Escaping/ Compressed Air Noise

[DaBoBo21]

Originally Posted by Tcoat

Ya just trying to get a time line on the different symptoms. It is getting confusing at this point as to exactly what happened when.

Here's my timeline:

MAR17 - Catback installed/ doubled checked for leaks
APR17 - Dealership installed refreshed TOB via TSB (never had issues to begin with) and replaced front-pipe due to heatshield rattle (we'll come back to this).
AUG17 - One morning, the car wouldn't go into reverse pulling out of garage (clutch fully depressed). Next morning, on cold start I begin hearing a rattle from the bell housing/ transmission area. Has happened every morning since. Goes away once the car is fully warm.
OCT-NOV17 - Went to the dealership because my clutch pedal was making a rubber on rubber sound, I have since then fixed this with some lucasoil grease (great stuff). Also, I started to hear that compressed air/ BOV noise I'm talking about. They checked for exhaust leaks and found nothing and could confirm the noise, but told me to deal with it and that the car is meant to make noises and to wait for something to break because it's covered.
Last Week - After cold start, car wouldn't go into first gear. Had to take off in second gear and then everything was fine after that.
Present Day - Did what @humfrz suggested lol. Scared the hell out of myself, so I didn't finish the process. The rattling on cold starts is more pronounced now having done so and I can hear popping at random times if I'm going slow enough when I depress the clutch.

I have an appointment to the dealership for next Thursday, but I may just go tonight after work and see if they can hear me out this time.

Just to be clear, I know what sounds are normal for this car. I've driven too many to not. They're raw and meant to be noisy, but I know there's something going on here and it stems back to AUG17 when it wouldn't go into reverse.

[Tcoat]

Originally Posted by DaBoBo21

Here's my timeline:

MAR17 - Catback installed/ doubled checked for leaks
APR17 - Dealership installed refreshed TOB via TSB (never had issues to begin with) and replaced front-pipe due to heatshield rattle (we'll come back to this).
AUG17 - One morning, the car wouldn't go into reverse pulling out of garage (clutch fully depressed). Next morning, on cold start I begin hearing a rattle from the bell housing/ transmission area. Has happened every morning since. Goes away once the car is fully warm.
OCT-NOV17 - Went to the dealership because my clutch pedal was making a rubber on rubber sound, I have since then fixed this with some lucasoil grease (great stuff). Also, I started to hear that compressed air/ BOV noise I'm talking about. They checked for exhaust leaks and found nothing and could confirm the noise, but told me to deal with it and that the car is meant to make noises and to wait for something to break because it's covered.
Last Week - After cold start, car wouldn't go into first gear. Had to take off in second gear and then everything was fine after that.
Present Day - Did what @humfrz suggested lol. Scared the hell out of myself, so I didn't finish the process. The rattling on cold starts is more pronounced now having done so and I can hear popping at random times if I'm going slow enough when I depress the clutch.

I have an appointment to the dealership for next Thursday, but I may just go tonight after work and see if they can hear me out this time.

Just to be clear, I know what sounds are normal for this car. I've driven too many to not. They're raw and meant to be noisy, but I know there's something going on here and it stems back to AUG17 when it wouldn't go into reverse.

OK, so, even though Hum made light of the topic the highlighted all point to TOB. It doesn't make sense since it was changed but those are some of the symptoms I had. Your comments about the car being "slugish" could also be a symptom.There are of course other things it could be but those all match.


The BOV noise sure sounds like a vacuum or exhaust issue.
Perhaps something was loosened or removed when the did the other work. You positive it is an air sound? Could it be the TOB lightly brushing against the clutch fingers?

[DaBoBo21]

Originally Posted by Tcoat

OK, so, even though Hum made light of the topic the highlighted all point to TOB. It doesn't make sense since it was changed but those are some of the symptoms I had. Your comments about the car being "slugish" could also be a symptom.There are of course other things it could be but those all match.


The BOV noise sure sounds like a vacuum or exhaust issue.
Perhaps something was loosened or removed when the did the other work. You positive it is an air sound? Could it be the TOB lightly brushing against the clutch fingers?

I think it could very well be the TOB scraping against the fingers, but what would explain me hearing the compressed air in motion, but not at idle?

[Tcoat]

Originally Posted by DaBoBo21

I think it could very well be the TOB scraping against the fingers, but what would explain me hearing the compressed air in motion, but not at idle?

Ya it really shouldn't make the noise when the clutch is engaged. Probably back to a vacuum line someplace. Vacuum leaks can be a royal pain to track down.

[DaBoBo21]

Originally Posted by Tcoat

Ya it really shouldn't make the noise when the clutch is engaged. Probably back to a vacuum line someplace. Vacuum leaks can be a royal pain to track down.

Yeah, the rattle I have goes away when I fully push the clutch and resumes once my foot comes off the pedal, and like I said is gone once it's fully warm. The rattle also stops when you put the shifter into a gear position w/o putting it all the way in gear (not using the clutch at all).

Yeah, I've literally checked all the vacuum lines I could find and nothing felt loose..

[Tcoat]

Originally Posted by DaBoBo21

Yeah, the rattle I have goes away when I fully push the clutch and resumes once my foot comes off the pedal, and like I said is gone once it's fully warm. The rattle also stops when you put the shifter into a gear position w/o putting it all the way in gear (not using the clutch at all).

Yeah, I've literally checked all the vacuum lines I could find and nothing felt loose..

Not sure how the shifter position would have an impact on the TOB so that is a mark against that being the issue.


OK if none are loose you need to start tracing them back and looking for damage through the length. I do not envy you that task.

[DaBoBo21]

Originally Posted by Tcoat

Not sure how the shifter position would have an impact on the TOB so that is a mark against that being the issue.


OK if none are loose you need to start tracing them back and looking for damage through the length. I do not envy you that task.

Input shaft bearing? Pilot bearing? I honestly think my TOB is fine. It's never been an issue for me. The car only has 13,700 miles on it and I never abuse the clutch even when I'm driving spiritedly..

Yeah, not looking forward to it, man. lol

[Tcoat]

Originally Posted by DaBoBo21

Input shaft bearing? Pilot bearing? I honestly think my TOB is fine. It's never been an issue for me. The car only has 13,700 miles on it and I never abuse the clutch even when I'm driving spiritedly..

Yeah, not looking forward to it, man. lol

No the bearings shouldn't be impacted unless the shift lever is actually putting pressure on the gear changer. This whole thing is a bit baffling! Drive over here so I can hear it would you?

[DaBoBo21]

Originally Posted by Tcoat

No the bearings shouldn't be impacted unless the shift lever is actually putting pressure on the gear changer. This whole thing is a bit baffling! Drive over here so I can hear it would you?

I wish I could lol. Well I believe when I put it into gear position I am putting pressure on the gear changer. I think that's why the noise stops, and then when I relieve the pressure it begins again.

[Ultramaroon]

More mysteries. :|

Staying tuned and hoping the best. Waiting for something to break is a bullshit response.

"Wait until you are stranded on the side of the road at the worst possible time. Meanwhile, drive knowing it could take a dump anytime."

[DaBoBo21]

Originally Posted by Ultramaroon

More mysteries. :|

Staying tuned and hoping the best. Waiting for something to break is a bullshit response.

"Wait until you are stranded on the side of the road at the worst possible time. Meanwhile, drive knowing it could take a dump anytime."

Pretty much, man. It's been very irritating and stressful to say the least. They spent two hours trying to figure out my clutch pedal noise and lubed up everything but the area that was causing the noise and it took me about 10 minutes to find it and grease it last Sunday.

[orz]

Any updates on what's causing the sound?

[ChesterV]

Was this ever fixed?

[Blighty]

Originally Posted by arren123

I hear it in my 2017 BRZ MT. It's totally stock.
I can only hear the noise when loading the engine, not at steady state.

I had my rear seats down and it sounds like it coming from the rear of the car, so I was thinking it was from the exhaust.

Try driving with your rear seats down and see if the noise is more pronounced.

I get this exact noise in my 2022 BRZ.

Only started hearing it with the back seats down, and its almost like its after a short load up time it starts making a light air escaping noise, then when I back off the throttle it takes about 1 or 2 seconds and the hiss fades out. Back on the throttle and after a second or so it fades back in.

Wondering if its the secondary cat or something that is filling or saturating and then its either leaking or vibrating something to sound like an air leak or something.

Did you ever have a problem with it over time?