Weird noise......looking for some help.
Thread Starter
Intermediate
Joined: Dec 2010
Posts: 41
Likes: 0
From: Saint Augustine FL
Weird noise......looking for some help.
Hey everybody.....I did a search but I could not find anything sounding like the problem I'm having. I just got the car right before Christmas.....she runs PERFECT....no misses...no hesitation.....not thowing any codes. All seems fine but the other day I had the car running and got out to grab something and I heard a noise from behind the car. It's coming from the driver's side muffler (Flowmaster). It's a very quiet "popping" sound. You can't hear it from inside or when you're driving the car. You almost have to bend down and put your ear right by the muffler. The other side does not made the noise. It's not like the "popping" sound you might get on deceleration.....just a quiet "pop...pop pop". I did have my wife get in the car and give it some gas while I listened.......the "popping" get faster as the revs go up. Like I said.....all seems fine with the car.......no codes......run like a bat out of HECK.......I might have never heard this if I was not walking behind the car while it was running. I was about to take the car for a spin on the dyno to confirm the previous owners tune and HP numbers.....but now I'm a little concerned. Anybody ever have this sound??? 
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Once you put headers on a car you can get all kinds of weird noises. Since I put my headers on I have poping, ticking, and a few other strange noises, but as long as there behind the motor and not in it, Im ok with it....WW
Thread Starter
Intermediate
Joined: Dec 2010
Posts: 41
Likes: 0
From: Saint Augustine FL
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
If it's only on one side, you probably have a pinhole leak somewhere between the resonator( if you still have one) and the muffler on that side. I would first suspect one of the weld points, as these tend to rust quickly if not painted for protection. Or it could have been there all along. Even the most skilled welders have difficulty getting the top when they weld mufflers and such while on the car.
A supercharged 383 sounds like alot of fun
A supercharged 383 sounds like alot of fun
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
The other main cause besides leaks of a pop, if it is in sync with engine RPM is an exhaust valve not fully sealing when it closes, this will cause a subtle pop sound every time that cylinder fires as some of the explosion gets past the valve.
Worst case is a bent or burnt valve, almost 99% it won't be. Next common cause is a misadjusted or defective lifter, common but unlikely. Most common cause is just plain old carbon build up on the valve seat. For that I have had great success with a product called SeaFoam. Downside to a TPI is the horizontal air flow, SeaFoam is in a can, not a spray and you pour it down the throttle body of a warm engine just short of fast enough to stall it. Then shut it down and let it sit wet for 15 mins. Start it up and be prepared to dissappear in the smoke!
It can take some of the roughest idling motors and cure that too if the idle is just because of gunk and carbon. You can also use it in the gas tank, but I never found it worked as well as the pour and soak method. I use it in my cars, boat and old John Deere.
Worst case is a bent or burnt valve, almost 99% it won't be. Next common cause is a misadjusted or defective lifter, common but unlikely. Most common cause is just plain old carbon build up on the valve seat. For that I have had great success with a product called SeaFoam. Downside to a TPI is the horizontal air flow, SeaFoam is in a can, not a spray and you pour it down the throttle body of a warm engine just short of fast enough to stall it. Then shut it down and let it sit wet for 15 mins. Start it up and be prepared to dissappear in the smoke!
It can take some of the roughest idling motors and cure that too if the idle is just because of gunk and carbon. You can also use it in the gas tank, but I never found it worked as well as the pour and soak method. I use it in my cars, boat and old John Deere.
