Before you say anything smart, I know it's a diesel, it shakes.

However, today I started it after a 5 hr soak.
45 seconds after start, I flipped on my 1,400 RPM SEIC so I could get the cab cooled off for passengers.
The whole truck started shaking and it seemed to have trouble getting up to the set 1,400 RPM. Took about double the time is normally takes for SEIC to rev up the motor.
Strong smell of exhaust but nothing I could see.

It's 70 degrees F outside.
Coolant is at max fill line running.
Oil is slightly above max fill line (thank you regen); checked before start.
No leakes while running.
Oil dipstick properly sealed.

Reminded me of a cold 6.0L.
Anything I need to check for?
It never did anything like this when it was 8 degrees F over the winter.
Seems it should be happy with 70 degrees F.

 

EGR valve sticking. That is what comes to mind.