Knock At Idle

[rabt]

I'm new to the forums and i must say this looks to be the best place for 6.5 info. The Truck in my Sig. Knocks when idling at 650 -800 RPM's as soon as it revs past 800 - 900 its fine and the knock goes away .. I have Read some other post about crank pulley and Balancer they both seem to be ok .. I removed the belt to check the pulley and the noise is still there and the balancer seems to be in good shape .. Any other suggestions on what to check next??

[Patrick m.]

is it a faint knock, or a "no doubt about it" knock?

Different people will describe diesel engine noises very differently, some knocks, and rattles are of no concern.

If the knock is very pronounced, you may want to carefully loosen each injector fuel line untill engine is unsteady (fuel will leak from line causing injector to remain closed) do this on each injector untill the noise changes dramaticly,,,,,, then you have found the guilty cylinder.

you should also run a compression test, if all is good, have the injectors tested or replace them all.
If compression is not good, well you know.

take note of oil or coolant consumption, some oil useage is ok, about 2-3 qts between changes max.