Any Idea?.....3406E Cat Problems

Discussion in 'Trucks [ Eighteen Wheelers ]' started by mapstransport05, Jan 21, 2008.

  1. mapstransport05

    mapstransport05 Bobtail Member

    Messages:
    8
    Thanks Received:
    0
    Joined:
    Jan 21, 2008
    Location:
    Dawsonville, GA
    My husband has a 3406E C-15 that was in an accident in May 2007 and has had problems every since. We cant figure out what is wrong!

    What it is doing: It lunges and lopes. It doesnt do it until it reaches operating temperature and it only does it on the foot feed. Not cruise control. Sometimes it acts as if it looses power and then sometimes it acts as if it gains power on its own, while holding the foot pedal steady.

    What we have done to try to fix it: We have put it on the dyno a couple dozen times to no avail. The first time it said #1 and #2 injectors were bad. So we replaced them and hooked it back up to the dyno and it still said #1 was bad so we swapped #1 & #2 and it still said it. So CAT told us it had to be the wiring harness from the ecm to the injectors, so we replaced that. Still not fixed. Then we were told that since it does it on the foot feed and not cruise that it was the throttle position sensor. So we replaced it and still not fixed! Then we were told it was the ECM so we replaced that and it worked for about a month with very minimal loping/lunging and then it started doing it really bad again. We noticed that the plug from the firewall to the ECM was cracked (probably from the wreck) and was told that if moisture got in there it would short it out and cause the problem, replaced that and still not FIXED! Running out of ideas and money, husband going bald, wife going insane Please help!
     
  2. MedicineMan

    MedicineMan Road Train Member

    Messages:
    5,792
    Thanks Received:
    6,400
    Joined:
    Jan 13, 2007
    Location:
    Woodville, TX
  3. mapstransport05

    mapstransport05 Bobtail Member

    Messages:
    8
    Thanks Received:
    0
    Joined:
    Jan 21, 2008
    Location:
    Dawsonville, GA
  4. RNGTransport

    RNGTransport Light Load Member

    Messages:
    134
    Thanks Received:
    19
    Joined:
    Jul 13, 2007
    Location:
    Allendale, MI
    Take it in one more time to CAT and had them diagnose the problem and fix it themselves. Thats all I can think of.
     
  5. mapstransport05

    mapstransport05 Bobtail Member

    Messages:
    8
    Thanks Received:
    0
    Joined:
    Jan 21, 2008
    Location:
    Dawsonville, GA
    The last 5 times we have taken it to Cat they have kept it for about a week each time and every time the walk away scratching their heads saying I dunno. Ready to junk it.
     
  6. Brickman

    Brickman Trucker Forum STAFF Staff Member

    Messages:
    12,921
    Thanks Received:
    12,093
    Joined:
    Sep 17, 2006
    Location:
    WY
    Its clearly an electrical problem. I HATE electrical problems because they can be near impossible to trace down.
     
  7. RNGTransport

    RNGTransport Light Load Member

    Messages:
    134
    Thanks Received:
    19
    Joined:
    Jul 13, 2007
    Location:
    Allendale, MI
    If thats the case I would not have paid for the service if its not fixing the problem. Next bet is try taking it to another CAT service shop or deisel shop in general.
     
  8. Brickman

    Brickman Trucker Forum STAFF Staff Member

    Messages:
    12,921
    Thanks Received:
    12,093
    Joined:
    Sep 17, 2006
    Location:
    WY


    Good suggestion.
     
  9. mapstransport05

    mapstransport05 Bobtail Member

    Messages:
    8
    Thanks Received:
    0
    Joined:
    Jan 21, 2008
    Location:
    Dawsonville, GA
    we took it to a general diesel mechanic last week and he thinks it is the air to air box havent replaced it yet. Just mulling it over right now. We have taken it to 3 different CAT shops and the one diesel mechanic. Any and all suggestions are greatly appreciated. Does any one think that it has to do with the accident or just pure coincidence?
     
  10. Brickman

    Brickman Trucker Forum STAFF Staff Member

    Messages:
    12,921
    Thanks Received:
    12,093
    Joined:
    Sep 17, 2006
    Location:
    WY




    I wonder why the air to air would cause a lope with the foot feed but not the cruise.
     
Draft saved Draft deleted