Need help -very annoying vibration in 2004 SLE

[olblueeyesbonne]

Anyone ever run into this before -I just put a motor in a 2004 Bonneville SLE (3800 non-sc). The car had a horrible vibration before the swap, as if all the engine/trans mounts were solid poly mounts or were totally shot. Put the new motor in, a new Precision torque converter, replaced the torn front mount, and checked all the other mounts, and exhaust clearance from manifold to exhaust tips and everything looks perfect.
The car still has the same horrible vibration throughout the chassis -you can feel it in the seat, steering wheel, and pedals.
We took the torque converter bolts out to rule out the trans and started the engine and it still didn't change one bit. All the torque converter and flywheel bolts are good, two different motors (both with good harmonic balancers, and not one thing changed.
We checked all the cradle bolts and bushings and they seemed to be fine.
Car was in a previous front end wreck, but the only tell-tale signs I saw were the painted drivers airbag and the airbag light on -replaced the airbag module and no more light.

Anyone who has any idea's please call/text me @ 320-290-1217 or email me @ theupnorthshoppe@gmail.com

Thanks in advance,
Martin

[olblueeyesbonne]

TTT

[ramirez32385]

hey! i got a 2000 bonneville from my sister in law and it also has a vibration when it sits in park and when you take off with it. i also replaced the front engine mount and still have a vibration. im gonnna check the back mount but overall i dont know what causes the vibration. i also feel that the engine was changed once in its life. i feel the trans as the vibration causer but overall i feel it shifts fine. let me know what you find

[olblueeyesbonne]

Andrew stopped in and checked it out and realized it had the wrong rear exhaust manifold on it -we had swapped the rear manifold from the motor we had pulled out, but hadn't realized it was a replacement motor out of a w-body.
Got that swapped out today.
THE CAR STILL FREAKING WANTS TO CRUMBLE BECAUSE IT SHAKES SOOOOO *dang* BAD!!!
Sorry, yes, it's that frustrating and the customer won't come for it until we have it fixed.

[crash93ssei]

Was anything off the original engine used on this one? Injectors, flex plate etc....?

[redzmonte]

flex plate etc....?

That was my 1st thought.

[olblueeyesbonne]

Oil pan, oil filter adapter, oxygen sensor from motor we removed.
Flex plate came with new motor.
New front boat roller trans mount, rear trans mount is recent replacement and in new condition.
Engine and trans side mounts have been checked and visually/compression/expansion tested and passed all tests.
Cradle bushings all appear to be in good shape.
With correct rear exhaust manifold in place the exhaust hangs freely (no unnecessary tension on any hangars).
Started car with exhaust disconnected to rule out plugged cat.