Hey wanted to know if anyone had any insight on a Vibration that is engine related at 3k rpm. See my sig for my mods, but I did notice a vibration there before I TC'd. It was hardly noticable, other than it would make my sunroof vibrate a little. Now with the TC its out of control, everything shakes, dash sunroof steering wheel & etc. Its fine below 3k or above 3.1k then its smooth, no vibrations at all. This is very annoying due to the fact that most of the time when your cruising around town, you are around 3k or you need to run through it as your shifting gears. Any insight would be swell!

Thanks...

 

your exhaust shields. They could be loose and resonating. Also check the actual exhaust if your havent already! or maybe one of your engine mounts? hope this at least helps!

Cheers,
Jonathan

 

yeah +1 for checking all mounts, especially trans mount.

 

Just a guess, but looking at your dyno graph from your other post [it's very awesome of you to do that, btw!], you're running obviously leaner at exactly 3k rpm [though, it seems you're only between 13 and 14:1 and this should be ok?!?!?], so perhaps that is the root of your vibration. If that IS the source of the vibration, that's a very BAD thing, you know...rough running engines like to die . Below, I'll post the graph again...



Otherwise, I used to notice vibration through the steering wheel under hard acceleration with only 200 or so whp in my car, when my alignment was kinda bad. That went away, of course, with alignment. How are you feeling this vibration? Through the chassis or the steering column?

Good luck, either way! Nice work.

 

On the exhaust....I removed the header & downpipe & wrap'd them up with exhaust wrap to help. I put back together & made sure everything was tight. So I know I am decent there, but i will go back over it since i ran like 9 runs on the dyno yesterday. There are currently no exhaust shields in the engine bay, just underneath the car. It couldnt be a loose engine mount...i will look into that..

The vibration is felt and heard throughout the entire car. When on the dyno I didnt hear it so much, but i was outside the car.

As for the lean spot, we just couldnt tune it out, that is right before the turbo spools, which kind of makes no sense, as it should be richer. Its defintely an engine vibration, but it could be normal, but just more exagerated from the 3" downpipe. I really want to get this knocked out, as its horrible to drive at 3k!