WOT getting onto the highway. I shifted around 3,000 RPM. I've never done that before and it blew a good size black cloud out the tail pipe during the shift. After that, the truck ran great. I think it was in need of that. I've never gone above 2500 RPM and 99% of the time shift just below or just above 2000 RPM.

Is the black cloud just unburnt fuel and soot? I kept into it cruising at around 80mph for a couple of minutes after that and there wasn't any smoke coming out. I had to open up my '69 Benz diesel once and a while to clear it out. Does the same go for these trucks? I figured because it's a newer diesel, it doesn't need that.

 

Yeah, it's just a normal function of suddenly changing RPMs. I don't think they need it as much as the older ones, but I think they still need it now & again.

 

May have been a little of both. It is normal for it to puff a little smoke at WOT some trucks more than others depending on mods and tuning.It may not be necessary but it is fun to go WOT some times

 

Without a doubt it ran significantly better after that. Smoother throttle response for sure.

 

getting it good and warmed up. i try to do that about once a week. then i feel guilty, but not for long!

 

If you do alot of intown driving, its good to get it out on the highway and blow it out. I used to take my grandmoms car(gas) out on the highway and mash on it and man the smoke but boy did it run better afterwards.

 

That's right, you have to let them run every once and a while.

 

When I was a valet in college we used to offer this service on select vehicles ...you could always tell who really drove their cars and who didn't.

 

It's called an "Italian Tune-up" in my neck of the woods.

 

That's what the Mercedes Benz diesel guys call it too.

 

I do a lot of in-town driving and I have noticed this as well.

Clearin out the cobwebs.

 

maybe not in desperate need of it, but it sure is fun to look out and see nothing but black smoke. Now if you were to get a DP it would even be more fun