Brought to you by:

Twenty Years!
.
The best source of parts, bar none!

Click here to see a list of our Supporters.
  • If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Announcement

Collapse
No announcement yet.

Engine work on my L-9000

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Engine work on my L-9000

    My 88 L-9000 tri-axle dump has been humming along for a few years now. (Cummins 350 big cam) I decided to take a couple weeks off about a month ago and do 2 things to it, replace the bed floor, and "run the overhead", that is, pull the rocker covers and jakes and adjust the valves and injectors. It has less than 100,000 miles on an in-frame overhaul, and I replaced the injection pump less than 50,000 miles ago, but still had a little too much smoke, both black and blue. I don't mind the black too much, it wasn't too bad anyway, but I hated the blue smoke, it really makes a vehicle look bad. It didn't smoke all the time, just some on the cold start, and then pretty much for a little while after a short idle period. Shortly after I bought the truck almost 20 years ago, I had a mechanic run the overhead for me, and that cleared up most of a smoking issue it had then. That was a different engine than what it has now.

    It all went well, the intake and exhaust valves weren't too far off, and this time, I did the injectors 0 lash, plus one quarter turn. Unlike last time, when I just put them at zero. No more smoke!! Either black or blue, Not sure why those adjustments affect that, but I'll take it!

    Back to work for 4 days, seemed to have slightly less power, but was running good. Then last Thursday, going down an interstate hill with the jake on, BANG, clatter clatter, puff of smoke. Headed for the emergency lane, still running, but a dead miss. Oil pressure and temp were normal. Left it idle and opened the hood, nothing obvious to see. I immediately thought maybe a broken valve spring or rocker, but I had to get out of there, a busy interstate, cars whizzing by a few feet away. An exit only a few hundred feet ahead, and I knew there was a big parking lot just at the end of that ramp. Gently limped it up there (about 18 tons of dirt on) called the dispatcher, called my friend Don, we quickly agreed to just call the hook, can't take a chance on something loose in there tearing up the whole engine. About a 12 mile trip home, I asked the wrecker guy as he was hooking up "we don't have to take out the driveshaft, do we?" He said "uh, yes. I've seen these transmissions blow after only 6 miles, there's an oil pump on the input shaft. Unless you want to hold that clutch pedal down all the way the whole time. It's tough, but I've done it." I just moaned and groaned about what a job it is taking that drive shaft out, and he said "oh I'll do it". But "you don't come cheap" I told him, "I'll just hold the clutch down, I'll take rests and change legs at traffic lights." So that's what I did, it worked well. Put it in high gear so everything in the trans turns, then no chance of a lube problem. Never thought of that before, though it's probably not considered very safe to ride in a vehicle hanging on a wrecker, especially when it grosses about 68,000 pounds. That tandem KW wrecker knew it had a load! An 88 model, same year as mine.

    But now it's home, pulled the covers, can't see anything wrong, pulled the jakes, still can't see anything. Idling, all the movement seemed normal. Shot the exhaust manifold with a temp gun to try to find a cold cylinder, but the temps were even throughout. Went to bed Friday evening not knowing what was wrong, not fun. Don was calling around trying to find out what needed to be done for a compression test, but wasn't having much luck. Next day, started checking the valve clearances, wondering what I could have done wrong. Paying special attention to the exhaust valves, because the jake was on when it popped. Got to the last one, the exhaust valve on #6, and it was tight, was supposed to be .023. I was by myself, (Saturday morning) but Don told me on the phone to start pulling the rocker boxes, and start with the rear one, since that's where the tight valve was. (this is a 3 head engine) Got the rear one off, pulled out that exhaust push rod, and gave it a look. Wait, is it bent? YES! I was never so happy to find something bent in my life! It wasn't obvious without a close look, but it was there, and I knew I was in the right place! Hopefully just a screwed up head, get a replacement, and back on the road in a few days. Not so lucky though, as soon as I moved the head off I saw the cooked piston, and a scored up liner. Laid the head over and see that it has one valve seat missing. So it dropped a valve seat, mystery solved. Glad I didn't try to drive it home, probably would have locked it up.

    It's all apart now, waiting on parts from Michigan. (piston, liner, push rod, rebuilt head, 2 new injectors)

    23 Alt / Rick, are you here? I have a couple of questions! 1) I got the rear head off without removing the intake, am I gonna be able to get the new one on without removing it? And 2) Does zero lash plus 1/4 turn sound right to you on the injector adjustments?

    Marc

    88 L-9000 tri-axle dump
    71 F-250 4x2
    88 F-150 4X2

  • #2
    20190406_115053.jpg Lower right valve
    Marc

    88 L-9000 tri-axle dump
    71 F-250 4x2
    88 F-150 4X2

    Comment


    • #3
      20190408_095752.jpg
      Marc

      88 L-9000 tri-axle dump
      71 F-250 4x2
      88 F-150 4X2

      Comment


      • #4
        If you get by just building one hole you got lucky! That could have been nasty. Did you find the remains of the valve seat? I’d be checking the exhaust side, wouldn’t want it to get to the turbo.....
        ----1999 F150 XLT Lariat Super Cab 4X4 5.4----
        -----1947 Lincoln Zephyr Coupe 5.0-----
        -----2005 Expedition Eddie Bauer 5.4----
        " Sometimes you fix the car, sometimes the car fixes you" Steve L.

        "Do not let anyone tell you it cannot be done. No challenge can match the heart and fight and spirit of America". President Donald J. Trump

        Comment


        • #5
          No I didn't, I suspect it mostly melted and/or is embedded in the piston. The clattering stopped after only a few seconds, I don't think the seat lasted long at all. There is some metal pieces in the pan, not sure if that's it or how it got there. We'll look things over carefully during assembly. Piston 5 is a little bruised up too, we'll be replacing it as well. I remember 4 years ago when we put these (rebuilt) heads on, and one of them, this one, really looked questionable to Don. He said back then that if we weren't pressed for time,, he'd send that one back, it was just old and beat-up looking. Well, this is how long it lasted. a little less than 100,000 miles. New stuff, and one rebuilt head, is coming from a different place this time, on the way now from Michigan, should be here tomorrow or Thursday. I hope it looks good, because I'm pressed for time this time as well. I need to get back to work! I've been using these couple of days, today and tomorrow, to clean up and repaint the tailgate. This place wants the old head for a core, Don told him it's a POS, and he asked "is it broke in half?" Don told him it wasn't, and he said he'd take it! I'm glad to get the core price for it.

          I was thinking today, it must have looked strange to the car guys here, reading how I took off a head without taking off the intake! I might be calling it by the wrong name, but it does the job of an intake to me. It's on the side of the motor as you know, a quick look at one of these engines would make it clear how it was possible for me to do that. I'll get some more pics in the coming days.
          Marc

          88 L-9000 tri-axle dump
          71 F-250 4x2
          88 F-150 4X2

          Comment

          Working...
          X