928mac

Ok, but from the way it was sitting on the stands, it is not related to that. It may be from sitting and something drying out. I would put a hundred k on it and see if it gets better or worse. It may help to pinpoint it.

I would guess it is a trans alignment or TT bearing. The trans may have settled from hanging.

Imo000

One or both of the transmission mounts broke? OR it's missfiring on one cylinder when under load.

the flyin' scotsman

Thought that too Sean but I checked xmember clearance and the engine does rock when blipped.

928mac

BTW mine vibrated until the suspension settled. don't no why. I assume old rear suspension, old on the car as well

James Bailey

If it ONLY does it under load unhooking moving back the TT is not going to prove anything since there is no way to load the engine....

the flyin' scotsman

t did cross my mind that theres a misfire..........wonder if one of the new injectors is ????

idle is smooth though.....rock smooth and it pulls to red line in 1st an 2nd and gettin there in 3rd

Mrmerlin

you could also inspect your work check
the power steering lines that come off the pump you may have tightened the hard line so it is hitting on the fenderwell this is visible from underneath the car
also inspect the motor mounts and their heat shields,
as well as the exhaust system and heat shields.
inspect the trans mounts as well ,
put a jack under the trans and lift it up a bit not more than an inch and use a block of wood.
Also inspect the bell housing bolts.
Check the trans cooler lines where the cross over the cats and run on top of the heat shield if the MMs are sagging then the lines can contact the top of the heatshield (not good)
this will require removal of the exhaust and center heatshield to reposition the lines to the 4 O clock position

the flyin' scotsman

ill add that the vibration is quite bad if I leave the engine right at 3k..............soon as I slow down or get to higher rpm the vibes are gone.

928mac

I didn't want to suggest it thats why I asked what you thought, but it sounds like you may have an engine miss.
Mine is also doing this when I have it to rich or lean well playing with the Tec-4GT.
Only you know what you installed buddy and it wouldn't be the first time a new part gave problems.

I do not know how you will check for an injector miss under load without a scope.
The way I use to check on my 1/4 mile car was I touched the header pipes, the one that didn't brand my finger, was missing.
Got a temp gun

the flyin' scotsman

I do have a temp gun and I can pull the fuel rail covers and double check conections.

Pull the plugs and check for correct gap...reset the plug and coil wires.

Release the flex plate pinch bolt.

All shall be done tomorrow and Ill report back

928mac

Good luck buddy, I hope it is something simple.
BTW, from what I saw, you do top notch work.

Brad

JoeTaylor

I had the same problem, the car would vibrate at around 3k RPM like being inside a washer machine on spin cycle. I thought is was a bad motor mount, but when I got it checked out at the shop, it turned out to be the torque tube bearings/damper. I bought a rebuilt torque tube with Super Bearings from Constantine and everything is as smooth as can be now.

My 1988 S4 is an automatic, the OEM torque tube setup is with two bearings and a dampner. Contantine did a 3 bearing torque tube, like whats used in 5-speed versions and eliminated the need for the dampner completely.

Good luck,
Joe

heinrich

Malcolm, my $$ is on tt damper/bearing.

the flyin' scotsman

The flex plate moved approx 4mm and there was a solid crank movement when I pried rearward on the flywheel.

Everything else is good, now for a drive

Randy V

Perhaps H put enough $$ there to get a new TT.