PLEASE HELP // Vibration through pedals and floor after exhaust install

[johnnydg]

Hi all. A quick recap of my issue. I have a 2011 e92 M3 that is ESS supercharged. I just installed AA X pipe and HFC. I took off my Macht Schnell race X pipe with straight pipes prior to this install. After installation i had very bad vibration through my pedals. The obvious thought is that the heat-shield is touching the piping. After hours of manipulation I can not find a place the heat shield is touching. I work for a Porsche dealership and have had multiple technicians help and try to figure out what is causing the vibration.

Tonight I had my shop foreman look at it and he found that my ESS supercharger is touching the frame of my car which he believes is causing a vibration. This is the black plastic piece that touches near the wheel well on the far right side of the engine bay. I can see the "MOTUL 600" written on the frame near where it is touching. I want to add that I do not recall this vibration with my Macht Schnell exhaust set up which leads me to believe this is not the cause of my issue.

Needless to say I am literally going crazy and so frustrated that I can not figure out what the issue is. Please if someone can chime in and help I am ready to take it to a BMW shop to see if they can fix this OR some indy shop here in Dallas (suggestions anyone?). I also am going to call ESS tomorrow to see if that piece is supposed to be touching the frame.

Sorry for the long post in advance - stress is taking over.

[roastbeef]

when was the last time you took a look at your engine mounts? bad engine mounts are the first thing that comes to mind.

[johnnydg]

I've had 3 techs look at the engine mounts and said they look okay. Any other thoughts? I don't have the black brace supporting the X pipe on - would this cause such a vibration?

[Cbozz]

I had AA x pipe with HFC and I ended up cutting the cats out and replacing them with straight pipes. I got a horrible vibrations though pedals and just when flooring it... It ended up bing the V-band clamp it was touching the bottom of the car. I ended up cutting the straight pipe and taking out about 3mm length and that helped but I still had a rattle and some vibration and it turned out to be a gasket that is on the end of the headers - they were used up and thin and the x pipe was rattling on the header pipe. I bought new gaskets and bam - it all went away!! check those gaskets.. here is a pic of a new one and my old one

[johnnydg]

Cbozz,

Thank you so much for your reply. I replaced the driver side gasket, and it seemed to help a little but on my drive home from work today the vibration was bad. I will replace the passenger side gasket too. I just can't believe the vibration would be coming from those. I want this fixed!!! Did you have your black brace that supported the X pipe on or did you take it off??

[Cbozz]

Originally Posted by johnnydg

Cbozz,

Thank you so much for your reply. I replaced the driver side gasket, and it seemed to help a little but on my drive home from work today the vibration was bad. I will replace the passenger side gasket too. I just can't believe the vibration would be coming from those. I want this fixed!!! Did you have your black brace that supported the X pipe on or did you take it off??

I left the brace the way it should be with OEM, AA fit dead on.. You should leave that there
also listen to the video in my thread and maybe it sounds similar.. and that's header rattle

http://www.m3post.com/forums/showthr...3#post21556233

[johnnydg]

Mine is strictly a vibration through the pedals and through the shifter, I don't hear any rattling at all. I'm hopeful putting the brace and replacing the passenger side gasket will fix things. Could it also be something to do with the headers?

[johnnydg]

After tonight, having multiple techs ride and drive with the vehicle the consensus is that the vibration is resonance from the X-pipe HFC area. It is resonating into the body of the car, the floor and the pedals and shifter. It is very pronounced. I replaced the gaskets that connect the header pipe to the HFC. The vibration is still there. I really don't know what else to do, I'm really frustrated at this point.

Could the welding on the cats cause this issue? Could anything else cause this issue? We don't see it touching anywhere under the car or on the heat shield.

I also wanted to add that my car is supercharged through ESS. Would this amplify or cause the issue to worsen?

[Cbozz]

Originally Posted by johnnydg

After tonight, having multiple techs ride and drive with the vehicle the consensus is that the vibration is resonance from the X-pipe HFC area. It is resonating into the body of the car, the floor and the pedals and shifter. It is very pronounced. I replaced the gaskets that connect the header pipe to the HFC. The vibration is still there. I really don't know what else to do, I'm really frustrated at this point.

Could the welding on the cats cause this issue? Could anything else cause this issue? We don't see it touching anywhere under the car or on the heat shield.

I also wanted to add that my car is supercharged through ESS. Would this amplify or cause the issue to worsen?

When you accelerate you engine shakes or vibrates and that causes exhaust pipes to vibrate so you need a lot of clearance between those and the car body... AA x pipe has pretty thick v bands connecting test pipes you can try lowering test pipes on the header and that will move the exhaust away from the car.. that was my problem when I ended up cutting out some of the pipe to make test pipes slide lower on the header and that solved most of my vibration except a bad gasket... try that- you may have to move the entire exhaust back toward the rear of the car but try shimming test pipes lower on the header and you'll get a lot of clearance that way... it must be exhaust... also check your heat shield near your drive shaft by the differential.. maybe something pushed it and now it's touching.. should be about an inch of clearance there..

[johnnydg]

still having the vibration. can not see the heat shield touching anywhere... Please help?

[bkdore]

Originally Posted by johnnydg

still having the vibration. can not see the heat shield touching anywhere... Please help?

Have you tried switching the exhaust back and see if the problem goes away?

[johnnydg]

i unfortunately sold the old exhaust. If anyone is in Dallas and will let me swap exhausts to see if that fixes the issue I would really appreciate it.

[johnnydg]

Update:

Active Auto is sending my straight pipes to see if replacing the High Flow Cats will result in the issue going away. I'm so frustrated with this whole thing - not being able to isolate the issue.

[johnnydg]

Update:

I have taken it to Cobb tuning here in Dallas. They came to the conclusion that the vibration is being caused from the exhaust and is not from anything touching. It is just the decibel of the exhaust and they can't really fix it. After spending $500 and about 20 hours of time I think its time to throw in the towel and admit that the exhaust from AA is a failure and it has either been manufactured incorrectly or my car just sucks. Any other tips or ideas? I don't want to run with a straight pipe and i'm afraid OEM cats will get too hot and I will need a retune from ESS due to my supercharger which i'm not sure if they will charge me $ for.

Any ideas for supplementing the AA X pipe and HFC for something else would be greatly appreciated.

[8600RPM]

Sound resonates down metal and although you may think that little black brace has plenty of room, when the exhaust heats and expands it hits unless you put a couple spacers or washees to give more clearancewashers

[johnnydg]

I've tried with the black brace on and off. still the same vibration

[Cbozz]

Originally Posted by johnnydg

I've tried with the black brace on and off. still the same vibration

hey I'm in Dallas till Thursday, I can meet you and maybe listen to it and see if it sounds familiar? let me know!

[johnnydg]

I wanted to add to this thread that when I drive in rain the throttle pedal vibrates violently. I'm not sure what is causing this.

[johnnydg]

Update:

Installed and took off straight pipes instead of the HFC. The vibration in the shifter went away and the vibration in the floor and pedals definitely went down but was still there. This vibration is not from anything physically touching - it is from the exhaust vibrating the car. I'm worried that something must be wrong with the car for it to be lightly vibrating at all. the vibrating feels like the pedal is tickling your foot and the same feeling with the floor. Any ideas?

[Jive]

Did you ever get this completely resolved? I previously had the AA HFC x-pipe with AA exhaust which did not cause pedal vibration. I just installed AA HFC x-pipe with OEM exhaust. After switching to AA x-pipe and OEM exhaust, the pedal vibration appeared under hard acceleration and is pretty strong. It was not there previously when I had the full AA set up.

Edit: I have a DCT and I don't feel any vibration in the shifter.