I have an r53 and the past few days have been rough on my car. For some reason it has been making a chirping sound coming from the driver's side whenever I go past 25% throttle. It also does it when under some load. The car also surges if I hold it at 4k. Does anyone know what this could be? Is it the bypass valve or the throttle body?

 

Got a vid of sound?

tb or bv do not chirp. Or a should say I can’t see those chirping.

could be a pulley

 

I am certainly no expert but I had and heard a similar sound you describe on my 04 MCS. It finally threw the belt. The idler pulley/bearing failed.
Possibility?

 

Here is a video of the car going uphill on the highway. Cruise control was on and set to 65mph. The noise also comes when rev matching as well. I rebuilt the engine at 90K. It has a new water pump, supercharger oil, idle pulley, harmonic balancer, belt, and all new gaskets.

 

Is the ac going? Guess: blower motor

Do you hear the noise from the engine bay? I’m thinking have someone rev while you record in the engine bay?

less road noise…

 

The ac is going but the noise is there even when I turn it off. I can try to get a video of the engine bay. The other issue is if i roll onto the throttle when rev matching the noise is not there. But if I quickly heal toe the pedal the noise comes back, the engine hesitates to rev and just end up backfiring.

 

Update. She finally threw a code. P0122 and P0222. I assume that this means I need to get a new throttle body

 

New update. The noise was not coming from the throttle body. the chirping was my supercharger pulley. It blew off while we were doing some tests. I switched to a 17% Alta pulley and now it is running smooth.

 

I would've said a pulley, and my best guess would be the idler pulley. Thanks for adding the solution to your thread, this is what makes a forum valuable!