Are you referring to "wet stacking"?
I've only really heard of problems arising from people idling for long periods of times (full shift, dozens of hours or even days at a time) or turning up the fuel mixture too rich, or having leaky injectors. Any of these are what will cause soot to build up due to excess/ unburned fuel.
You work yours plenty, sounds like
I've only really heard of problems arising from people idling for long periods of times (full shift, dozens of hours or even days at a time) or turning up the fuel mixture too rich, or having leaky injectors. Any of these are what will cause soot to build up due to excess/ unburned fuel.
You work yours plenty, sounds like