One of the causes for a diesel noise is a cam timing gear bolt thats not seated completely. There were occasionally a few issues where the cams were not drilled/tapped deep enough and the cam gear retaining bolt would achieve the correct torque but not completely tighten leaving the washer loose. This would allow the washer to wobble just enough to make a diesel noise. May or may not be the reason for your noise but its fairly easy to check. A collapsed/weak lash adjuster will allow the follwer to flop around and sound like a marble in a can type noise. Also easy to find once the cam cover is removed. Good luck.

 

is there any recommended action for piston slap?

 

Drive it till it drops.

 

Does this condition decrease the life of the engine?

I guess what I'm asking is - should I unload the thing or just keep it?

I really like the truck, other than the noise

 

Not the Cam Phaser at all. I want to say up front that we could not have asked for any better service than we received from our dealership service department. They even rented us a car and our truck is out of warranty. Granted we paid for a cam phaser replacement but we got that at a discount.

After installing a cam phaser which did not fix the clicking problem they actually took the engine apart and did not find anything. The service manager finally went with his gut feeling and replaced the exhaust manifold and there is no more clicking. It seems they orignally checked that but there was no sign of carbon leakage and after the engine warmed the leak sealed. Just glad it is fixed.