engine / trans VIBRATION

[SuberNatural]

Ok, first i will explain what i have done to try and track it down so far.

1. pulled each fuel injector individually to check for a miss. Engine is not missing.
2. replaced a bad trans mount with a Urethane filled mount from YT.
-----obviously made the vibration much worse being that it wasnt the sole cause nor the solution lol. But its been overdue.
3. changed all of the spark plugs with NGK Iridiums.
4. visually inspected all 6 coil pack. No tears, rips, etc anywhere.

Road tested to track down conditions
- driving at highway speed even throttle it isn't super noticeable
-idle is fairly smooth and around 600-650 rpms
-heavy acceleration the vibration is more severe and becomes a droaning noise in the higher RPM's (4k + )
-in park and neutral the vibration is present when revved out of idle. most niticeable around 1.5-2.5k RPMs, but still present 2.5k+ RPMs.

Would like to add that the trans has about 65k miles on it. I have installed an ext filter and a cooler in series with the transmission. ATF recently (about 5k miles ago) changed out. Had front diff fluid inspected (looked good). The trans fluid looks good and smells good (not that i like the smell of hydraulic fluid).

The flexplate has been suggested so far, but I have no real info on anything specific.


Thanks in advance!
_Mike

[SuberNatural]

Anyone have anything on this?

[Manarius]

Engine mounts?

I was thinking driveshaft U-Joint but you said it vibrates even in park.

[stiguy]

you running 85 fuel?

[SVXRide]

any recent exhaust system work?
-Bill

[kwren]

Any codes?