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Discussion Starter #1
Hi everyone,

I have an 06 Exige with an MP62 supercharger (BWR). I am hearing a constant chirping noise when the car is in gear but goes away when in neutral. You can take a listen here:

Does anyone know where this could be
coming from and how I can get rid of it? Just fyi I had the supercharger rebuilt so it’s probably not the coupler, and it was making the same sound before the supercharger was rebuilt.

Thanks in advance for your input.

-Justin-
 

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Is this when you are driving or only when you step on the clutch pedal??
 

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Discussion Starter #3
It’s only when I am in gear regardless of the clutch or gas. It almost sounds like it’s coming from the belt but it’s just a wild guess.
 

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I cannot hear anything odd in the video. I assume you get on full-throttle in the middle of the video? It presents the usual SC whine. Who did your MP62 rebuild?

"only when I am in gear regardless of the clutch or gas" is a very odd mixture. Clutch-in, there is no torque on the drive train, so rules out engine movement. Gear-engaged versus gear-not-engaged, both with clutch-in, sounds like something in the clutch or gearbox and "chirping" does not sound like a gearbox thing (no grinding) so I guess you have something nasty going on in the clutch. My ACT clutches lose chunks of friction material with abuse, and a badly-located bit of friction material may cause a chirp when the output shaft is engaged (spinning the friction plate with a bit of friction material in the pressure-plate space). Stabbing in the dark, sorry...

Put it up on jack-stands, start, and put it in 1st or 2nd and idle. See if you hear anything.

I would personally mostly ignore it, drive it as hard as I can, with earplugs, and hope it goes away (vaporize that bit of whatever). :)

Admittedly I get through a gearbox every two years or so...
 

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Discussion Starter #5
I cannot hear anything odd in the video. I assume you get on full-throttle in the middle of the video? It presents the usual SC whine. Who did your MP62 rebuild?

"only when I am in gear regardless of the clutch or gas" is a very odd mixture. Clutch-in, there is no torque on the drive train, so rules out engine movement. Gear-engaged versus gear-not-engaged, both with clutch-in, sounds like something in the clutch or gearbox and "chirping" does not sound like a gearbox thing (no grinding) so I guess you have something nasty going on in the clutch. My ACT clutches lose chunks of friction material with abuse, and a badly-located bit of friction material may cause a chirp when the output shaft is engaged (spinning the friction plate with a bit of friction material in the pressure-plate space). Stabbing in the dark, sorry...

Put it up on jack-stands, start, and put it in 1st or 2nd and idle. See if you hear anything.

I would personally mostly ignore it, drive it as hard as I can, with earplugs, and hope it goes away (vaporize that bit of whatever). :)

Admittedly I get through a gearbox every two years or so...
Thanks... if you listen carefully it’s the sound of a belt making a high pitched noise before and after the supercharger whine.

I’d ignore it if it didn’t lead to any bigger problems but I am trying to take preventive measures. I also track my car so I don’t baby it either. :)
 

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How's the belt wear look? Are the sides still fresh looking? Almost like the tension pulley not quite a engine noise that I hear. Or alt? If you put a flat plane against pulleys do they all line up?
 
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Discussion Starter #7
How's the belt wear look? Are the sides still fresh looking? Almost like the tension pulley not quite a engine noise that I hear. Or alt? If you put a flat plane against pulleys do they all line up?
They still look fresh. Here’s a better video with the sound:
 

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Maybe get one of those cheap stethoscopes from HF and see if its coming from idler or alt.
 
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Discussion Starter #9
Maybe get one of those cheap stethoscopes from HF and see if its coming from idler or alt.
You may be on to something. My mechanic installed a brand new alternator from Celica GTS yesterday but told me for some reason the alternator had been installed in a location that is different from stock. I am going to investigate this. Thanks!
 

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Yeah that would be a red flag to me for starters. Q&A is a big part of PD and when circumstances change and problems arise my ears always perk up.
 

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I'd second the check on pulley alignment. I've seen mp62 pulleys with the wrong offset upwards of 6mm.

Wetting the belt with some detergent and water would temporarily stop any belt squeal.

Sent from my Pixel 4 using Tapatalk
 

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Discussion Starter #12 (Edited)
Just confirmed that it's coming from the belt. I confirmed this by spraying water slightly on the belt where the supercharger pulley is located which silences the squeal/squeak momentarily but when it dries off the noise comes right back in a minute. Given the foregoing:

1. Should I put on a new belt to see if the noise goes away or try tightening the pulleys or look at the alignment?
2. Could a bad belt cause a slip at 4000-5000 rpm which feels like hesitation during a pull? after 5000 rpm the car pulls really strong and I am wondering if it's a related issue.
3. Or could this be not that simple and also be caused by the tensioner pulley or other pulleys? I think the spray test rules these out but just wanted to see if I am overly sampling this issue.

Thanks again gentlemen for the great advice.
 

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yes,yes,yes

Check alignment of all pulleys with a flat plane, make sure pulleys are tight, hand spin tensioner and check for movement and or noise if in doubt replace. How old is your belt? There is more than one length available, does your tensioner still have room to tension your belt? Wondering if it might be wrong belt and a tad long? What is condition of the belt?
 

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I would change that belt and as @Catsailr27 recommends, check that the tensioner pulley bearing (it is really close to the exhaust header and does not last forever).

Have you had the belt off? It takes a pretty compact socket and breaker-bar to compress the tensioner damper (it will not move fast under compression) because of the tight-space. Note the belt routing with a pic (I always think it is obvious how it goes back on until I have to put it back on, haha). It is worth marking the body of the damper with a sharpie 1) before removing the belt, 2) fully compressed, 3) fully decompressed and measure the travel when the belt is off so you can assess the belt-length. It is not so simple to get the correct belt size.
 
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