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exhaust vibration

10K views 14 replies 10 participants last post by  Derek SRT8 
#1 ·
I have a 08 srt that have replaced the suitcase muffler and deleted rear resonators. the car was okey for about a year with this but the past 2 seasons I have gotten a vibration that is either coming from under car or from engine compartment. it usually comes at just over 1,000 rpm (about 1.5 to 1 and three quarters). everywhere else on the tach is okey. anybody else have this problem? so hard to pinpoint area. not sure if one of the original heat shields bolted to floor are loose or the exhaust is vibrating and hitting something or just at that rpm is making exhaust vibrate. it is something like a blastin bobs idea setup but with a set of ravin mufflers instead with the rear resonators replaced with straight pipes done at my local muffler shop about 3 years ago. just wondering if anyone else has had this sort of problem. getting a little irritating. car sounds great with this setup until you hit the right rpm. at highway speed at 90 klms per hour it is just barely out of this rpm so it is happening pretty frequently.
 
#2 ·
I have the Blastin Bobs and i notice some vibration as you describe. I figure the pipes are to close to the floor or something, sounds like its under the trunk not up front. When the weather cools i will get under there to see where its hitting.


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#3 ·
Funny, I have a viberation at 1500 rpm. When barley on the throttle cruzing, you ease out of throttle totally and soon as it get to 1500 its a viberation. Feels like its kicking into 4 banger mode with MDS but I dont have it. MDS is removed from the motor and disabled in the tune of course. Every where else its ok, no vibs. Or get back slightly back in the gas and bring up rpm and it stops. It dont stay viberating if you hold 1500rpm it wont viberate. Again only during de excell foot off gas when hits 1500rpm at any MPH. Nothing hitting frame or anything, not that type of vib.. wierd stuff....
Not really in the drive train either, I dont think. I thought it was the ac compressor. Its Not. Drive shaft I checked and is new carbon fiber, axels just replaced new, Not the tires, so I dont know.
Thought maybe the converter is going bad ,or something in the trans was out of balance. Or even a flex plate. Just feels like motor. Hell I dont know but im looking. Really stuck.
FlatTop
PS let me know what you find out.
 
#5 ·
I had the same vibration on my R/T after installing a solo cat back system. Drove me nuts as it made the car sound like a piece of ---- . Looked everywhere and could not track down the vibration. When I installed the stage one lowering springs I had to take the rear portion of the exhaust off on both sides so that I could drop the lower control arm. When I reinstalled the exhaust I made sure to get the rear section straight and tightened it down very tight.
On my test drive I noticed immediately that the vibration was gone. The vibration has not come back. Don't know exactly what I changed just thought it may be something to look at.
 
#7 ·
Dealing with this EXACT issue just as you described. I had the Flowmaster American Thunder catback exhaust installed by a muffler shop. I started to experience the same vibration that you mentioned after about a week running the new exhaust. I talked to Flowmaster and they knew it was a Dodge Challenger as I was describing the issue. They sent me new tips and I installed them and the sound disappeared...for about a week! The vibration in the same condition came back just like before. They originally said the tips were manufactured incorrectly and they had to swap suppliers. Oddly, the new tips looked identical to the old ones.

So now I'm still dealing with the same issues. This time I'm taking my car to a proffesional muffler shop to see if they agree that the tips are bad. Flowmaster has said they would send two new tips, but recommended I weld them seamless so there is no gaps. I'm almost tempted to put my stock tips on to see how they perform. Taking it in to the muffler shop next week to see what they say. I'll post what I find when I finally get this resolved.
 
#9 ·
Get your lazy butts under your cars and look for rub marks. Chances are it is the exhaust and just needs to be loosened up and reset for proper spacing.

I had same issues when I redid my exhaust at around the same RPM's. Took me 3 tries to set it properly as it was rubbing back around the rear diff framing.
 
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#10 ·
make sure your exhaust is not close to the crossmember or anything....when you accelerate, your engine twists and so does the exhaust. I believe Speedlogix sells a crossmember or w/e it's called with more clearance for the exhaust. Some people have placed washers to bring it out more.
 
#11 ·
Most of the time it's due to improper installation. When all the piping required for the true dual system it's sometimes a problem when the pipes are hitting underneath the car. There should be at least 1/2" between the pipe and any undercarriage part of the car.

You may want to have that professional muffler shop REINSTALL or reset the whole system. Take each pipe out, and take a mallet with a piece of wood and smack those pipes in as far as they will go. Once it's all setup, there shouldn't be any reason for noise/vibration unless there is a weak clamp. I'm not sure on the quality of clamps that Flowmaster gives to it's customers. Something to look into.
 
#13 · (Edited)
are the rubber grommets that hang the exhaust from worn out and have slop in them allowing the exhaust to hit somewhere???
 
#14 ·
I had the the same problem and found it was the resonator leaning on the rear just a bit when under acceleration. It made me nuts till it was found and fixed. I also have a 2011 Ram and have a exhaust vibration there and nobody can find it or even hear it. This coming spring a new comp/ system going on so hopefully it will be the end of that.
 
#15 ·
In regard to the lazy butt comment...how would you know what any of us have been through in regards to troubleshooting our issues? No need for comments like that.

As far as where I stand with my vibration issue, the muffler shop put my car up on the lift to look. They were able to diagnose the problem which was the exhaust tip again! When the pipes were flexed (bumped) it caused a gap in the tip which was vibrating. They tack welded the tip and the problem went away completely. Apparently I got another set of defective tips from Flowmaster. Not an issue any more though.

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