06-28-2011

YouTube - ‪PICT2717‬&rlm;

different vid without me trying to blow it up xD

I was wrong about grinding/scratching coming from the snout with the stethoscope, i had the stethoscope on the side which made it seem like there was grinding but when I have it straight down on the snout it goes away so it might not be the supercharger after all. I do hear a vacuum leak now somewhere in the upper left of the engine bay. Letting the engine cool down for a little

**TLSheff** · 06-28-2011

Originally Posted by PhunnyJesta

Last week I put on a new-to-me 3800performance ported m90 s/c and it ran good but I still have this feeling of lack of power....

Define this "new-to-me" part. Was it used by someone else, or is one directly from 3800 that THEY rebuilt?

Other than what I could describe as a possible coupler issue if it even could be that, yours sounds about normal.

Granted that IS based on my tiny lil computer speaker at work which may or may not accurately sound out the problems you in fact are hearing, yours sounds like mine and mine is running like a top.

BTW if you didn't know, if you put on the K&N intake at the same time as the supercharger kit, the intake makes more noise than a stock air box, you can hear the supercharger actually spinning at idle, makes a somewhat nasty growling sound if your not use to it. Could this be whats making you nervous??? worried me first time I did but when I put the stock air box back on it was back to quiet, and info on here educated me to the fact that everything will be okay.

**PhunnyJesta** · 06-29-2011

new-to-me as in its a rebuilt supercharger i bought from 3800performance, I believe its just a rebuild, at least thats what i got from the text anyways

3800 Performance M90 Supercharger Kit: 3800 Performance

intake I did a year ago and that sound threw me off completely haha I wasnt expecting it to be as loud and mean as it is lol

After poking about every little thing in the engine bay with the stethoscope (i even listened to a spark plug wire without realizing it haha) I cannot find anything that is related to the rough noise I am hearing. I want to say it kinda sounds like a bearing is starting to go bad but everything sounds fine as far as the supercharger. But i did find something else that strikes me as odd. Putting the stethoscope to the fuel rails the left side sounds throaty and more aggressive but the right side sounds A LOT milder. Its a day/night difference between the sounds they make. I just found out that there is a GM dealer around my area that will do free quick check diagnosis where they just look and listen. Ill be taking it down there next tuesday and see what they have to say and then run away before they try selling me over priced parts lol