Help me find the noise

[Torinate]

ANY Verdict?

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[smann]

Nope LOL!! I'm going to shop tomorrow to get my WOT box installed.
They're going to try finding it.

My car is still very embarrassing shutting off.
I never shut it off when there's other people around !! LOL

 

[sigintel]

This is 2 minutes tops:
There is a vacuum line that runs to brake booster. It has a small black round check valve on the end of the hose. You can wiggle the check valve out of the booster housing.
You will end up with a loose hose end that still has the check valve attached.
Hold you finger over open end of check valve.
Turn off motor.
Any change?

If no.
Remove check valve and hold ooen end near ear.
Shut down again and see if you can hear sound also in hose end.

There are a couple check valves connected to the intake vacuum:
Brake booster
Evap
??others

What likely happen is the person doing smoke test used shop air at 60-120 psi and blew a hole/tore a seat in a diaphragm or check valve.
Smoke test should only be done at 14-28psi max as thats max for many check and diaphragms.

Evap is on ?back of intake against firewall?

 

[Mustang_Lou]

^ that's the best possibility I've heard so far.

 

[smann]

Thanks everyone for the help!

Finally got it figured out.. Its the back of IM close to the firewall.
I took it to a shop they used a mechanics stethoscope and pinpointed the sound.

When the car shuts off, theirs still air being released from the little tear/rip so it sounds like a balloon.

I think the sound has been echoing off because its right at the back of the engine/IM.

Thanks everyone for the suggestions!! Going to put on an '18 mani and see if it fixes the problem. My mechanic shop assured it would.

sigintel, Today at 6:11 PM

This is 2 minutes tops:
There is a vacuum line that runs to brake booster. It has a small black round check valve on the end of the hose. You can wiggle the check valve out of the booster housing.
You will end up with a loose hose end that still has the check valve attached.
Hold you finger over open end of check valve.
Turn off motor.
Any change?

If no.
Remove check valve and hold ooen end near ear.
Shut down again and see if you can hear sound also in hose end.

There are a couple check valves connected to the intake vacuum:
Brake booster
Evap
??others

What likely happen is the person doing smoke test used shop air at 60-120 psi and blew a hole/tore a seat in a diaphragm or check valve.
Smoke test should only be done at 14-28psi max as thats max for many check and diaphragms.

Evap is on ?back of intake against firewall?

I think you got it spot on with the PSI of the smoke test. This immediately started happening after that


I guess it also makes sense now how my throttle response has been shittier, seeing slight knock and of course that sound.

 

[smann]

Update: New intake manifold made no difference to noise.. However it does pull harder up top LOL.
Throttle response back to normal, seeing maximum +1 knock on low throttle, pulls hard with NO knock and adds timing at wot.

Still am puzzled about this sound!!!

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