I feel a bit silly asking this, but after being engrained with the sound of the stock Cummins over the past 70k, it's bugging me.

98.5, manual, 70k, all stock with gauges - DD2s added this weekend. Directly after the install of the injectors, I got an apparent ticking noise at idle (perhaps just off boost). I wouldn't call the ticking high frequency, but it's higher than the average rattles and noticable. Is this normal? Perhaps related to the additional fueling at idle? I followed install instructions to the "T". Retainers torqued to spec, etc. Heck I even pulled the cover to inspect and re-check torque after 20 miles. I tried to isolate with the old 3/8 extension to the thumb to the ear thing and it doesn't appear to be coming from the VP, valvetrain, or any particular injector tube. It's most clearly heard from under the truck. The idles like stock and pulls considerably harder. I consider myself a pretty avid "weekend wrench", but the whole cause and effect of mods on diesels is new to me. Any ideas or suggestions? Thanks!

 

No visible leaks? Some of the 98.5's needed connector tube replacements. Im sure you checked the connector tube engine serial number, but thought I would mention it.

Ticking is not normal if it never did it before.

If anything the idle should smooth right up and the engine run quieter and smoother.

Don~

 

No visible leaks, no smell of diesel under the hood. I did check the serial number for the injector tube replacement and though I don't recall the number off of the top of my head; it's considerably past the cut-off number. Thanks for your Reply Don.

 

Don,
What is it about the connector tubes that ticks? The joint at the injector or at the line? I've got a tick that's driving me nuts and about to replace the injector pump to try to eliminate it. I'd rather replace the connector tubes.

If they leak, there wouldn't there be "extra" oil in the oil pan because these galleys are sealed to the back of the head, right?

 

Pulled connector tubes last night. No signs of leaks, holes, scars at mating surfaces, and when rolled, they appear to be straight.

crashinaz, when you get an extra 1-1/2 hours to kill, try loosening everything, pull the clamp off the top of the injectors and rotate/wiggle the injector as you snug the line outside the head back up by hand. Re-assemble injector clamps and finish tightening injector lines.

While you've got it apart, maybe pull each connector tube and see if there's something at the mating surfaces keeping it from sealing tight. Don't forget to oil the o-ring befor re-installing the tubes if you pull them.