Under load my truck makes a tapping/knocking sound at 1800 to 2000 RPMs. The load could be no more than the truck going up a hill solo, but is louder with a heavier load. If the engine was a gasser I would swear that I had a lifter going.


I've changed fuel filters, fuel stations, with and without additives and it makes no difference. It does seem to be worse when the outside temps are hot.


Just a note, my fuel mileage has not dropped at all (20+) and the engine feels as strong as ever!


Any suggestiions would be greatly appreciated?


Thanks,


MaxRock

hi maxrock..you know its funny because i have the same problem as you..i took mine three time to the shop and the adjusted the valve s and retight the fly wheel bolts,re adjusted the valves the secound time. and it's still the same...they told me that it was normal..but mine also does it during idle.does yours?..if you take it in make sure they tight all the bolts...i almost lost my starter during my lincoln city trip.mine also shakes a bit during idle which is driving me nuts!!

I have the same noise at 1800-2000 rpms. I remember reading a service bulletin about this. Basically it said that every engine is a little different and if there is a slight knocking noise aroudn 2000 rpm, there is nothing that can be done. They also said this does NOT appear to be an indicator of excessive wear or a failure.

Sorry to tell you this guys but mine did the EXCACT same thing and I had been having flywheel problems (manual transmission) so they pawned it off on that. This had been going on for quite some time till an injector failed and flooded my crankcase with diesel fuel. It was my guess that one (or more) injectors was not atomizing correctly and putting more of a droplet of fuel in the cylinder which caused the "knocking" sensation you are experiencing.....Then it failed all together and flooded the cylinder, bypassing the rings, and into the crankcase. They replaced all of the injectors but can't explain to me why my oil pressure is 25% lower and oil comsumption is over 1 quart per 3000 miles when before I brouhgt it to the shop is never used any oil.....I can figure out the answer to those questions and they wont do anything about it.

mwhitfil, Did your knocking noise quit after they installed new injectors?

Are you all sure your not confusing the point where your pilot injection cuts out. Ask the Tech's!

Are you all sure your not confusing the point where your pilot injection cuts out. Ask the Tech's!


Pilot injection cuts out at a lot higher of an RPM then what he is talking about. Do not think that is the problem. But based on what he is hearing, I might think injectors...

Yes my truck stopped all the knocking after the "rebuilt" injectors were installed and now I have a new and improved Dual Mass Flywheel and my truck drives a new one. I am happy again (for the time being)

Tell me more about this pilot injection. I have a change in "tone" at higher rpm's I shift at 1900-2100 and very very rarely go higher than that till 6th gear then at 2500 or higher I can hear a different noise....maybe what you are talking about.