3406E Ticking

I never saw this on a 3406 but a worn exhaust cam lobe can prevent exhaust from escaping properly. Then when the intake opens the pressure in cylinder pops out the intake. So yes a valve train problem can cause this.

 

I also hope that is not your problem that is just what came to mind for one problem that could cause all of your problems. I would look under the cover it could just be a loose adjusting screw, jake issue or something.

 

I broke an exhaust rocker arm on my 3406e once. It was while decelerating up an off ramp empty, no jake brake on. It was all of a sudden a very loud tick, it would puff the intake boots each power stroke of the engine since the exhaust or whatever it would be would come back through the intake. I only drove it the couple remaining miles home though before I took it apart. The rocker broke cleanly, cam and valve bridges were fine

 

It sounds like a loose valve or injector, as to why it is loose will determine how many meals of beans and rice you will have to eat to fix it.

If you just did the head then it is likely that one of the adjusters was not locked tight after the rack was run, if you run the rack again VERY soon you can dodge a bullet.

If the cam is going flat on a lobe then running the rack will correct the issue for short time but it will return as the cam lobe continues to grind itself away.

Good luck, here's hoping you just have a loose adjuster

 

Not necessarily they may be close enough,but if it runs rough cat may change the trim codes in the loaner ecm.

 

If you have a loose rocker it will still "look ordinary", you have to manually rotate the engine and check each one when it is off the cam lobe to see if the lash (or preload in the case of an injector) is too loose. Cat will not mess with the computer when they run the rack, that will come later if running the rack does not cure the problem or reveal the failure of a hard part. If it is missing you need to run a cylinder cutout test to narrow down which hole; that will save a lot of experimentation and guesswork.

Running rough and ticking sounds a lot like an injector lobe or rocker failure.