1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Ford 7.8 liter diesel knocking

Discussion in 'Truck & Equipment Repair' started by roofer, Oct 10, 2007.

  1. roofer

    roofer Junior Member
    Messages: 1

    Looking to purchase a repair manuel for my dump truck. It has starting knocking at 2000-2500 RPMs and now has starting smoking too. Any suggestions would be appreciated.
  2. clark lawn

    clark lawn PlowSite.com Addict
    from NE ohio
    Messages: 1,233

    what color is the smoke? a miss in a diesel will sound like a knock. If you dont know much about diesels you should take it in some where they may be able to put it on a computer and find out whats up.
  3. mrbrickman

    mrbrickman Senior Member
    from montana
    Messages: 138

    yeah put that 7.8 on a computer hahahahahah

    could be an injector, is it a steady knock? does it fluctuate with the engine rpm?

    usually you can tell if its top end or bottom end by sound

    id do some injector troubleshootin first

    find a way to undo fuel to each injector see if the noises change

    black smoke you may have a bearing on a connecting rod going which will make the knock and break a ring.....break your crank...

    grey smoke is an injection problem