i have a 96 olds 88 and about 2 weeks ago i could feel a vibration while idling. while driving the vibration got worse. then last weekend i noticed what i thought was a misfire while driving. it started on the freeway going about 70 in overdrive. when i accelerated it stopped. it did it again when i stopped accelerating and was driving at a constant speed. i replaced the plugs and wires a few months back and cleaned the MAF the other day. the fuel injectors are at normal ohms also. i've had it on 2 different diagnostic machines and they both didn't show and misfire or codes. has anyone else had this problem?

Test your coils.

i just tested my coils. when i tested the primaries one of them was reading from .3 to .8 ohms. it was all over the place and wasn't giving me a constant reading. i'm gonna replace it and hopefully that will solve my problem

Kind of sounds like you have a issue there. Willing to bet if you heat it up it will fail.

i replaced the coil pack and went for a test drive. the surging/hesitation didn't happen. i think that problem is solved. but the engine vibration is still there. any ideas on what that could be?

Does the vibration follow engine RPM, or the speed of the car?

the speed of the car. when it'* idling you can feel it then when i shift into gear it'* vibrates harder. i feel it in the streeting wheel and on the accelerator while driving and when it locks into overdrive it seems to be worse. i'm begining to wonder if the cluch plates are slipping. i'm thinking of changing my tranny fluid and filter and see if that helps

Check for play in the axles.