V8 2wd auto transmission. I left work last night and the engine "I'm assuming" was shaking real bad. Pulled over, notice theres low oil so put in 2 quarts to bring it back to full and shaking persisted. If I'm at an idle it acts normal, only when I begin to move will the shaking start. If I ease off the gas while driving, no shaking. If I put it to neutral and coast there is no shaking. Only when the engine is under load I feel. No knocking in motor. I'm lost as to what it could be. Checked mounts, they seem fine. No leaks. Going to put it on blocks and test this weekend, just not sure where to start looking.

 

Note. It may not be engine shaking. But I feel strongly it is. Whole vehicle shakes and it feels like it's engine causing it

 

I suspect a drive shaft u-joint is bad and vibrating under load.

 

Check your transmission mount, My 97 ZJ is doing the same thing. Crawled underneath, inspected and found the rubber bushing in the transmission mount was shot. New one ordered through RockAuto and will be installed on arrival which should eliminate the problem. PS the part linked in the URL is for a 97 with a 4.0, yours might be different.

 

I say mounts also. low oil may be a red herring.