Mine does the same thing, if the clutch is engaged it doesn't rattle but if the car is in neutral it happens every time.
Clunking On ShutOff
Thread Starter
Instructor
Joined: Sep 2007
Posts: 186
Likes: 0
From: Lake Tahoe Nevada
Clunking On ShutOff
Hello everybody, I am new to the forum and this is my first post.
When I turn the key to shut the engine off On my 2003 Z06, there is a rattling/clunking as the engine shuts down. By the time the engine is completly off all clunking and rattling is gone. It happens most of the time when I shut the engine off but not always. I am unable to notice any consistency with this problem. It sounds to me to be an exaust component. Any ideas or similar problems would be a help.
Thanks
Zach
When I turn the key to shut the engine off On my 2003 Z06, there is a rattling/clunking as the engine shuts down. By the time the engine is completly off all clunking and rattling is gone. It happens most of the time when I shut the engine off but not always. I am unable to notice any consistency with this problem. It sounds to me to be an exaust component. Any ideas or similar problems would be a help.
Thanks
Zach
Instructor
Joined: May 2007
Posts: 111
Likes: 0
From: Barrie Ontario
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Zach
The noise you hearing is the spline joints that connect the different parts of the drive train together and the gears in the trans. Each spline joint has designed tolerances that allow them to slip fit together correctly. The clutch disk also has a splined joint. Some of the noise that your hearing is that disks spline joint.
When you shut the engine down, as the engine coast down to very low RPMs the cylinders start to oscillate against compression and cause those spline joints and gears to rotate from one side of the designed clearance to the other. The other spline joint connections are the trans to torque tube and torque tube to rear end. The gears in the trans have even more clearances and also oscillate and make lots of noise.
The transmission (MN6/MN12) gear clearances have even more clearance and contribute to the noise. That why pressing in the clutch helps eliminate it. The clutch disk no longer connects the drive train to the trans.
Long story short, it is indeed very normal and can be minimized by depressing the clutch prior to shutting down the engine.
BC
The noise you hearing is the spline joints that connect the different parts of the drive train together and the gears in the trans. Each spline joint has designed tolerances that allow them to slip fit together correctly. The clutch disk also has a splined joint. Some of the noise that your hearing is that disks spline joint.
When you shut the engine down, as the engine coast down to very low RPMs the cylinders start to oscillate against compression and cause those spline joints and gears to rotate from one side of the designed clearance to the other. The other spline joint connections are the trans to torque tube and torque tube to rear end. The gears in the trans have even more clearances and also oscillate and make lots of noise.
The transmission (MN6/MN12) gear clearances have even more clearance and contribute to the noise. That why pressing in the clutch helps eliminate it. The clutch disk no longer connects the drive train to the trans.
Long story short, it is indeed very normal and can be minimized by depressing the clutch prior to shutting down the engine.
BC
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
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
Burning Brakes
Joined: Jun 2007
Posts: 1,047
Likes: 69
From: Hanover MA.
Hello everybody, I am new to the forum and this is my first post.
When I turn the key to shut the engine off On my 2003 Z06, there is a rattling/clunking as the engine shuts down. By the time the engine is completly off all clunking and rattling is gone. It happens most of the time when I shut the engine off but not always. I am unable to notice any consistency with this problem. It sounds to me to be an exaust component. Any ideas or similar problems would be a help.
Thanks
Zach
When I turn the key to shut the engine off On my 2003 Z06, there is a rattling/clunking as the engine shuts down. By the time the engine is completly off all clunking and rattling is gone. It happens most of the time when I shut the engine off but not always. I am unable to notice any consistency with this problem. It sounds to me to be an exaust component. Any ideas or similar problems would be a help.
Thanks
Zach
