Idle vibration after down pipe upgrade...

[HouTX87]

I seem to have a little bit of a rough idle since installing my 3" terry houston down pipe a few weeks ago. I think it may be more of a vibration than a rough idle because the car runs excellent, no miss or hesitation and the down pipe has good clearance. I never noticed this before. Any ideas? Does this sound normal? I have new motor mounts and all of the mods in my sig have been installed within the past 6 months. Before then the car was completely stock.

 

[HouTX87]

Anyone? I think I'll take a closer look to see if the downpipe is making contact with the body. I think that must be the issue.

 

[projectmoneypit]

yes, check for proper clearance as it maybe hittin something causing false knock, make sure to check while in gear with motor torqued also.

 

[turbo3.8]

If u only feel the vibration when in certain rpm and then goes away it might be ur down pipe comes in contact with the crossover pipe .

 

[HouTX87]

It's only at idle, whether in park or drive. Going down the road no problems at all. No false knock either. My dump pipe was a really tight fit getting it lined up to my catback, couldn't even fit the gasket in between that I got from gbodyparts. I thought maybe there was some stress on the exhaust system causing some vibration. I plan to replace my catback very soon. Right now I have a flowmaster catback with the single crossflow muffler.

 

[novaderrik]

could be a harmonic thing, too.. nothing actually hitting, but the pipe is causing the exhaust pulses to make things vibrate.

 

[HouTX87]

I think you're right. That's what I'm thinking. I'll go ahead and check the down pipe clearance carefully anyway. Thanks guys.