99 f350 4x4. Early 99 chassis with a late 99 engine.

While parked and idling high at 1100 rpm the engine shakes the truck quite a bit. If I go above or below 1100 it goes away...

Is this normal?

 

Not normal.
Does your engine shake when trying to accelerate from 45-60 mph in top gear as well?

 

Nope it does not... only shakes like that when idling at 1100...

however when it's cold outside it auto idles up to around 1100 and does not do it. But if I'm parked and step on the gas to raise the RPMs to 1100 that is when it shakes.

 

my truck did the same thing at 1100 rpm until I replaced the injectors.
Now it's smooth.

 

Ugh oh... How much did that cost??

 

Both Mine and my dads truck have a tiny bit of the 1100 shake. Slight but noticeable once you know that it is there. Mine has slight bit more that my dads..