Hello all-

Ive tried searching the 12 pages of "engine tapping" threads and Im still a little confused on this one. I dont have any tapping sounds at idle at any temperature. I dont seem to have any tapping sounds under hard to moderate acceleration (under boost). Its there once the truck gets up to cruising speed, at any speed and rpm. Im stumped everything runs good but the noise has just showed up within the last 2000 miles. Ive done the valve adjustment and no change. To me it sounds exactly like a noisy lifter or rocker arm a gas engine.

Thanks

 

Believe it's a timing issue. Mine does the same. Like around 2K RPM it sounds like one lifter quietly ticking. Try switching the timing on your Smarty and see if it changes. After I programmed my truck it got better but still there when cruising with a light pedal. With a stick, I accelerate and roll out of the throttle before I shift and it'll clatter a little as it falls through the boost table. The fueling rate, and I think injection timing, changes as the boost falls off.

 

Thanks Captain Kelley Ill mess around with it some see if it chages.

 

I have the exact same thing on mine. Runs great, havn't had any problems with it, and it happens exactly when you say yours does. I've messed with the timing and no change. I've just learned to live with it. Ive ridden in a few other crs that do the same thing so I dono. Maybe its normal