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FL70/CAT 3126 Injector Seal Problem

Discussion in 'Truck Talk' started by mikecop, Mar 18, 2001.

  1. mikecop

    mikecop New Recruit

    This week I had an unexpected, and expensive, experience will loss of oil. I have a 98 FL70 with the CAT 3126 engine, with 312,000 miles on the vehicle. I was driving at a fairly normal rate of 65 MPG at 1700 RPM and 35# oil pressure. Suddenly my oil warning light came on, and the oil pressure dropped to about 10#.
    I couldn't find any leaks, and the mechanic at the TA couldn't find anything, but I was down 6 gallons within a 10-gallon system!
    It turned out that my loss of oil was from the injector seals letting go, and the oil was sucked into my diesel fuel tanks. I had black diesel fuel. Six new injectors and other parts cost me $1405 in parts and $270 in labor. The mechanic at Great Lakes Freightliner stated that this is not an uncommon problem with the 3126 engine.
    If you have an oil loss and can't find any leaks, check your diesel tanks to make certain your injector seals haven't let go.
  2. WendyCal

    WendyCal New Recruit

    YIKES! Did you have to have your fuel tanks drained, too?

    Thanks for the heads-up on this, MikeCop!

    Godspeed to all of you out there on the highways and byways!
  3. Bearcat

    Bearcat New Recruit

    That sucks big time. I have a 3126B in my 2000 and hope this never happens. Is your engine the 3126B or is it just a 3126? Not sure if there is or not or what the difference might be.
  4. Weave

    Weave New Recruit

    The only difference between the 3126 and 3126B is the B is a later version with revised emissions. They both use the HEUI fuel injection system which uses the engine's lube oil to power the injectors. So if the injector oil seals fail, you lose your oil through them. These engines have about half a dozen other sucky features I won't mention because I'll scare people. Cat's big engines are good, but unfortunately their little diesels stink. BIG bucks to rebuild, too. The Cummins engines are a much better bet for medium sized trucks.
  5. simon says

    simon says New Recruit

    Cat vs. Cummins, or 10L?

    I have a Pete with the 3126B and Cat says this is why clean oil and an analysis program/ drain interval is so important. I have gone up to 12K on a small sump but may settle for 10K. I would love to go up to a 10-12L Cat and roll out of this unit after three years, but the uptick on a such a Class 8 truck is about $15,000. If I can get a lease next time, I may settle on the Cummins 8.2L and at least 275-300 another Pete/Kenworth. I have seen some complimentary remarks about the 8.2L C., but most dealers say they see this motor in for warranty repairs more often. It still has only a B-50 life of 500K miles as the 3126B, despite the wet sleeves. How is the new 24 valve electronic? Anyone have a lot of miles on this yet, and have some feedback?
  6. simon says

    simon says New Recruit

    If what you said about speed and rpm's is correct, you must have a very low R/A ratio. I don't think I would spec lower than 3.7 max and most Pete/Cat dealers think 3.9 is best for power/fuel balance with a top end of 73 mph. If you're stuck here, maybe you need to bump up your hsp. to 275 to compensate and/or downshift more to prevent lugging on grades. I would call Cat and ask for advice.
  7. louixo

    louixo Active Expediter

    i had a similar problem. the injector cups. same engine. just over 300,000 miles. cost me $2300 and the loss of 2 days. i had them all replaced, seeing as they were in there anyway. next time i go cummins.
  8. crazy larry

    crazy larry New Recruit

    The 3126 and the cummins 6-BT or 5.9L are what you call throw away motors...Usually around 300,000 to 400,000 the best thing to do is throw them away. This is when the problems start and continue....Trust me, I had a bunch of 6-BT's-it's the same motor they put in the Dodge pickup......Those motors will eventually put you in the poor house-they were not designed to run cross country, but they will never admit that......

    I would recommend the best motor for a expeditor is a Detroit 50 series...I now have 730,000 miles on it, and haven't touched it....It has not cost me one cent in repairs.....
  9. Weave

    Weave New Recruit

    Yes, they are both "throwaways"- the 3126 and the B5.9 But..
    B5.9 Cummins can be swapped with a factory rebuild for around $8K, reasonable in my book. A 3126 Cat costs 12-14k to replace, unreasonable. The Cummins is an affordable 3-400k throwaway. Both the Cat and Cummins junk engines will go past 500k miles with reasonable care though. I am glad to hear some good high mile feedback on the DDC series 50. It makes sense as it is essentially a series 60 minus 2 cylinders. Yours will probably be in for a rebuild (in frame, of course), soon- let us know what the rebuild costs.
  10. geo

    geo Active Expediter

    one way to cut down on problems with engines is not to idle and
    250 hours of idle equals 10,000 miles down the
    road, put on a genset to cut out the idle and save on engine
    i had a fl60 with cat engine on it , and a proheat ice
    kept 6500 hours of idling off of the engine, so at 312,000
    and 227 hours of idling, also saved $12,000 and 4,000 in maintance
    by having a genset on the truck also have one on my new western
  11. Bearcat

    Bearcat New Recruit

    What is the name brand of your genset? If you have the web site, let me know. Am currently looking for one for my fl70.
  12. Bearcat

    Bearcat New Recruit

    I found the proheat ice web site. Don't think this will work. Might have to look for a generator and run a plug into the cab and hook up a heater . If anyone knows of a generator, please list it so I can check it out.
  13. Bearcat

    Bearcat New Recruit

    I reposted this request in a seperate subject in the main conference. Please post there. thanks again
  14. simon says

    simon says New Recruit

    RE: FL70/CAT vs. Cummins 8.2L 24V Elect.

    I am still looking for some feedback on the new 8.2L C engine. I know the 5.9L is grossly inadequate. The 8.2 is still a 500K motor, but wet sleeve rebuildability over 3126B. I hear there is a new 3126 coming out, but probably same potential problem. As far as I know, the Det. 50 is only offered in the Freightliner (or Sterling line)- neither of which push my buttons. Cat C-10 or 12 is a possibility in a Class 8 truck, but at what cost to fuel efficiency even if geared for same? Thanx anyone.

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