supercharger

**rtorres422** · 03-19-2010

i have a 99 gtp and i replaced my coupler because my supercharger stopped whining, but still with the new coupler the supercharger doesn't whine. does anyone know why this might be happening?

**98GTPCALGARY** · 03-19-2010

when you had it apart did you try turning everything? to check for slack, and or bad bearings? or have you changed anything else, intake/exhaust?

**skidoojames151** · 03-19-2010

maybe the boost bypass valve is stuck not allowing boost, possible belt slippage?

**rmcardle3** · 03-19-2010

Hey Torres. Yea, Boost “By-Pass” valve is good to check first (expensive $211.00/dealer), but what about the vacuum lines that control the Boost “Solenoid” valve (which controls the Boost “By-Pass” valve). It's the little one (Boost “Solenoid” valve) next to the large one (Boost “By-Pass” valve) with the vacuum line (directly) connected to it. That vacuum line can cause all kinds of trouble, too. Good luck Torres.

**98GTPCALGARY** · 03-19-2010

does the DIC show bars "boost" on the gauge?

**Bio248** · 03-19-2010

'stopped whining' isnt a good enough description. are you making boost? how much boost? do you have a vacuum leak? did you forget a belt?

need more.

**blueguy** · 03-19-2010

I say the rubber "T" is rotted...20 to 1

**BwolfGT** · 03-19-2010

Originally Posted by bluegtp91

I say the rubber "T" is rotted...20 to 1

This

**GTPJOE90** · 03-19-2010

agreed

**rmcardle3** · 03-20-2010

Originally Posted by bluegtp91

I say the rubber "T" is rotted...20 to 1

Yes

**rtorres422** · 03-20-2010

how do i check if the boost bypass valve is working???

**98GTPCALGARY** · 03-20-2010

again, do you have no boost? or is it just not noisy anymore? does the boost gauge do anything?

**rtorres422** · 03-20-2010

it shows boost but not like it used to fill up before.

**rtorres422** · 03-20-2010

or also how do i know if it is belt slippage?

**98GTPCALGARY** · 03-20-2010

run the car, get somebody else to hit the gas a few times while you watch the belts, look for any pullies not tunning smooth, how is the tensioner arm and pullie?

**2000GTP** · 03-21-2010

check the bbv

**blueguy** · 03-22-2010

RUBBER T FITTINGS!!

I know it

**rmcardle3** · 03-22-2010

Originally Posted by rtorres422

how do i check if the boost bypass valve is working???

I agree with bluegtp91. I would say look for the presence of something that would MAKE IT fail. That would be the "rubber T fitting".

* Open the hood, looking into the engine compartment.

The vacuum line that starts under the SC nose cone, around the front of the SC, right there is a Rubber T Fitting.

The “Rubber T Fitting” goes on to directly connect to the "boost (vacuum) solenoid" (next to the larger boost bypass valve). That is why it is important, it can cause everything to go static, until vacuum control is restored. Look at the "Rubber T Fitting".