[pisters]

Hello friends, I have a strange noise that is starting to bother me.

It sounds towards the hood of the car, when I stop at a traffic light sometimes I hear a noise like " TUC" quite noticeable.

Also sometimes when I put the gear in P then release the brake and after a few seconds I hear the noise, but most of the time it sounds when I'm in D gear stopped at a traffic light.

Even a two days ago, when I turned off the engine after few seconds I heard the noise again.


Is it something from the engine, gearbox? I doubt a little that it is the engine because even after being turned off it sometimes makes the noise.

My car is a Camaro 2021 2.0 Turbo A8, 19k miles, stock. Super well maintained, just one owner. No crashes or anything. I take very good care of it

[pisters]

On two occasions while waiting at traffic lights I felt something on the brake pedal.

Before the noise was rarely heard, now it is heard every day and more frequently.

Also the car is used for 80% highway and 20% city driving. So it doesn't have much wear.

[Kamero6]

Is it a metallic noise? Like someone hitting metal with a hammer?
Could be the exhaust expanding and contracting. All cars do it.

[pisters]

Originally Posted by Kamero6

Is it a metallic noise? Like someone hitting metal with a hammer?
Could be the exhaust expanding and contracting. All cars do it.

No man, its like somebody with a fist hitting your dashboard, its one time noise sometimes. You can hear the noise behind the dashboard, so it is most likely coming from under the hood.

[Yang N’ Bang]

Try and get a video if possible, will do wonders for all of us to give a guess.

[len125]

i had a rattle in the dash for about a month...i just kept playing with the heater/AC/defroster/ and it went away...

[Kamero6]

If it happens with the engine off, it is related to metal expansion / contraction most likely. Does it happen more often with the car super hot, after driving hard or when its been driven slow?
AC actuators? Try driving with AC / climate off and see what happens. At this stage testing is the only thing you can do

[pisters]

Originally Posted by Kamero6

If it happens with the engine off, it is related to metal expansion / contraction most likely. Does it happen more often with the car super hot, after driving hard or when its been driven slow?
AC actuators? Try driving with AC / climate off and see what happens. At this stage testing is the only thing you can do

The noise is rarely heard, it is not easy to know when it will be heard. I have already clarified that it is not the exhaust sound, this noise is much louder and it only makes it once.

Generally when the car is warm after an hour of driving (and driving normal since I'm in the city) you hear the noise behind the dashboard, it's like someone makes a fist bump to the dashboard "TUC".

The strange thing is that the noise is only made when the car is stoped, not in motion.

I already tested it driving without the AC or climate control but it still makes the noise.

It ALMOST ALWAYS does it after braking, or when I hold down the brake pedal at a traffic light, or when I put it in P and then release the brake (it has done it twice already).

I think it has something to do with the brake as I have felt a slight tapping on the brake pedal on two occasions.

[ctrlz]

Without much information, my guess is that your brake vacuum booster is making the noise. Possibly related to a leaky check valve.
I think the sound you hear may be the diaphragm moving quickly.