Exhaust Noise
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Exhaust Noise
Hey guys. 1994 LT1 6-Speed. No cats, X-pipe, stock mufflers. I am getting a strange buzzing, sort of a metal on metal vibration between 2-4000 RPM under light acceleration or deceleration. It is noticeable enough for me to hear it over the exhaust itself and radio. I am almost certain it is coming from the exhaust somewhere. I made sure all the hangers were tight, all flanges are snug and so is the slip joint on the passenger side. Wondering if any of you had run into something like this and had a solution?
Any help would be appreciated, starting to drive me nuts.
Any help would be appreciated, starting to drive me nuts.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
Happened to me too on the Corvette, and on two other cars. My S10 heat shield around the catalytic converter was really loud just from vibration.
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Cliff- That is what I was thinking, but I can't seem to locate it (if there is one). Car is pretty much quiet as stock while idling. Nothing seems to be rubbing.
Keystring and QCVette- There were heat shields when the cats were still on the car, the only heat shield I know of that remains is on the driver side exhaust pipe that leads into the X-Pipe. Seems to be on there sturdy enough but I'll double check.
Appreciate it guys.
Keystring and QCVette- There were heat shields when the cats were still on the car, the only heat shield I know of that remains is on the driver side exhaust pipe that leads into the X-Pipe. Seems to be on there sturdy enough but I'll double check.
Appreciate it guys.
Drifting
Joined: Nov 2002
Posts: 1,365
Likes: 3
From: Huntsville AL
Mine did the same thing when I first bought it, and it was a heat shied rattling. Can't remember which one, though.
You might want to check the metal shields for the knock sensors on the block. If those are loose, they might rattle. If one has come off, it might be rattling against the exhaust pipe or an O2 sensor.
You might want to check the metal shields for the knock sensors on the block. If those are loose, they might rattle. If one has come off, it might be rattling against the exhaust pipe or an O2 sensor.
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Mine did the same thing when I first bought it, and it was a heat shied rattling. Can't remember which one, though.
You might want to check the metal shields for the knock sensors on the block. If those are loose, they might rattle. If one has come off, it might be rattling against the exhaust pipe or an O2 sensor.
You might want to check the metal shields for the knock sensors on the block. If those are loose, they might rattle. If one has come off, it might be rattling against the exhaust pipe or an O2 sensor.
However, did find two small exhaust leaks on both the driver and passenger side. I plugged the tail pipes with shop rags and got under the car to listen. The passenger side is indeed leaking from the slip joint, and so is the driver side. It's not a terrible leak but enough to hear it and feel it on your hand. Both sides are clamped instead of welded, so looks like I'll be headed to the shop to have them welded up. Maybe this will solve some of the "glug glug glug glug" sound I was experiencing as well as the metallic sound.
Has anyone had any success fixing an exhaust leak with some exhaust puddy and those "easy seal" band clamps you can buy at auto parts stores? Like this:
http://www.sbsdieselperformance.com/images/EasySeal.gif
Anyways, I appreciate all the responses and I'll be sure to give an update
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Update:
Had both slip joints welded. No change at all.
Figured I would try and remove the heat shields on the exhaust manifolds. And this is what I found on the passenger side:
I've got a new manifold coming in on Thursday from LKQ. Hopefully this fixes my issues.
Had both slip joints welded. No change at all.
Figured I would try and remove the heat shields on the exhaust manifolds. And this is what I found on the passenger side:
I've got a new manifold coming in on Thursday from LKQ. Hopefully this fixes my issues.
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
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
. The manifold is in I will try and get it tackled tonight or early AM.
Thread Starter
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Went and got some "Thermo-Seal" 2000 degree manifold repair. Worked like a charm and sealed up the crack in the manifold. However, still have an annoying metallic buzzing sound. It's not exhaust drone it is definitely something vibrating against something... It is most noticeable at 65mph in 6th gear. It's horrible. All heat shields seem okay!
At a loss.
At a loss.
Racer
Joined: Jan 2008
Posts: 281
Likes: 3
From: Palm Coast FL
So it happens between 2000-4000 rpm only, even when parked? You have to try and isolate where it is coming from. Have you tried a mechanics stethascope thing?
Could it be alternator/water pump/compressor. Try running for a very short time with the drive belt off? Or is it coming from somewhere else?
Does it do it with the ac off?
I am a numpty when it comes to these things but you've got the same model as me with approx same mileage. Keep looking!
Could it be alternator/water pump/compressor. Try running for a very short time with the drive belt off? Or is it coming from somewhere else?
Does it do it with the ac off?
I am a numpty when it comes to these things but you've got the same model as me with approx same mileage. Keep looking!