Yeah exhaust brakes are not coming on at all whenever it is in cruise!

 

wait a minute, coughing sound? Is this when you go to downshift, and back off the throttle?

Try rolling off the throttle instead of snapping it shut, or if its on the cruise put your foot on the throttle half way, then hit the clutch with the other foot.

You're going from a massive positive pressure in the exhaust manifold to a negative one, and it's making that sound.

There's nothing wrong with the truck with this problem.

 

I wish it was that simple! :shock: When the R's get down there it is because I am trying to get down to a shift point and I still have my foot in the throttle. There is no change in anything I do when this happens. The only time this happens is when I am going up hill (or about to crest a hill), the R's are low, and the engine is under load. That is the only time it happens!

Thanks for the suggestion though!

 

Dan, sounds like your turbo could be on the way out. All of what you explain with power issues would cause what is happening to you.

 

1000,1200 Revs... Way too low for anything other than flat ground, not much wieght, no wind... Gese... I wiegh 125- 140,000 lbs, Get your revs up and keep them up, the other issues are c.p.u. settings. The low idle could be a cold engine paramiter .... ?

 

Found out that I was driving the truck as if it had a Detroit 60 Series in it and was actually lugging the engine. I now run it from 1400-1800 and have not had as many issues.