2019 GT hissing sound

[Cheezzy]

So I installed a JLT passenger side catch can drove my car around got back popped the hood and all could hear was this constant hissing sound. I cant hear this sound while driving or when the hood is closed. I swapped the catch can out and put the factory hose back in and it still has a constant hissing sound around the front of the intake manifold area. I'm no real mechanic but i don't remember my car having this sound I only have 4k miles on the car. Then I again I didn't really pay attention till now.

I know when the car shuts off it sounds like it releases all the air in the system when it shuts off so I don't know.

I read about the AC system causing a similar sound and the sound I'm hearing is there with AC on or off.

I do have a video.

Like I said that sound is there with catch can and factory hose. I can't feel anything leaking and I don't see anything either.

Also the sound was definitely louder after driving around for an hour versus when I just let it warm up in the garage.

Any ideas or should i just take it over to the dealership?

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[Kermitz]

Is it possible that this hissing sound has always been there and you're only hearing it now because you're looking under the hood?
My 19 has a similar if not that same hiss at times, it runs fine.

 

[Cheezzy]

Is it possible that this hissing sound has always been there and you're only hearing it now because you're looking under the hood?
My 19 has that same hiss at times, it runs fine.

Yes that's what I'm getting at the sound could of always been there and i just never noticed when I've had the hood open which has been like a couple times mainly when i did my oil change and checked my fluids. This is the first time i've noticed the sound and i'm trying to find out if anyone else has this same type of sound and if its normal. As i said above it doesn't matter if the catch can is on or the factory hose same sound im guessing its got nothing to do with those items at all anymore.

My car runs fine and i've had no problems.

I will say at first i did contact JLT and said something to them about it and they were ready to send me a replacement. I told them today it wasn't their cans fault but i liked how stand up they were about it.

 

[grundlescrape]

Apologies for necro'ing the thread, but I made an account just to let you know I have this exact same thing going on. Same car, too -- PP1 and model year at least (also based out of Ohio!).

Also running a JLT catch can. I checked for vacuum leaks with a smoke tool and saw nothing weird going on. Worth nothing my buddy with a GT350 has this noise as well, so does my neighbor with a 2018 GT California Edition, noise is coming from near the intake. My thinking is it's some kind of compressor or something for accessories maybe. Does yours make a blowoff-valve kind of noise when you shut the engine off? I can only hear these noises with the hood up and RPM doesn't seem to make a difference.

Consensus is that it's there by design and not hurting anything. Do you have the vacuum gauge on the dash?

 

[Cheezzy]

Apologies for necro'ing the thread, but I made an account just to let you know I have this exact same thing going on. Same car, too -- PP1 and model year at least (also based out of Ohio!).

Also running a JLT catch can. I checked for vacuum leaks with a smoke tool and saw nothing weird going on. Worth nothing my buddy with a GT350 has this noise as well, so does my neighbor with a 2018 GT California Edition, noise is coming from near the intake. My thinking is it's some kind of compressor or something for accessories maybe. Does yours make a blowoff-valve kind of noise when you shut the engine off? I can only hear these noises with the hood up and RPM doesn't seem to make a difference.

Consensus is that it's there by design and not hurting anything. Do you have the vacuum gauge on the dash?

It does make that type of noise when it shuts off. I do have a vacuum guage on the dash. I just decided that it was normal after reading around and found some similar stuff on other peoples cars. I figured when I take my car in to get service I'd ask them about it and see what they say.

 

[njweatherman]

Guys,
I have a 2020 mustang gt, California edition, automatic, stock, and I have the same hissing noise from the engine bay. It sounds like an air leak. 3500 miles.

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