Screeching/grinding sound when applying sudden pressure to throttle
 

Hello 86fam,

I'm wondering if anyone can help me with this problem. I get a faint screeching/grinding sound when sudden pressure is applied to the throttle. The sound only happens for a split second and often happens around 2k-4k from 2nd - 6th gear. I have a 2017 BRZ M/T

I can't seem to find any open forum regards to this. Any help will be greatly appreciated

go for simple first, check belt tension.

your exhaust must be pretty quiet

Hi PaoloJR and welcome to our forum. -:clap:

What power mods do you have on your car, if any?

How many miles on your car?

How long has it been making this sound?

Where does the sound seem to be coming from?

Does it make the sound when the car is standing still?


Come back.


humfrz

Hey! thank you!

only mod I have is a borla catback
i have about 16k miles on it
ive been hearing it for quite sometime now, maybe back in June?
the noise seems like its coming from the footwell area and no it does not make the sound when the car is on idle

OK, does the car make that sound when it is in neutral and you just rev the engine?

If so, I suggest you raise the hood, stick your head in the engine compartment, have someone rev it up and see (hear) if you can isolate the sound.

Did you check the belt tension as suggested?


humfrz

it is pretty much a new car with no significant mods and OP hasn't told us of any mechanical problems so I'm betting he is hearing nothing important especially if it is faint. Plenty of people hear weird noises with this platform all the time and unless it actually affects how the car drives it doesn't mean much.. I'd say just have someone who is familiar with the twins or maybe someone from the dealership take a drive and have them check if they notice anything weird..

Exhaust leak.

I think I've heard the sound you speak of. Usually when cruising at a steady speed and gently giving it a bit of gas, like cruise in 6th at 2k and gently give it gas for a gentle overtake. I've also heard it as I tip in the throttle on upshifts as the clutch makes contact, which makes me think it may be some gear lash rattling as the drive line loads up.

I've noticed that when it does it, the gentler the accel, the more it does the noise, nailing the gas harder shortens the duration, until nailing it instantly just doesn't produce it at all.

This describes what mine does to a T.

exactly what i am experiencing.

I had a mechanic at a local dealership listen as I drove it and he said it doesn't sound something normal.. I am going in next week so they can take a look and hopefully find whats wrong with it :(

did you ever got this checked out?

While it's making the noise, try just barely tapping the clutch pedal. Sounds crazy but the return spring inside my master cylinder would occasionally vibrate with an awful rattle right around 3500 RPM. Hasn't done it for a couple years.

I've mentioned this in other threads and it seems like no one else has had it.

Nope; I chalked it up to drivetrain lash and left it at that, since it doesn't do it ALL the time.