Ive had the M2 exhaust on my IS350 for a little over a year and it vibrates a lot when driving low speeds in high gear and also when just driving normally. Is there anyway to dampen the vibrations? Or does anybody know of reasons why this would be happening or is just the way this exhaust sounds?

thanks

 

Are you hearing metal on metal contact?

If so, make sure the exhaust is not contacting your heat shield. Also, it is possible that the "support piece" that is welded to the two pipes that split from the flange has broken and is loose.

Crawl under the car and do some investigation... should be an easy fix. Your exhaust should not have any vibration related noises coming from it.

 

Its not metal on metal, like the interior vibrates, when accelerating you feel vibrations in the seat and doors. Coins in the center console will make some noise sometimes

 

And it also very loud when it vibrates most.

 

It should not do that.

With the car on, look around the exhaust area and try to hear the noise outside; hold/ move/ push on the exhaust (use gloves or your shoes, it may be really hot) to push a bit on the tips to see if that makes the noise go away, if that is the case; Just check and re do all the bolts.

If that is not the issue, you could have a bad mufflers or CAT..Sometimes the inside elements get busted, specially the CATs, you will not get a CEL as they work but they usually rattle when the car is cold after it is warms up it usually goes away.

 

It sounds fine at idle but I will check for leaks or contact with other parts. And it also is quieter when cold but once the engine warms up it gets louder and the vibrations start to get worse. It vibrates at it worst when in 5th or 6th gear at low speeds and when accelerating up a hill in high gear

 

Something is definitely not right... the M2 exhaust is on the quieter side when it comes to exhausts. I have had mine on for over a year and I've never experienced any sort of unusual cabin noise or vibrations due to exhaust noise.

 

1 of 2 things is happening.

1. Either there is a leak or there is contact with the body somewhere along the line of the exhaust. I would inspect all the gaskets as well as how the exhaust is seated. My accord used to do that with an axle back exhaust and it was because it got too close to close to the aftermarket sway bar I installed. I would feel it all over the car at lower RPMs. I replaced all the rubber exhaust mounts/Hangers with one that was a 1/4 inch longer and it went away.

or

2. your exhaust baffle is going bad making the exhaust get louder and droning more through out the car. Not necessarily your M2 axleback but could be at the center muffler/Resonator that the baffle is going bad too

I would try changing the rubber mounts since you can get a pack of 4 at the auto store for like 7 bucks. I used the hangers from a chevy pickup cuz it was the only one i found longer than the accord. Measure yours and try it out before going to inspect your baffle in the resonator cuz that would cost more

 

By rubber mounts do you mean the hangers that hold the exhaust up? I will check to see if it there is any contact with other parts of the car which is possible because when I first installed it, it was banging into something so I had to adjust it but the adjustment may not have been enough

 

Its most likely the exhaust hangers.

 

Should I get longer hangers so the exhaust sits lower?

 

That is what i would recommend. It is the cheapest and easiest solution. If it work, you only spend 7-10 bucks which I'm about 90% positive that it will work if you are sure there are no exhaust leaks

 

Yes you should get new longer exhaust hangers if it is rubbing onto something. If not then maybe you just need new hangers.

 

I just checked and there is nothing hitting anywhere. I even shook the exhaust as much as I could and nothing hit. Revving it up with out driving it sounds fine and doesnt vibrate or anything, from the outside it doesnt sound like there are any leaks. Any other possibilities?

 

How can i tell if there is a leak besides just listening?