Noisy Interior
Thread Starter
Instructor
Joined: Aug 2010
Posts: 119
Likes: 47
From: TX
Noisy Interior
I've had a 1970 convertible, a 1996 convertible, a 1996 coupe, and now a 2002 with the Targa top. Perhaps I'm spoiled, but compared to my Ram, Honda Accord, and SL500, the C5 is really noisy driving over 50 - 60. It's even louder than my wife's Santa Fe.
Just curious if this is fairly common. I've checked the hatch seal and plan to remove the top and inspect that seal also. The noise isn't really the wind noise whistling, just road noise and obnoxiously loud in general.
Just curious if this is fairly common. I've checked the hatch seal and plan to remove the top and inspect that seal also. The noise isn't really the wind noise whistling, just road noise and obnoxiously loud in general.
Drifting
Joined: Sep 2022
Posts: 1,350
Likes: 1,018
Yes, they are loud inside.
I quieted mine down by a HUGE amount with some sound deadener installation, covered all the cargo area and rear wheel wells, night and day difference.
I also got rid of a ton of rattles and squeaks with the installation of C7 seats.
I quieted mine down by a HUGE amount with some sound deadener installation, covered all the cargo area and rear wheel wells, night and day difference.
I also got rid of a ton of rattles and squeaks with the installation of C7 seats.
Le Mans Master
Joined: Jul 2010
Posts: 5,986
Likes: 719
I've had a 1970 convertible, a 1996 convertible, a 1996 coupe, and now a 2002 with the Targa top. Perhaps I'm spoiled, but compared to my Ram, Honda Accord, and SL500, the C5 is really noisy driving over 50 - 60. It's even louder than my wife's Santa Fe.
Just curious if this is fairly common. I've checked the hatch seal and plan to remove the top and inspect that seal also. The noise isn't really the wind noise whistling, just road noise and obnoxiously loud in general.
Just curious if this is fairly common. I've checked the hatch seal and plan to remove the top and inspect that seal also. The noise isn't really the wind noise whistling, just road noise and obnoxiously loud in general.
Thread Starter
Instructor
Joined: Aug 2010
Posts: 119
Likes: 47
From: TX
Removed the top and adjusted the seal, also coated it with seal-glide. Found a major issue while inspecting the seals. All seals are good, but the passenger glass is not seated correctly in the window regulator and needs to be adjusted about 1/4" toward the rear. That should make a difference. I'm going to look into some sound deadening mat for the cargo area and floorboards.
Le Mans Master
Joined: Feb 2021
Posts: 6,442
Likes: 4,278
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
2022 C5 of the Year Finalist - Unmodified
Removed the top and adjusted the seal, also coated it with seal-glide. Found a major issue while inspecting the seals. All seals are good, but the passenger glass is not seated correctly in the window regulator and needs to be adjusted about 1/4" toward the rear. That should make a difference. I'm going to look into some sound deadening mat for the cargo area and floorboards.
Melting Slicks
Joined: Mar 2023
Posts: 2,896
Likes: 1,658
From: North Coast
Much noise is due to tires and engine.
Being a sports car both are expected.
note the tires on the rear are the width of 4 regular SUV tires in some cases. They have aggressive tread and make noise. Less sound damping contributes to the noise. Coupes can amplify the sound.
Being a sports car both are expected.
note the tires on the rear are the width of 4 regular SUV tires in some cases. They have aggressive tread and make noise. Less sound damping contributes to the noise. Coupes can amplify the sound.
Thread Starter
Instructor
Joined: Aug 2010
Posts: 119
Likes: 47
From: TX
Did anyone use blankets or pads to see where to most effective area areas are before installing deadening? Not sure if it will work, but I plan to test it out next week.
Last edited by TSheff; Nov 25, 2025 at 04:52 PM.
Melting Slicks
Joined: Oct 2022
Posts: 2,743
Likes: 2,250
From: Phoenix, Arizona
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
could be gearing, auto or manual??
my '04 c5 a4, 2.73, 80@1800 is a raw, rough ride, compared to 2014 z51 vert, which is surprisingly quiet with rf's/top down!!
my '04 c5 a4, 2.73, 80@1800 is a raw, rough ride, compared to 2014 z51 vert, which is surprisingly quiet with rf's/top down!!
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Drifting
Joined: Sep 2022
Posts: 1,350
Likes: 1,018
Much like the Harley Forum, same format and probably same owners, the Forum search function is very lacking.
Did anyone use blankets or pads to see where to most effective area areas are before installing deadening? Not sure if it will work, but I plan to test it out next week.
Did anyone use blankets or pads to see where to most effective area areas are before installing deadening? Not sure if it will work, but I plan to test it out next week.
As to sound deadening, using blankets to test is not going to be very effective, the sound is transmitted by vibration, the deadening works by being attached firmly to the panels, blankets won't do that.
Drifting
Joined: Sep 2017
Posts: 1,957
Likes: 688
From: Avon Lake OH
Advanced
Joined: Jan 2023
Posts: 75
Likes: 36
From: near San Antonio TX
I did sound deadening & heat barrier install,
Quiet a cool now.
I have a stock exhaust w/soft ride FE1 suspension
Quiet a cool now.
I have a stock exhaust w/soft ride FE1 suspension
Last edited by donjetman; Nov 28, 2025 at 03:53 PM.
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
It's a 20+ year old, with old weather seals, plastic car with plastic interior, wide tires and a performance engine with nonexistent noise reducing insulation from the factory. Yeah, they are all "loud" in comparison to modern cars made of metal with ample sound deadening insulation. Especially if there's an aftermarket exhaust added to the mix.
Thread Starter
Instructor
Joined: Aug 2010
Posts: 119
Likes: 47
From: TX
It's a 20+ year old, with old weather seals, plastic car with plastic interior, wide tires and a performance engine with nonexistent noise reducing insulation from the factory. Yeah, they are all "loud" in comparison to modern cars made of metal with ample sound deadening insulation. Especially if there's an aftermarket exhaust added to the mix.
Potential Blasphemy, I have a 2004 SL500 (Convertible), as fast or faster, tires as wide, and it is quiet, top up or down.
Just ordered some 120Mil sound deadening material to work on the major target areas first. Going to focus on the areas directly behind the seats and the rear cargo area first. It will be a Work in Progress.
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
I get it and will deal with some of it. Seals are surprisingly good, no aftermarket exhaust, and yes, I may be making unfair comparisons.
Potential Blasphemy, I have a 2004 SL500 (Convertible), as fast or faster, tires as wide, and it is quiet, top up or down.
Just ordered some 120Mil sound deadening material to work on the major target areas first. Going to focus on the areas directly behind the seats and the rear cargo area first. It will be a Work in Progress.
Potential Blasphemy, I have a 2004 SL500 (Convertible), as fast or faster, tires as wide, and it is quiet, top up or down.
Just ordered some 120Mil sound deadening material to work on the major target areas first. Going to focus on the areas directly behind the seats and the rear cargo area first. It will be a Work in Progress.
Some sound deadening material in the tunnel, behind the seats and in the trunk will help.
My 2004 BMW 645ci convertible is MUCH quieter inside than my C5 coupe in every way. It's also a fat pig by comparison from a performance perspective (drives reallly nicely though) and was $30k more. The SL500 is in no way as fast stock vs. stock as a C5. Unless the C5 has the 2.73 gear and there's something wrong with it. My best friend traded his '01 Z06 in for an SL500 circa 2003. My m6 coupe at that time only had a catback and a Blackwing and I blew his doors off multiple times. From a dig and rolling.
The MB was a pleasure to drive but not nearly as fast as a healthy C5 with a 3.42 in stock form. Same as my 645ci, the MB is a nice driving car that's solid and full of sound deadening material. Which makes them overweight and ultimately slow by comparison. But different tools for different jobs
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
PS...that passenger window of yours being off kilter has a lot to do with added noise. I've had to adjust mine a few times over 25 years. When the glass isn't seated properly and the tip-in isn't correct it's as noisy as a frickin wind tunnel inside the car.
Thread Starter
Instructor
Joined: Aug 2010
Posts: 119
Likes: 47
From: TX
I'll do a little testing over the next couple of weeks, but at this point perhaps I'm not putting enough foot into the Vette. The SL feels more responsive to the pedal, definitely not a Fat Pig. I get we're talking Apples and Oranges, I was just expecting more Pep than I've felt so far. Also, aside from acceleration because of the noise the speed definitely doesn't sneak up on you in the Vette, while I have to watch the SL or I'll be going much faster than expected. Haven't and won't be testing on a road course, but they both handle very well.
Last edited by TSheff; Nov 28, 2025 at 09:51 PM.
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
Once you have that window sorted out, the in cabin noise reduction will be like night and day.
You didn't mention if you have an mn6 C5 or an A4. If you have an A4 which gearset does it have? The 2.73 being the slowest of all. The 3.15 being the performance option for the A4. But even the 2.73 will do the 1/4 under 14 seconds. The SL500 on the other hand does the 1/4 mile in just under 15 seconds. The SL having 40 less HP about 10 less torque and weighing almost 900 lbs more than the C5. The SL may feel faster to you, but its absolutely not. Unless there is something wrong with your vette (other than it being an auto LOL!).
I'm sure you'll find once the window is adjusted there is significant improvement on the noise.
You didn't mention if you have an mn6 C5 or an A4. If you have an A4 which gearset does it have? The 2.73 being the slowest of all. The 3.15 being the performance option for the A4. But even the 2.73 will do the 1/4 under 14 seconds. The SL500 on the other hand does the 1/4 mile in just under 15 seconds. The SL having 40 less HP about 10 less torque and weighing almost 900 lbs more than the C5. The SL may feel faster to you, but its absolutely not. Unless there is something wrong with your vette (other than it being an auto LOL!).
I'm sure you'll find once the window is adjusted there is significant improvement on the noise.
Melting Slicks
Joined: Dec 2004
Posts: 2,847
Likes: 1,144
From: Sleepy Hollow- NJ
PS...drive by wire does present a lag in throttle response in the C5. Especially in an A4. The factory tune on the shift points is also very soft. Having a performance tune will "wake it up" (even with all else being stock) from a throttle response and trans shiftpoint perspective. However, a better gear (3.42+) better converter, and the tune provides a much more effective performance improvement in an otherwise stock A4.
I test drove a stock A4 with 2.73 once. It was atrocious.
I test drove a stock A4 with 2.73 once. It was atrocious.
Le Mans Master
Joined: Feb 2021
Posts: 6,442
Likes: 4,278
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
2022 C5 of the Year Finalist - Unmodified
Much like the Harley Forum, same format and probably same owners, the Forum search function is very lacking.
Did anyone use blankets or pads to see where to most effective area areas are before installing deadening? Not sure if it will work, but I plan to test it out next week.
Did anyone use blankets or pads to see where to most effective area areas are before installing deadening? Not sure if it will work, but I plan to test it out next week.
https://www.corvetteforum.com/forums...of-kilmat.html
Quality butyl mat for the base, followed by foam. In acutely loud areas, like behind the seat, panel in front of the license plate, center section of cargo floor, and wheel wells benefit from a top layer of mass loaded vinyl (MLV). Good luck.