This is what it sounds like to me, and if so, completely normal.
Cold Start Engine Noise
Thread Starter
Safety Car
Joined: Jul 2012
Posts: 4,558
Likes: 285
From: Houston Texas
C5 COTM Coordinator
Cold Start Engine Noise
My 01Z 80k miles as of 2 days ago has been making a weird sound upon starting it on a cold start. The noise is nothing of the taping or knocking sort but kinda like a hissing or air sound coming from the serpentine belt area. After engine warms up a bit the sound goes away. All fluids are normal, no leaks, no trouble codes. The car operates flawlessly, what drives me crazy is that damn sound at the start! 
What is it? Just trying to play it on the safe side wouldn't want it to cost me more money down the road. Any idea guys?
What is it? Just trying to play it on the safe side wouldn't want it to cost me more money down the road. Any idea guys?
Last edited by Maxx_Z06; Mar 12, 2013 at 01:09 PM. Reason: added information
Race Director
Joined: May 2010
Posts: 16,574
Likes: 13
From: Winfield IN
Thread Starter
Safety Car
Joined: Jul 2012
Posts: 4,558
Likes: 285
From: Houston Texas
C5 COTM Coordinator
If it's completely normal why was it not doing it before and now is? I understand that it's just an emission and no code comes up because my car is tuned. However, I guess I'm pretty **** and would like to not hear that very time i turn it on cold lol.
Burning Brakes
Joined: Apr 2010
Posts: 1,073
Likes: 3
From: Asheville NC
I don't really know other than to take it completely out of the car or maybe try to find it's power source and disconnect it from there.
I for one have never heard or even payed attention to the noise that it makes even before I got the check engine light for it and I have had my Z06 for several years now.
I for one have never heard or even payed attention to the noise that it makes even before I got the check engine light for it and I have had my Z06 for several years now.
Thread Starter
Safety Car
Joined: Jul 2012
Posts: 4,558
Likes: 285
From: Houston Texas
C5 COTM Coordinator
Turned it on this afternoon after work and the sound is still there. It's not coming from below the drivers side headlight (air pump) but from the serpentine belt area. I'm going to swap out the belt this weekend see what happens from there.
Le Mans Master
Joined: Nov 2006
Posts: 7,215
Likes: 1
From: Orlando FL
good luck, how old is the belt?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Safety Car
Joined: Jul 2012
Posts: 4,558
Likes: 285
From: Houston Texas
C5 COTM Coordinator
The noise has mysteriously gone away. After some reading i thought it might be a bad bearing inside the alternator. I still have both belts on their way to put on just to replace the old ones. I'm not sure how old they are but better safe than sorry.
Drifting
Joined: Apr 2006
Posts: 1,936
Likes: 13
From: Redding California
Definitely a good idea to change the belts, and while they're off you can spin the alternator pulley, and anything else that will spin, and check for any bad bearings.
Safety Car
Joined: Sep 2011
Posts: 4,671
Likes: 1,245
From: Southern Ca
