Hello, Loud Hissing Noise Temporary
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Joined: Jun 2006
Posts: 1
Hello, Loud Hissing Noise Temporary
Hello,
I've already searched the forum for this and found nothing that is exactly the same or similar so I'm starting this new thread. I just bought a 2002 Camaro Z28 6 speed manual with 71,000 miles. This thing is awesome but I'm not too familiar at all with the engine yet. I've been dealing with Berettas for the last 5-6 years or so with 3100 / 3400 engines.
Anyways, recently my car has developed this loud hissing noise only on startup. The car's performance seems to always be perfect. There is no bogging or hesitation from the engine at any time. I just had the a/c tensioner pulley replaced. This is an intermittent issue at this point as well. All that I can really say is that there is this very loud hissing noise that stays the same pitch regardless of RPMs and it does not affect the performance. This noise never occurs when the engine is warm, only on cold startups.
After I start the car up it will start hissing loud right away and when I pop the hood it seems to be coming from the left side of the engine ( while outside the car looking under the hood near / behind the oil cap area.) After about 30 seconds to 1 minute 30 seconds the noise instantly goes away and there is nothing I notice after that. I can drive the car for hours, start and restart the engine and the noise does not recreate unless the engine is cold. I'm almost thinking at this point that it is something electrical because it instantly will go away. If I drive the car with the hissing noise it does not seem to affect how long it lasts after startup.
I'm curious if anyone has seen or heard of this problem before and if there is some good spots to start testing / looking at? I bought the GM Major Guard warranty on this car which is 2 years / 24,000 miles so I'm going to have this looked at next week if I can't figure this out. There is so many stipulations to this warranty that I would rather just repair this problem myself if inexpensive. The other thing is that this is an intermittent issue and if I take it in and it happens to not recreate itself they'll probably just say no fault found and charge me the deductible anyways. So if anyone has any ideas please share, otherwise Hello everyone, my name is Wade and this looks like a cool board that I'll be frequenting!.
I've already searched the forum for this and found nothing that is exactly the same or similar so I'm starting this new thread. I just bought a 2002 Camaro Z28 6 speed manual with 71,000 miles. This thing is awesome but I'm not too familiar at all with the engine yet. I've been dealing with Berettas for the last 5-6 years or so with 3100 / 3400 engines.
Anyways, recently my car has developed this loud hissing noise only on startup. The car's performance seems to always be perfect. There is no bogging or hesitation from the engine at any time. I just had the a/c tensioner pulley replaced. This is an intermittent issue at this point as well. All that I can really say is that there is this very loud hissing noise that stays the same pitch regardless of RPMs and it does not affect the performance. This noise never occurs when the engine is warm, only on cold startups.
After I start the car up it will start hissing loud right away and when I pop the hood it seems to be coming from the left side of the engine ( while outside the car looking under the hood near / behind the oil cap area.) After about 30 seconds to 1 minute 30 seconds the noise instantly goes away and there is nothing I notice after that. I can drive the car for hours, start and restart the engine and the noise does not recreate unless the engine is cold. I'm almost thinking at this point that it is something electrical because it instantly will go away. If I drive the car with the hissing noise it does not seem to affect how long it lasts after startup.
I'm curious if anyone has seen or heard of this problem before and if there is some good spots to start testing / looking at? I bought the GM Major Guard warranty on this car which is 2 years / 24,000 miles so I'm going to have this looked at next week if I can't figure this out. There is so many stipulations to this warranty that I would rather just repair this problem myself if inexpensive. The other thing is that this is an intermittent issue and if I take it in and it happens to not recreate itself they'll probably just say no fault found and charge me the deductible anyways. So if anyone has any ideas please share, otherwise Hello everyone, my name is Wade and this looks like a cool board that I'll be frequenting!.
Registered User
Joined: Mar 2002
Posts: 5
From: Plano, IL
Re: Hello, Loud Hissing Noise Temporary
Welcome! 
The noise you are hearing is your secondary air pump. It is normal to hear it at startup.
If it is really loud, and if your warranty covers it, you could replace it. I wouldnt really worry about it though, it is only an emissions device. It doesnt affect vehicle performance.
The noise you are hearing is your secondary air pump. It is normal to hear it at startup.
If it is really loud, and if your warranty covers it, you could replace it. I wouldnt really worry about it though, it is only an emissions device. It doesnt affect vehicle performance.
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Joined: Jul 1998
Posts: 6,247
From: Charlotte,MI USA
Re: Hello, Loud Hissing Noise Temporary
The A.I.R. pump on an LS1 f-body is electric and runs for a short while during cold startups to push fresh air into the exhaust so that the Catylitic converters will come up to temp faster.
It a perfectly normal noise.
It a perfectly normal noise.
Retired
Joined: Oct 1999
Posts: 3,166
From: Inside Uranus
Re: Hello, Loud Hissing Noise Temporary
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