Hi, I thought i'd ask the pro's, what does a broken impeller sound like. I started hearing a chirp which sounded like it was coming from my impeller. I called Vortech and asked what a rebuild would cost and they said if it's a broken impeller it 700 bucks. Is that seriously what it costs? I think i'm gonna call 928 tomorrow and see what they say, i already know they are cheaper, anyone know how much they charge and experience with them. I took a pic, i saw a lot of dirt, gonna try and clean it this weekend, i don't have time to do it right now, or i would of. Any thoughts if this is what the problem is? The chirp noise was on and off and only happened on idle. Here's the pic of it. Looks like it's the problem, but not sure.

 

Doesn't seem to be rubbing, could be your jack shaft bearings. Mine chirps sometimes too so it could just be normal.

 

As far as I can tell from that pic your impeller looks fine... I would lean towards belt squeaking, or bearings.

Belt would be the first thing I check/replace though since it's the cheapest and easiest of the list, and probably the most likely.

 

Well, i bought this kit used. It's been on for 4000 miles now, one track day. When i bought it I bought a new belt and changed out some of the pulleys. So all of the one's on the back side, and the one that turns on the serpentine belt side and turn's the other pulley's that i replaced on the supercharger side. I did put a new belt on both the serpentine side and the supercharger side. I never heard this noise before, sounds like chirp. I'm not familiar with what the scratching impeller looks like, so that's why i ask. That chirp u heard, 350z400rwhp, did it sound when u first put it on, or did it show up after? All that stuff on there in the pic is a lot of dirt, so i didn't know if that was it.

 

I have a vid on youtube with the noise. I cant search it here at work, but it should be linked with the vid in my sig.

You'd know if the impeller was hitting, plus you would see signs of scoring in the volute.

 

thanks str8dum1, i am also at work, so youtube isn't working either. At least until I get home. I was looking for scoring on my volute, but the dirt looks like its covering it, if there was. I'm wondering if it's subtle right now, but then the dirt would be scraped off, so maybe it's not that. I just heard a funny noise coming from my engine. When i popped the hood, the noise was coming from the supercharger. It was a chirping type noise.

 

it could be a bearing, which can lead to impeller walk. I would not continue to drive it though. pull the belts and spin the pulleys and listen for the chirp and feel if the bearing has any sticking points.

 

OO ok, I think i'll try that. I'm not driving it right now, or at least until i figure out what that noise is.

 

Well you could try to disconnect the cog belt and see if the chirp is still there. This would narrow it down to being the head unit or the jackshaft pulley. That's what I did and found that the chirping was coming from the jack shaft area, it does it from time to time but hasn't gotten worse and actually seems like it's doing it less if at all. It's been a year so if something was going to go bad, I would of expected it to happen by now so I don't worry about it.

 

If I remove the cog belt, would i be able to run my car? I would assume you couldn't turn on your car cuz it was set to run off the supercharger.

 

your off boost tune doesnt change.

 

So, just to be certain, if i take off the cog belt, i can turn the car on as long as the serpentine belt is attached? I just want to be certain.

 

For sure...I do it all the time when I want my car to be quieter...

 

http://www.youtube.com/watch?v=s89Mo7PsEu0
http://www.youtube.com/watch?v=y93U_c7FfBY
http://www.youtube.com/watch?v=BDdplQKhHd4

My videos of a bad bearing causing the impeller to rub the volute.

 

http://www.youtube.com/watch?v=Lu2iW6dzuXI

I am not sure how to post this, but this is the noise i'm experiencing, sounds like a chirp.

 

Did you remove the cog belt yet and see if the problem is eliminated? It sounds like something in your jackshaft bearing area (the chriping sound is coming from something rotating at a much slower speed than the supercharger is spinning at). Does not sound like the supercharger but only one way to confirm this......

 

I will try that later this week. I wanted to try that but wasn't able to this weekend. Which is the jackshaft area?

 

Your cog belt connects the supercharger head unit to the jack shaft. It takes 30 seconds to take this belt out.

 

Sorry, i forgot to mention, i live in an apartment, that's why i have to wait until i either go to my friends house or my parents house to do stuff. I'm gonna unhook the cog belt next. Thanks for the direction.

 

Ok, so something happened that's gonna make it hard to diagnose. The noise is gone sponatenously. I've driving it all week waiting for the noise and it just never came back. I'm gonna say, maybe the noise was due to not driving the car enough. But thanks everyone for your help. I really appreciate it. THanks.