2001 Freightliner Classic XL/N14 Cummins

Discussion in 'Freightliner Forum' started by Cummins525, Jul 4, 2013.

  1. Cummins525

    Cummins525 Bobtail Member

    9
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    Jul 4, 2013
    Missouri
    0
    I have a 2001 Freightliner classic XL with a 525 N14 celect plus engine, I am having issues with oil pressure and water temp, oil pressure when cold at idle is about 32psi when fully warmed up at idle at 700rpms it's usually 10-12psi when running the oil runs 25-28psi, at 1500-1650 Rpms. If the oil temp gets over 200 degrees (which it usually does) pressure will drop to 21-24psi at 1500-1650 rpms. I use Lucas it helps a pound or two but not long, if I change oil filter pressure will stay good around 26-27 for maybe 2000 miles then drop again. I've put new oil pumps, not the prob, what all can I check before getting internal. It's got 1.6 mil miles with a complete out of frame over haul 6 years ago. And as far as water and oil temp, I've put in new radiator new water pump, new thermos, and ran overhead. Runs good just pulling little hills will get engine upwards of 205-210 and oil will get up around 215-230. Any help is very much appreciated. Thank you
     
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  3. bubbanbrenda

    bubbanbrenda Road Train Member

    1,388
    649
    Feb 27, 2011
    Middletown,Oh.
    0
    The oil pressure problem is probably the piston cooling nozzles,
    http://www.cumminspartsdirect.com/Category/1849-piston-cooling-nozzles.aspx
    $4.00 each.
    N-14's are famous for this. How much boost are you making? Did they replace the turbo when they over hauled it? How hot is the pyrometer getting in a pull? The nozzles will fix most of your oil pressure symptoms, and some of the water temp problems, but if not you will need to know how long ago did you replace the radiator? Where did you get it?
     
  4. Smellfunny

    Smellfunny Road Train Member

    1,376
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    Jan 28, 2012
    South Carolina
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    Replace all 6 piston coolers like b&b stated. At around 800k miles is a good time to roll in rod and mains on a N-14. Not sure how many miles is on your engine but if the piston coolers are good then this is another area that will effect oil pressure.
     
  5. Cummins525

    Cummins525 Bobtail Member

    9
    17
    Jul 4, 2013
    Missouri
    0
    Radiator is 1 year old, was bought brand new in Detroit Michigan. Boost psi is 25-30 during pulls, pyrometer usually stays around 700-800 unless pulling west coast mountains then it can creep up to 850-900 degrees. No, turbo was in good shape and was not replaced, it had all new rod and mains put in 3 years ago also,
     
    Last edited: Jul 4, 2013
  6. Cummins525

    Cummins525 Bobtail Member

    9
    17
    Jul 4, 2013
    Missouri
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    *Update* just pulled all coolers out, one was busted in half, one was cracked up by O-ring but in tack. I replaced both, but another one has tiny crack by where pin goes thru top where it bolts on to block. I have to wait till tomorrow when parts stores are open again to get more I will probably get 6 of them replace the other 4 and have 2 spares image.jpg that is a pic of my oil piston cooler tube, i've circled where 2 are/were cracked, and 1 separated there completely in half.
     
    Last edited: Jul 4, 2013
  7. Cummins525

    Cummins525 Bobtail Member

    9
    17
    Jul 4, 2013
    Missouri
    0
    I've replaced the coolers, and with oil and water temp at 180-190 and running 65 mph at 1450-1500 Rpms my oil psi is still at 20-25 psi max
     
    x#1 Thanks this.
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