Knocking Noise from the motor........ PLEASE HELP!

[Tanker 06]

I have a 1999 f-250 with 167,000. i recently just changed the oil n fuel filter. made a trip of 300 miles and got home and noticed that it has a knock at idle. truck doesnt run rough, doesnt smoke. have good oil pressure and plenty of oil. throwing no codes well atleast the CEL isn't on. the knock seems to get louder once the motor is warm. seems to go away upon higher RPM. please help just wondering if it is injector, rods, valves, or maybe rockers. INFO APPRECIATED.

[Tanker 06]

bump guys come on i know there are some good mechanics that work on these thinks everyday i need help startin to lean toward injectors or injector but i just want some info and help. thanks

[rscott]

Hey Guys help him out I got the same problem with my 97' 7.3 D.I. but a little worse, sounds like marbles in a coffee can or a starter/bendix ridin against flywheel.

[Tanker 06]

Bump once again, someone help me please

[canister]

BUMP. Having a similar issue.

[dray8165]

The marbles in a coffee can is a typical way that a torque converter sounds on its way out.

Listen to this video - does this sound like anybody's truck?

YouTube - greysmoke.MOV

An injector causing noise is also going to cause smoke. A bent pushrod will sound similar, but without the smoke.

[rscott]

Thanks for the info but after pulling tranny and verifying all good we chased this another week removing & replacing external moving parts to eliminate possibilities. What we eventually found is that the FPR screens were 70% blocked and some injectors dry firing sending noise down thru crank and giving a very similar sound but at a faster grinding. It is really amazing that this fixed the problem and more amazing that it created this kind of noise. Thanks again for all the info to keep fuel pressure in mind - of course with the type of noise, it was the last thing I checked. I've learned the hard way to stick to the basics 1st ! Thanks again

[GreenF350]

Hmm...Where is this screen? I may be starting to have an issue with this myself. Not quite as severe though. Sounds like it is worth me looking into.
-Aaron

[BKraft03'7.3L]

I'm also very interested!! My truck has been doing this for a while. changed the fuel filter and found alot if crap in the bowl. My screen maybe clogging as well.

[rscott]

Just posted response for Aaron, but if you found a lot of sludge in your fuel bowl be sure to pull the plate that the filter sets down on and see what you have built up under it (if you haven't already), mine was about 2" deep with crap under the elevated bottom plate.