ford f-150

Discussion in 'Other Repairs' started by fwmud, Nov 6, 2005.

  1. fwmud

    fwmud New Member

    Messages:
    693
    State:
    Wilson's Mills,nc
    I've got a 1998 f-150 that has the 4.6 gas engine in it.
    The problem I'm having is with the engine. It knocks terrible if ya use regular gas.
    Switching to high test totally cures it. If I run mid-grade it knocks a little when you punch it to enter traffic or to pass.
    Would a sparkplug change cure this?
    Or is this another of those dang car computer problems?
    The original owner ran only high test in it.
     
  2. Gator

    Gator New Member

    Messages:
    1,116
    State:
    Ludowici GA
    Keith look into the owners manual and see some of the motors will require High test and if it does not then have the computer chip checked
     

  3. whichrod

    whichrod New Member

    Messages:
    102
    State:
    columbia sc
    hi there here or some common causes if spark knocking improper ignition timing, combustion chamber deposits, improper EGR system operation, ignition system crossfire, a defective knock sensor


    fist thing i would do is take the egr off to see if its clogged
     
  4. cook

    cook New Member

    Messages:
    1,494
    State:
    Plattsburg,Mo.(near K.C.)
    Slipped timing belt/chain??
     
  5. fwmud

    fwmud New Member

    Messages:
    693
    State:
    Wilson's Mills,nc
    Thanks a lot for all the response.
    The manual does not say high test is required.
    Thanks again.
     
  6. quadman

    quadman New Member

    Messages:
    98
    State:
    Danville, Virginia
    Switch to a cooler burning plug.
     
  7. Gator

    Gator New Member

    Messages:
    1,116
    State:
    Ludowici GA
    Keith then try what Which rod post about the EGR and also try Quadman's idea because with out being able to put hands on it I would be hard pressed to say for sure.
     
  8. olefin

    olefin New Member

    Messages:
    3,908
    State:
    Texas
    Keith,

    No, it's not required. The 4.6 should run perfect on 87 octane.
    I bought a new 98 F-150. Drove it till this past spring, daughter has it now, it has never knocked.
    Sorry, no suggestions for your problem for I only replaced the battery on mine couple years ago.
     
  9. Phil Washburn

    Phil Washburn New Member

    Messages:
    7,680
    State:
    Shawnee OK
    it needs to be scanned, keith..sounds like some timing problems...not likely to be the knock sensor, but it is possible. the crank and cam signals may have a sync problem, or it could be the computer itself
     
  10. THE FISH WHISPER'ER

    THE FISH WHISPER'ER New Member

    Messages:
    95
    State:
    waynesville ,IL
    got a 99 with the 5.4 and it likes to rattle when it is not completly warm kinda anoying but it goes away and it is the runninest truck i ever had but i have a towing power chip in it also that might be part of the reason
     
  11. solomon

    solomon New Member

    Messages:
    735
    State:
    MS
    Keith, I have a 97 with the 4.6 and it knocks ever so slightly sometimes, and more noticable when I romp on it. I had it checked out because sometimes when you pull up to a stop it's got a light shake to the idle. Tech scanned it and said it was the EGR sensor.
     
  12. fwmud

    fwmud New Member

    Messages:
    693
    State:
    Wilson's Mills,nc
    I checked mt records,and I can't find hwere the EGR was ever replaced so I'll try that this weekend.
    Phil, can you re-do your post in "plumber-electrican" english?
    :rolleyes:
     
  13. jason454ci

    jason454ci Active Member

    Messages:
    1,307
    State:
    Zanesville, Ohi
    Keith does it have a check engine light on?
     
  14. solomon

    solomon New Member

    Messages:
    735
    State:
    MS
    Mine is. I still havn't replaced the EGR sensor yet. The check engine light stays on.
     
  15. fwmud

    fwmud New Member

    Messages:
    693
    State:
    Wilson's Mills,nc
    No check engine light is off and hasn't come on at all.
     
  16. jason454ci

    jason454ci Active Member

    Messages:
    1,307
    State:
    Zanesville, Ohi
    Those EGR pressure sensors are notorious for going bad. Not just on the trucks either. However the sensor itself will not cause a driveabilty problem. It will turn on the engine light. Now a bad EGR valve or solenoid will cause a problem.
     
  17. Phil Washburn

    Phil Washburn New Member

    Messages:
    7,680
    State:
    Shawnee OK
    keith, let me get back to you on this one ..i have a buddy that is good on fords, and he will be back in town tonite...i'll ask him about it
     
  18. Phil Washburn

    Phil Washburn New Member

    Messages:
    7,680
    State:
    Shawnee OK
    and keith, check and make sure it has the right plugs in it - that would be highly unusual for them to cause that prob, but it could contribute to it
     
  19. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    plumber/engrish translator

    If you take it to a shop, they will hook it to their computer thingy. The computer thing-a-ma-jig probably wont say that the knock sensor is the problem but it could. It is very possible that the crank and cam are working against each other or, it could just be the computer chip like thing in your truck went bad. More later after buddy who is a ford know it all comes home.
     
  20. Phil Washburn

    Phil Washburn New Member

    Messages:
    7,680
    State:
    Shawnee OK
    ROFL, tony...not bad

    keith i'd be glad to scan it for you if you'll bring it over - i don't make service calls :D