Se7ix

I am experiencing the following symptoms in a 94 z28 4l60e transmission with 111k original miles. The problem occurs constantly and is not intermittent. You could set a watch by it.

Symptoms
1. rhythmic pulsation and vibration occurs under light load at 48 – 60 mph: 1500 – 2000 rpm
2. acceleration (w/o causing downshift) eliminates pulsation and vibration
3. deceleration causes heavy vibration (complete release of throttle)
4. slight tap of brake pedal immediately stops vibration in deceleration
5. engine rpms fluctuate (bounce) in sync with the pulsation
6. surging at idle (intermittent) – have replaced plugs, wires, and coil – possibly opti but not that far yet.

Possible causes
1. torque converter – internal damage
2. torque converter – front bushing wear at crank mating surface (TSB 87-54 (Sept))
3. TCC solenoid – worn valve
4. PCS – malfunctioning causing poor pressure

Work done so far
1. replaced burnt fluid, filter, and pan gasket
2. 8oz SeaFoam-brand shudder solvent (non-leak stopping formula so won’t swell seals)


Any feedback is appreciated. I am continuing to gather information but so far, I am leaning toward distributor problems manifesting themselves in the high load, low rpm band. I say this only because I have other small ignition-related problems. My second guess is actual torque converter or flywheel problems.

Any knowlege is appreciated. Thanks everyone.

-John

flyinZ

Did u ever figure out what your problem is?

ShawnMacAnanny

Lmao what's with the old post? He hasnt been on since January of this year.

flyinZ

ya, ya..

I just did a search on a few symptoms, that my buddies car is havin' and I figured Id try to see if he fixed it or not....its not a big deal.

ShawnMacAnanny

To me it sounds like the locking mechanism to the torque converter is screwed up, and i think there is probably another problem not related causing his idle to be bad.