C5 experts please help!?
03-04-2017, 12:16 PM
#1
Heel & Toe
Thread Starter
C5 experts please help!?
Hello!
I am brand new to the forum, just bought my first Corvette ever yesterday.
I've been working on cars for a long time but Im not quite sure exactly what this noise is.
Around 1100-1300 rpms, there is a rattling noise that happens.
It ONLY happens in that rpm range and it only happens in 1st and 2nd gear.
You don't hear it at idle and as soon as you go over 1300 rpms it goes away.
Is this normal?
**** ADDED******
First post so Im still learning!! Thanks for all of your help.
The car is an automatic :/, 70k all stock and garage kept for 15 years.
****************
Thanks!
Super excited to be a part of the Corvette family.
I am brand new to the forum, just bought my first Corvette ever yesterday.
I've been working on cars for a long time but Im not quite sure exactly what this noise is.
Around 1100-1300 rpms, there is a rattling noise that happens.
It ONLY happens in that rpm range and it only happens in 1st and 2nd gear.
You don't hear it at idle and as soon as you go over 1300 rpms it goes away.
Is this normal?
**** ADDED******
First post so Im still learning!! Thanks for all of your help.
The car is an automatic :/, 70k all stock and garage kept for 15 years.
****************
Thanks!
Super excited to be a part of the Corvette family.
Last edited by txagg14; 03-04-2017 at 08:12 PM.
03-04-2017, 12:38 PM
#2
Race Director
Member Since: Jul 2007
Location: Arlington Hts, IL
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St. Jude Donor '13-'14-'15-'16-'17-'18-'19-'20-'21-'22-'23-'24
Welcome Aggie!
The first question would be location. Where does the sound appear to be coming from? Under the hood, drivetrain?? Since you mentioned 1st gear, 2nd gear we can assume it's a 6 speed?
The first question would be location. Where does the sound appear to be coming from? Under the hood, drivetrain?? Since you mentioned 1st gear, 2nd gear we can assume it's a 6 speed?
The following users liked this post:
txagg14 (03-04-2017)
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03-04-2017, 01:17 PM
#4
Le Mans Master
Further; exhaust hangers are known to jingle, more commonly the spring assembly. Could also be the "H pipe jingle"; a noise caused by the H pipe design.
You need to narrow down where it's coming from.
You need to narrow down where it's coming from.
03-04-2017, 01:24 PM
#5
Instructor
03-04-2017, 03:19 PM
#6
Does it almost sound like marbles or nails in a tin container being shaken around? My 2000 makes that same sound at nearly identical RPMs to what you described (mine is around 1,500-2,200 that I notice the sound). Mine is an auto, though.
For what it's worth, my 1992 Chevy Caprice with a 305 V-8, RWD and auto trans. made the exact same sound in the same rpm range as the Corvette. The Caprice never had an issue until 200,000+ miles. The Corvette has no "check engine light" and no codes are generating...meaning it's annoying, but I doubt it's anything to worry about. I just pretend it's not there like I did with the Caprice.
For what it's worth, my 1992 Chevy Caprice with a 305 V-8, RWD and auto trans. made the exact same sound in the same rpm range as the Corvette. The Caprice never had an issue until 200,000+ miles. The Corvette has no "check engine light" and no codes are generating...meaning it's annoying, but I doubt it's anything to worry about. I just pretend it's not there like I did with the Caprice.
03-04-2017, 03:24 PM
#7
1/4 mile/AutoX
if you push on the clutch does it go away then ? does it do it in neutral ??
Congrats on the Vette and welcome to the forum !!!! nice color !!!!
Congrats on the Vette and welcome to the forum !!!! nice color !!!!
03-04-2017, 07:20 PM
#8
Heel & Toe
Thread Starter
Does it almost sound like marbles or nails in a tin container being shaken around? My 2000 makes that same sound at nearly identical RPMs to what you described (mine is around 1,500-2,200 that I notice the sound). Mine is an auto, though.
For what it's worth, my 1992 Chevy Caprice with a 305 V-8, RWD and auto trans. made the exact same sound in the same rpm range as the Corvette. The Caprice never had an issue until 200,000+ miles. The Corvette has no "check engine light" and no codes are generating...meaning it's annoying, but I doubt it's anything to worry about. I just pretend it's not there like I did with the Caprice.
For what it's worth, my 1992 Chevy Caprice with a 305 V-8, RWD and auto trans. made the exact same sound in the same rpm range as the Corvette. The Caprice never had an issue until 200,000+ miles. The Corvette has no "check engine light" and no codes are generating...meaning it's annoying, but I doubt it's anything to worry about. I just pretend it's not there like I did with the Caprice.
That is exactly what it sounds like. Infact, I almost titled my post "Marbles in my exhaust" I really think the sound is coming from somewhere in the middle of the vehicle. I do not have anyone around me right now to push on the gas while I listen outside of the driver seat.
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rams drop, the sound is there again.
03-04-2017, 07:21 PM
#9
Heel & Toe
Thread Starter
I should have mentioned, the car is unfortunately automatic, but when the transmission shifts and rpms drop the noise comes back in that exact rpm range.
03-04-2017, 07:22 PM
#10
Heel & Toe
Thread Starter
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rpms drop, the sound is there again.
The H pipe jingle would make sense... I guess I'm just a paranoid new vette owner wanting to treat it like the royalty it is haha
03-04-2017, 07:23 PM
#11
Heel & Toe
Thread Starter
I really think the sound is coming from somewhere in the middle of the vehicle. I do not have anyone around me right now to push on the gas while I listen outside of the driver seat.
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rams drop, the sound is there again.
I will check the heat shield for sure. Thanks for the suggestion.
03-04-2017, 07:24 PM
#12
Heel & Toe
Thread Starter
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rpms drop, the sound is there again.
You have all been so helpful, I really appreciate it.
03-04-2017, 07:30 PM
#14
Melting Slicks
Member Since: Nov 2008
Location: Edmonton Alberta, Canada
Posts: 3,146
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Sounds like your catalytic converter is falling apart, fragments of ceramic rattling around in the unit. Take a rubber hammer and give the cats a tap or two and if it rattles you have your culprit. Or take to reputable muffler shop. You really don't give us much to work with eg mileage etc. Good luck.
LOL, luffy beat me to it...
LOL, luffy beat me to it...
Last edited by El original; 03-04-2017 at 07:30 PM.
03-04-2017, 07:32 PM
#15
Heel & Toe
Thread Starter
Sounds like your catalytic converter is falling apart, fragments of ceramic rattling around in the unit. Take a rubber hammer and give the cats a tap or two and if it rattles you have your culprit. Or take to reputable muffler shop. You really don't give us much to work with eg mileage etc. Good luck.
70k. all stock... garage kept for 15 years.
Been in Texas its whole life in relatively high humidity but not close to any saltwater (for rust sake)
I appreciate the info.
I'll get up under there and find out.
03-04-2017, 08:09 PM
#16
Team Owner
Member Since: Sep 2002
Location: Bonita Springs, Florida
Posts: 21,886
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If you have a 6 speed manual trans then yes that sound is normal. According to GM it's due to gear rattle as covered under GM Document ID# 1858665:
Subject: Info - Manual Transmission Operating Characteristics #03-07-29-004C - (08/28/2006)
Models: 2007 and Prior Passenger Cars and Light Duty Trucks (Including Saturn)
2007 and Prior Chevrolet and GMC Medium Duty Trucks with Manual Transmission
Important: Even though this bulletin attempts to cover operating characteristics of manual transmissions, it cannot be all inclusive. Be sure to compare any questionable concerns to a similar vehicle and if possible, with similar mileage. Even though many of the conditions are described as characteristics and may not be durability issues, GM may attempt to improve specific issues for customer satisfaction.
The purpose of this bulletin is to assist in identifying characteristics of manual transmissions that repair attempts will not change. The following are explanations and examples of conditions that will generally occur in all manual transmissions. All noises will vary between transmissions due to build variation, type of transmission (usually the more heavy duty, the more noise), type of flywheel and clutch, level of insulation, etc.
Basic Information
Many transmission noises are created by the firing pulses of the engine. Each firing pulse creates a sudden change in angular acceleration at the crankshaft. These changes in speed can be reduced with clutch damper springs and dual mass flywheels. However, some speed variation will make it through to the transmission. This can create noise as the various gears will accel and decel against each other because of required clearances.
Gear Rattle
Rattling or grinding (not to be confused with a missed shift type of grinding, also described as a combustion knock type of noise) type noises usually occur while operating the engine at low RPMs (lugging the engine). This can occur while accelerating from a stop (for example, a Corvette) or while operating at low RPMs while under a load (for example, Kodiak in a lower gear and at low engine speed). Vehicles equipped with a dual-mass flywheel (for example, a 3500 HD Sierra with the 6-speed manual and Duramax®) will have reduced noise levels as compared to vehicles without (for example, a 4500 Kodiak with the 6-speed manual and Duramax®). However, dual-mass flywheels do not eliminate all noise.
Neutral Rattle
There are often concerns of rattle while idling in neutral with the clutch engaged. This is related to the changes in angular acceleration described earlier. This is a light rattle, and once again, vehicles with dual mass flywheels will have reduced noise. If the engine is shut off while idling in neutral with the clutch engaged, the sudden stop of the engine will create a rapid change in angular acceleration that even dual mass flywheels can not compensate. Because of the mass of all the components, this will create a noise. This type of noise should not be heard if the clutch is released (pedal pushed to the floor).
Backlash
Backlash noise is created when changing engine or driveline loading. This can occur when accelerating from a stop, coming to a stop, or applying and releasing the throttle (loading and unloading the driveline). This will vary based on vehicle type, build variations, driver input, vehicle loading, etc. and is created from the necessary clearance between all of the mating gears in the transmission, axle(s) and transfer case (if equipped).
Shift Effort
Shift effort will vary among different style transmissions and synchronizer designs. Usually the more heavy duty the transmission, the higher the shift effort because of the increased mass of the components. Shift effort can also be higher in cold weather because the fluid will be thicker. Medium duty transmissions will not shift as quickly as a Corvette transmission. To reduce shift effort, do not attempt to rush the shift - allow the synchronizers to work as designed. Shifting harder will only increase the chance of rushing past the synchronizer leading to grinding while shifting.
Non-Synchronized Gears
Some light duty truck transmissions in 1st gear (creeper-gear) and reverse gears in various transmissions, along with all gears in some medium duty transmissions, may be non-synchronized. This means there is not a mechanism to match input and output shaft speeds to allow for a smooth shift. This function is left up to the driver. This can be noticed if a shift into 1st or reverse is attempted while the vehicle is rolling or before the input shaft stops rotating leading to a gear grind. The grinding can be reduced by coming to a complete stop and pausing for a moment before shifting into the 1st or reverse gear. Some slight grinding can be expected. In medium duty non-synchronized transmissions, the driver must match input shaft (engine) speed to output shaft (driveshaft) speed with every shift. This can be accomplished by double clutching, or by using other methods. If the driver is not able to perform this function properly, there will be gear grinding with each improperly completed shift. Driver training may be required to correct this condition. Clutch brakes are used in medium duty non-synchronized transmissions to allow a shift into gear at a stop. The clutch brake is used to stop the input shaft from spinning, allowing a shift into gear at a stop without grinding. The clutch brake is activated by pressing the clutch pedal all the way to the floor. When the clutch brake is used, it is possible to have a blocked shift with the vehicle stationary. If this occurs, engage the clutch slightly to rotate the input gear to allow the shift. The clutch brake is intended to only be used while at a stop. Care must be taken to not activate the clutch brake while shifting between gears. This could lead to excessive grinding or a blocked or missed shift.
Subject: Info - Manual Transmission Operating Characteristics #03-07-29-004C - (08/28/2006)
Models: 2007 and Prior Passenger Cars and Light Duty Trucks (Including Saturn)
2007 and Prior Chevrolet and GMC Medium Duty Trucks with Manual Transmission
Important: Even though this bulletin attempts to cover operating characteristics of manual transmissions, it cannot be all inclusive. Be sure to compare any questionable concerns to a similar vehicle and if possible, with similar mileage. Even though many of the conditions are described as characteristics and may not be durability issues, GM may attempt to improve specific issues for customer satisfaction.
The purpose of this bulletin is to assist in identifying characteristics of manual transmissions that repair attempts will not change. The following are explanations and examples of conditions that will generally occur in all manual transmissions. All noises will vary between transmissions due to build variation, type of transmission (usually the more heavy duty, the more noise), type of flywheel and clutch, level of insulation, etc.
Basic Information
Many transmission noises are created by the firing pulses of the engine. Each firing pulse creates a sudden change in angular acceleration at the crankshaft. These changes in speed can be reduced with clutch damper springs and dual mass flywheels. However, some speed variation will make it through to the transmission. This can create noise as the various gears will accel and decel against each other because of required clearances.
Gear Rattle
Rattling or grinding (not to be confused with a missed shift type of grinding, also described as a combustion knock type of noise) type noises usually occur while operating the engine at low RPMs (lugging the engine). This can occur while accelerating from a stop (for example, a Corvette) or while operating at low RPMs while under a load (for example, Kodiak in a lower gear and at low engine speed). Vehicles equipped with a dual-mass flywheel (for example, a 3500 HD Sierra with the 6-speed manual and Duramax®) will have reduced noise levels as compared to vehicles without (for example, a 4500 Kodiak with the 6-speed manual and Duramax®). However, dual-mass flywheels do not eliminate all noise.
Neutral Rattle
There are often concerns of rattle while idling in neutral with the clutch engaged. This is related to the changes in angular acceleration described earlier. This is a light rattle, and once again, vehicles with dual mass flywheels will have reduced noise. If the engine is shut off while idling in neutral with the clutch engaged, the sudden stop of the engine will create a rapid change in angular acceleration that even dual mass flywheels can not compensate. Because of the mass of all the components, this will create a noise. This type of noise should not be heard if the clutch is released (pedal pushed to the floor).
Backlash
Backlash noise is created when changing engine or driveline loading. This can occur when accelerating from a stop, coming to a stop, or applying and releasing the throttle (loading and unloading the driveline). This will vary based on vehicle type, build variations, driver input, vehicle loading, etc. and is created from the necessary clearance between all of the mating gears in the transmission, axle(s) and transfer case (if equipped).
Shift Effort
Shift effort will vary among different style transmissions and synchronizer designs. Usually the more heavy duty the transmission, the higher the shift effort because of the increased mass of the components. Shift effort can also be higher in cold weather because the fluid will be thicker. Medium duty transmissions will not shift as quickly as a Corvette transmission. To reduce shift effort, do not attempt to rush the shift - allow the synchronizers to work as designed. Shifting harder will only increase the chance of rushing past the synchronizer leading to grinding while shifting.
Non-Synchronized Gears
Some light duty truck transmissions in 1st gear (creeper-gear) and reverse gears in various transmissions, along with all gears in some medium duty transmissions, may be non-synchronized. This means there is not a mechanism to match input and output shaft speeds to allow for a smooth shift. This function is left up to the driver. This can be noticed if a shift into 1st or reverse is attempted while the vehicle is rolling or before the input shaft stops rotating leading to a gear grind. The grinding can be reduced by coming to a complete stop and pausing for a moment before shifting into the 1st or reverse gear. Some slight grinding can be expected. In medium duty non-synchronized transmissions, the driver must match input shaft (engine) speed to output shaft (driveshaft) speed with every shift. This can be accomplished by double clutching, or by using other methods. If the driver is not able to perform this function properly, there will be gear grinding with each improperly completed shift. Driver training may be required to correct this condition. Clutch brakes are used in medium duty non-synchronized transmissions to allow a shift into gear at a stop. The clutch brake is used to stop the input shaft from spinning, allowing a shift into gear at a stop without grinding. The clutch brake is activated by pressing the clutch pedal all the way to the floor. When the clutch brake is used, it is possible to have a blocked shift with the vehicle stationary. If this occurs, engage the clutch slightly to rotate the input gear to allow the shift. The clutch brake is intended to only be used while at a stop. Care must be taken to not activate the clutch brake while shifting between gears. This could lead to excessive grinding or a blocked or missed shift.
03-04-2017, 08:38 PM
#17
Yes!
That is exactly what it sounds like. Infact, I almost titled my post "Marbles in my exhaust" I really think the sound is coming from somewhere in the middle of the vehicle. I do not have anyone around me right now to push on the gas while I listen outside of the driver seat.
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rams drop, the sound is there again.
That is exactly what it sounds like. Infact, I almost titled my post "Marbles in my exhaust" I really think the sound is coming from somewhere in the middle of the vehicle. I do not have anyone around me right now to push on the gas while I listen outside of the driver seat.
I should have mentioned the car, unfortunately, is an automatic. I can just hear after a gear change and the rams drop, the sound is there again.
My Corvette is a 2000. It only has 21,000 miles. I bought it summer 2016 with 19,000 miles. I noticed that sound the 3rd or 4th time I drove it. It scared the crap out of me! I even made a post about it on here. If you do a Google search (I think I typed "marble and metal sound and C5 Corvette), a bunch of C5 owners have said the same thing.
Whatever it is, it's nothing bad. I had 3 very, very good local mechanics do both diagnostic tests and test drive my Corvette before I bought it. All of them said its running like a champ. It passed a state inspection with no problem at all (including emissions), so the cats must be just fine (or so I would assume?).
Again...don't panic. Since both of ours does it, that makes me even more confidant it's not something terrible or out of the norm. I'm taking it to a top notch Corvette Shop for some stuff in April. I'll ask them about it and see what they say and post results. In the meantime, enjoy the car and don't lose sleep. I lost sleep over that sound in the beginning (yes--seriously), but I've driven the car about 40 times totaling 2,000 miles since I got it and...nothing.
BTW...what year is yours and mileage?
03-04-2017, 08:45 PM
#18
Heel & Toe
Thread Starter
So first...don't panic. Like I said, my Caprice made the same sound for 100,000 of it's 200,000 miles and it never caused anything bad.
My Corvette is a 2000. It only has 21,000 miles. I bought it summer 2016 with 19,000 miles. I noticed that sound the 3rd or 4th time I drove it. It scared the crap out of me! I even made a post about it on here. If you do a Google search (I think I typed "marble and metal sound and C5 Corvette), a bunch of C5 owners have said the same thing.
Whatever it is, it's nothing bad. I had 3 very, very good local mechanics do both diagnostic tests and test drive my Corvette before I bought it. All of them said its running like a champ. It passed a state inspection with no problem at all (including emissions), so the cats must be just fine (or so I would assume?).
Again...don't panic. Since both of ours does it, that makes me even more confidant it's not something terrible or out of the norm. I'm taking it to a top notch Corvette Shop for some stuff in April. I'll ask them about it and see what they say and post results. In the meantime, enjoy the car and don't lose sleep. I lost sleep over that sound in the beginning (yes--seriously), but I've driven the car about 40 times totaling 2,000 miles since I got it and...nothing.
BTW...what year is yours and mileage?
My Corvette is a 2000. It only has 21,000 miles. I bought it summer 2016 with 19,000 miles. I noticed that sound the 3rd or 4th time I drove it. It scared the crap out of me! I even made a post about it on here. If you do a Google search (I think I typed "marble and metal sound and C5 Corvette), a bunch of C5 owners have said the same thing.
Whatever it is, it's nothing bad. I had 3 very, very good local mechanics do both diagnostic tests and test drive my Corvette before I bought it. All of them said its running like a champ. It passed a state inspection with no problem at all (including emissions), so the cats must be just fine (or so I would assume?).
Again...don't panic. Since both of ours does it, that makes me even more confidant it's not something terrible or out of the norm. I'm taking it to a top notch Corvette Shop for some stuff in April. I'll ask them about it and see what they say and post results. In the meantime, enjoy the car and don't lose sleep. I lost sleep over that sound in the beginning (yes--seriously), but I've driven the car about 40 times totaling 2,000 miles since I got it and...nothing.
BTW...what year is yours and mileage?
That makes me feel so much better!
It is a 2002, 70k.
I bought it yesterday from an old retired Navy guy.
He kept it in a garage its whole life and babied it!
Look at that interior (that is water from my shoes on the mats, not discoloration).. not too bad for a 15 yr old car!
I can hardly sleep I am just so excited to have it.
03-04-2017, 09:08 PM
#19
That makes me feel so much better!
It is a 2002, 70k.
I bought it yesterday from an old retired Navy guy.
He kept it in a garage its whole life and babied it!
Look at that interior (that is water from my shoes on the mats, not discoloration).. not too bad for a 15 yr old car!
I can hardly sleep I am just so excited to have it.
It is a 2002, 70k.
I bought it yesterday from an old retired Navy guy.
He kept it in a garage its whole life and babied it!
Look at that interior (that is water from my shoes on the mats, not discoloration).. not too bad for a 15 yr old car!
I can hardly sleep I am just so excited to have it.
I remember that feeling when I got mine over the summer. I went from a Caprice to a Cavalier to a Cobalt to a Corvette. It was like I hit the lottery.
I actually stood in the garage eating my dinner and staring at the car the first few days I had it. 
These cars are great, aren't they?! Do you know about the "new C5 owners checklist"? As in, the things you want to check and possibly replace? If not...I can post some "problem" things you should look for with these cars. Luckily, it's just a bunch of more minor things...nothing crazy. Worst case scenario, you might have to replace harmonic balancer (about $1,000 or so including labor and part). And that would be a worst case scenario for the most part.
In the "General Topic" section of this site, you should see the repairs some Porsche, M-B, BMW, Audi owners have had to do...like 5x the cost of C5 repairs. Considering these are still, 13+ years after they stopped manufacturing them, some of the fastest, most technologically advanced cars on the road really tells you how great they are.
As for the sound, I'll definitely let you know what the awesome Corvette Shop tells me. If anybody knows what it is, it will be them. But considering I've had 3 mechanics inspect and drive it, passed state inspection with emissions, and driven with no check engine lights or any codes on the DIC, I'm sure it's just something that has to be tightened or some hardware has to be replaced or some other minor fix. The computers on these cars (the DIC) seem to have codes for almost anything and everything that can go wrong (within reason), so if it's not there and the car drives well, and it definitely doesn't seem like any transmission or differential issue, I wouldn't worry about it.
03-04-2017, 09:33 PM
#20
Heel & Toe
Thread Starter
Beautiful Corvette. Enjoy it!
I remember that feeling when I got mine over the summer. I went from a Caprice to a Cavalier to a Cobalt to a Corvette. It was like I hit the lottery. I actually stood in the garage eating my dinner and staring at the car the first few days I had it. These cars are great, aren't they?!
Do you know about the "new C5 owners checklist"? As in, the things you want to check and possibly replace? If not...I can post some "problem" things you should look for with these cars. Luckily, it's just a bunch of more minor things...nothing crazy. Worst case scenario, you might have to replace harmonic balancer (about $1,000 or so including labor and part). And that would be a worst case scenario for the most part.
In the "General Topic" section of this site, you should see the repairs some Porsche, M-B, BMW, Audi owners have had to do...like 5x the cost of C5 repairs. Considering these are still, 13+ years after they stopped manufacturing them, some of the fastest, most technologically advanced cars on the road really tells you how great they are.
As for the sound, I'll definitely let you know what the awesome Corvette Shop tells me. If anybody knows what it is, it will be them. But considering I've had 3 mechanics inspect and drive it, passed state inspection with emissions, and driven with no check engine lights or any codes on the DIC, I'm sure it's just something that has to be tightened or some hardware has to be replaced or some other minor fix. The computers on these cars (the DIC) seem to have codes for almost anything and everything that can go wrong (within reason), so if it's not there and the car drives well, and it definitely doesn't seem like any transmission or differential issue, I wouldn't worry about it.
I remember that feeling when I got mine over the summer. I went from a Caprice to a Cavalier to a Cobalt to a Corvette. It was like I hit the lottery.
I actually stood in the garage eating my dinner and staring at the car the first few days I had it. These cars are great, aren't they?! Do you know about the "new C5 owners checklist"? As in, the things you want to check and possibly replace? If not...I can post some "problem" things you should look for with these cars. Luckily, it's just a bunch of more minor things...nothing crazy. Worst case scenario, you might have to replace harmonic balancer (about $1,000 or so including labor and part). And that would be a worst case scenario for the most part.
In the "General Topic" section of this site, you should see the repairs some Porsche, M-B, BMW, Audi owners have had to do...like 5x the cost of C5 repairs. Considering these are still, 13+ years after they stopped manufacturing them, some of the fastest, most technologically advanced cars on the road really tells you how great they are.
As for the sound, I'll definitely let you know what the awesome Corvette Shop tells me. If anybody knows what it is, it will be them. But considering I've had 3 mechanics inspect and drive it, passed state inspection with emissions, and driven with no check engine lights or any codes on the DIC, I'm sure it's just something that has to be tightened or some hardware has to be replaced or some other minor fix. The computers on these cars (the DIC) seem to have codes for almost anything and everything that can go wrong (within reason), so if it's not there and the car drives well, and it definitely doesn't seem like any transmission or differential issue, I wouldn't worry about it.
Thats a really good point about the DIC. It has a code for just about anything and everything and its not giving me one for that so Im not going to worry. I'll crawl up under and let you know what I find as well.
I test drove a few foreign cars just for good measure, but just kept coming back to the C5 and I am very glad I did.
As far as that checklist, I actually printed it out and took it with me to the guys house. It was very helpful. Thanks for mentioning it though!