Hey guys, my truck has been displaying some engine problems. When allowing the truck to slow down naturally, the exhaust sounds like what could only be described as semi truck engine braking. It's no where near as loud, but it's definitely the same sound. One of my buddies who is a diesel mechanic said it could be the cam phaser and he also said something about valve overlap if I remember correctly. Any ideas?

 

Err.. what I should say... IS he right or am I totally lost here?

 

I have an 07' 5.4, & love the sound of the Jake Brake.

When you figure out how you did it, let me know!