A new service calibration for the powertrain control module was released to address a sag condition, as well as others. I recommend receiving this calibration from the dealer. There are any number of internal transmission problems that could be related to this concern, as well as engine mechanical problems or ignition related problems (spark plugs) that could cause this condition.
There are several things that can cause your 1989 Oldsmobile to hesitate. Dirty fuel injectors are the most common cause.
cracked or broken wiring, blown fuse
not near enough cause i don,t own one
low trans fluid level.
you have to be more specific for a proper answer... at what speed does it shake?.... 40mph> ? what do you mean mist?
If there are no visible leaks....a blown head gasket.
if it smells like antifreeze inside the cockpit then your problem is the heatercore, since you can't see it.
It will, if it causes the fuel mixture to be out of range.
Expect 26 city, 34 highway in realworld. EPA estimates and different driving styles may cause variation.
dead battery, blown fusable link, severely cracked or corroded cables. especially check battery ground to chassis and engine.
Check for a busted engine or tranny mount.
if you have overdrive in that car it means that your about to go into overdrive