I have a dodge ram 3500 -03 with a cummins diesel.
The problem is when i drive slowly i can smell oil smoke in cabin.
What is the problem?

 

you are driving too slowly....

no clue, free bump.

 

Are you sure it is oil burning or is it exhaust fumes? If it is exhaust, you might have an exhaust leak. If it is oil, you have oil dripping on the exhaust somewhere. Oil usually won't burn unless it is hitting something pretty hot, like the exhaust. Most likely place is the valve covers leaking on to the exhaust manifolds. Hope this helps.