3406E keeps scoring pistons

Discussion in 'Trucks [ Eighteen Wheelers ]' started by MARK AT PIMCO TRANS, Apr 16, 2012.

  1. MARK AT PIMCO TRANS

    MARK AT PIMCO TRANS Bobtail Member

    19
    8
    Dec 27, 2011
    SAN ANGELO,TX
    0
    Have a 99 Pete 379 with 3406E ESN#1LW32335. Truck has 1.8 million miles. About 100k ago the original crank broke in half. Failure was credited to harmonic balancer. Crank was replaced along with liners/pistons, balancer, reman Cat head, 6 new injectors, new oil pump, oil cooler, radiator, new bearings, etc. After first 55k #2piston scored. Installed new #2 cylinder pack, inspected and replaced oil cooling jet, replaced oil cooler. Around this time a fuel driver in the ECM took a dump so it has a new ECM as well. Last week #4 piston scored. Replaced all remaining cylinder packs same routine. Last weekend got towed in again and has scored another piston. It is getting torn down right now dont know which cylinder, but none have any real milage on them. All genuine cat cylinder packs and injectors. Have several old Cats in fleet and have never had such a problem. Any help or experience with similar situation is greatly appreciated. If this thing gets towed in again I'm going to shoot myself. Thanks. -Mark
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. Superhauler

    Superhauler TEACHER OF MEN

    12,209
    100,703
    Jan 30, 2010
    keep stroking.
    0
    did they mix up the jets when it was over hauled? they are directional. pluged oil supply for jets? or dumping to much fuel in it? ie bigger injectors than normal. thats all i can think of. one more thing didnt happen to code the injectors with a marine code-5232 or 6999.
     
    Last edited: Apr 16, 2012
    MARK AT PIMCO TRANS Thanks this.
  4. MARK AT PIMCO TRANS

    MARK AT PIMCO TRANS Bobtail Member

    19
    8
    Dec 27, 2011
    SAN ANGELO,TX
    0
    We have performed all work inhouse. Not that I'm above owning up to fouling something up. All jets and passages looked fine. That was the first thing I thought of also. Injectors are stock from CAT. ECM did receive a tune from a reputable vendor (who will remain nameless to avoid pissing contest and has done fine work for us on other vehicles with no problems) to increase fuel economy. #2 cylinder scored before ECM crapped out. Weirdest thing is vehicle has NO driveability concearns. Both times just starts rapidly sucking in and blowing out engine oil when she goes. Both times all other pistons/liners look great. Thanks for the help. -Mark
     
    moonshine powered Thanks this.
  5. truckmechanic

    truckmechanic Medium Load Member

    534
    140
    Jan 14, 2012
    Hi Desert Ca
    0
    Had a cummins doing the exact same thing the mechanic the used to work here just kept putting pistons in it it two broke a crank after 5 pistons I got stuck with it turned out to have little chunks of iron from the broken crank inside the oil galleys oil cooler and filter head pulled the block had it hot ranked put it back together and hasent been back since the old mechaninc never cleaned up anything pulled engine replaced crank slapped it back together just a thought
     
    MARK AT PIMCO TRANS Thanks this.
  6. Mr. Haney

    Mr. Haney Road Train Member

    2,693
    2,020
    Dec 17, 2008
    0
    You may want to get a cylinder bore gauge and check the liners for roundness. A cylinder pack that has been mishandle will score, but usually takes some time for it to show up, but it will eventually, usually after a hard pull.

    You may also want to make sure the water pump is moving the correct amount of coolant. CAT has had in the past a problem with the impeller slipping on the shaft.

    If the injectors are defaulted to a supposed hot trim number in the ECM.......program the correct injector calibration codes from each injector into the ECM. CAT Reman injectors with defaulted injector calibration codes(trim numbers) can be as much as 20% difference in flow across the 6 cylinders. This creates a hot cylinder, but never shows up as high EGT's or coolant temperatures on the gauges, because the other 5 are hiding it by mixing the coolant and exhaust gases before the gauges sending unit. If it is a hot injector doing it on one cylinder each time...........are you paying attention to where you install them or do you throw them in nilly willy because they're defaulted to a single number? If you aren't putting the hot injector back in the same cylinder each time.......this could be why it moves to another cylinder each time it fails.
     
    MARK AT PIMCO TRANS Thanks this.
  7. MARK AT PIMCO TRANS

    MARK AT PIMCO TRANS Bobtail Member

    19
    8
    Dec 27, 2011
    SAN ANGELO,TX
    0
    Block was tanked upon crank replacement at machine shop. Pulled off pan. #5 piston scored. Pulled oil cooler jet looks good and clean. Fuel injectors were put back in same location since were replaced. Still checking on the other things. Anyone have a 3406 oil flow diagram for my education? Thanks for the help. -Mark
     
  8. windsmith

    windsmith Road Train Member

    7,296
    6,013
    Sep 2, 2011
    NEPA
    0
    Seems like all that is left to check is connecting rods. Are they bent or warped?
     
  9. MARK AT PIMCO TRANS

    MARK AT PIMCO TRANS Bobtail Member

    19
    8
    Dec 27, 2011
    SAN ANGELO,TX
    0
    1,3,4,5,6 con rods and bearings were replaced with cylinder packs and have 3,000 miles on them. #2 cylinder pack has 50,000 miles. I know "new/reman" replacement parts can be junk new, but this would be the third time on a different cylinder each time. Still checking into oiling and cooling systems. No performance/drivability concearns leads me away from fuel system, but open and appreciating to any help. -Mark
     
  10. ironeagle2006

    ironeagle2006 Road Train Member

    Sounds like there is a Chunk of metal in the oil passage feeding the cooling jets for the Pistons. Had a JD 4WD that did the same thing to my First boss in the fall of 1994 he bought it CHEAP with a busted crank in it from the dealer and fixed it. We started Scoring Pistons the next spring and it would be a differant one every time. We solved that one by plugging all the oil cooling jet outlets but one and putting full Pressure Oil thru the system and out she popped. See not even a Hot tank will get all the crap out of a motor it might have missed something you need to blast all the passages clean be amazed WTF can get caught.
     
    MARK AT PIMCO TRANS Thanks this.
  11. cowcatcher

    cowcatcher Light Load Member


    I agree with ironeagle2006 that you have debris stopping up the oil passage. Hot tanking want always get everything so you should go back afterwards and blow through with shop air. Best of luck finding the root cause.
     
    MARK AT PIMCO TRANS Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  • Draft saved Draft deleted