rough idle ,vibration

I have a 1991 s10 Blazer 4x4 with a 4.3 v6. My problem is that it has a very rough idle and the whole engine shakes. Also when I am driving it ,it has a vibration that I feel mainly at my feet. The vibration gets worse as it changes gears and is at it's worse in overdrive. It has a 700r4 automatic. Does anybody have any ideas.

Thanks, Ddum8
P.S. Go Jr.

Sounds like engine mount, my 97 saturn had the same exact problem, weird thing was I could put it in neutral at a stop light and vibration went away, I thought I had MAJOR tranny problems, dealer replaced the upper mount and drove like brand new!

I really doubt that the rough idle is being caused by a bad motor mount, although anything is possible. I would start with a basic tune-up, including spark plug wires, plugs, distributor cap and rotor, and check the timing. If that doesn't do it, let us know.

"whole engine shakes" um, that is what the engine mounts stops.

But what is causing the rough idle to start with? I have had broken motor mounts on many different vehicles and the engine purrs like a kitten. The way the broken mount was discovered was when the engine raises off the broken mount and the fan chews up the shroud. I am not saying that it isn't a possibility, I am saying that there are possibly multiple issues here.

I have a 1991 s10 Blazer 4x4 with a 4.3 v6. My problem is that it has a very rough idle and the whole engine shakes. Also when I am driving it ,it has a vibration that I feel mainly at my feet. The vibration gets worse as it changes gears and is at it's worse in overdrive. It has a 700r4 automatic. Does anybody have any ideas.

Thanks, Ddum8
P.S. Go Jr.

Have you ever done a tuneup?

Fuel Filter
Air Filter
Plugs
Cap & Rotor
Wires

Any check engine lights?