Click for YF Listing Service Click for JetForums Click for Burger Click for Nordhavn Click for Westport

DDEC 16V2000 1800HP M90 - Low Oil Pressure

Discussion in 'Technical Discussion' started by GAGMC, Jul 25, 2024.

  1. GAGMC, Jul 25, 2024
    #1
    GAGMC

    GAGMC New Member

    Joined:
    Aug 21, 2023
    Messages:
    5
    Location:
    Texas
    We purchased a used yacht with rebuild DDEC 16V2000 M90 engines, 1800 HP.
    At Full Throttle, 2350 RPM, we are getting oil pressure 99 to 101 PSI.
    We've had different mechanics tell us that it is either great pressure or that ideally it should be above 100.
    We are curious to know what kind of oil pressure readings anyone else is getting on same engines at 1850RPM and above.
    They were built in 2001
    Last edited: Jul 25, 2024
  2. Capt Ralph, Jul 25, 2024
    #2
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,602
    Location:
    Satsuma, FL
    Rebuilt 23 years ago?
    Any oil lab records?
  3. GAGMC, Jul 25, 2024
    #3
    GAGMC

    GAGMC New Member

    Joined:
    Aug 21, 2023
    Messages:
    5
    Location:
    Texas
    The engines were built in 2001, rebuilt in 2022, maybe 300 hours since W6.
    We've put 200 hours since purchase, have had two oil samples and nothing out of the ordinary.

    We feel they are working properly and it seems as if the work was done well, just wondering who is correct, are sub 100 PSI oil pressure readings low for RPM above 1850 or normal.

    Our understanding is that below 90 would be obviously critical and low 90's OK but indicating potential issues.
  4. Capt Ralph, Jul 25, 2024
    #4
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,602
    Location:
    Satsuma, FL
    DDEC or MTU???

    What were the oil pressures after rebuild?
    What pressure history since?
    What does the other engine report for pressure?
    What is the factory recommendations for oil pressure?

    On our engines, I'm happy with 50PSI.

    It's not a PSI thing, it is oil flowing that is important.
    Oil pressure regulators and shunts are involved here also.
    Keep up with oil labs. IMO don't think you have a problem.

    One of our YF brothers here has like engines (MTU), just rebuilt. Maybe he can chime in here soon and tell us more of his operation specs.
    Last edited: Jul 25, 2024
  5. GAGMC, Jul 25, 2024
    #5
    GAGMC

    GAGMC New Member

    Joined:
    Aug 21, 2023
    Messages:
    5
    Location:
    Texas
    Good question. We purchased the yacht 175 hours after rebuild, we don't have the before, the data I am giving you is from our experience since purchase.
  6. GAGMC, Jul 25, 2024
    #6
    GAGMC

    GAGMC New Member

    Joined:
    Aug 21, 2023
    Messages:
    5
    Location:
    Texas
    Sorry, I did not see the rest of your questions, here are the anwers:

    I believe MTU purchased Detroit Diesel and these where during this period so they are MTU DDEC 16V2000 M90 1,800HP engines

    Oil pressure has been steady since we've owned the yacht, port engine usually reads 2 or 3 PSI higher.

    We are looking for others with similar engines to share their oil pressure readings at RPM higher than 1850

    If they are also getting high 90's we are going to call this issue good, if in fact they are having 105 to 110 (we've been told this should be the range) then we will look more into this.
  7. Capt Ralph, Jul 25, 2024
    #7
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,602
    Location:
    Satsuma, FL
    Last questions; Your measuring pressure from where?
    A real mechanical pressure gauge or the DDEC display?
    Your using what oil?

    I still don't think there is an issue but I don't push M90s.
  8. Capt J, Jul 25, 2024
    #8
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,593
    Location:
    Fort Lauderdale
    You have 99-101 PSI and you're worried about oil pressure? That is a ton of oil pressure and those motors would get properly lubricated at 1850 rpms with 40 PSI of oil pressure. Perhaps it's the brand of oil you're using or the brand of filters.
  9. Pascal, Jul 25, 2024
    #9
    Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,610
    Location:
    Miami, FL
    We have 2000hp 2004 vintage M91s on the 116 I run. Oil pressure is about 110 at 1800 rpm fast cruise and about 80 psi under 1000 rpm
  10. GAGMC, Jul 26, 2024
    #10
    GAGMC

    GAGMC New Member

    Joined:
    Aug 21, 2023
    Messages:
    5
    Location:
    Texas
    Both digital engine display and the gage in the engine room read the same.

    Because we are getting two different numbers from MTU mechanics, I thought to check to see what others are seeing.

    I do believe that somewhere around 85 or 88 PSI the engine will give an alarm, this is at higher RPM's, at lower RPM's the pressure is lower and that is OK.

    I don't want to bother everyone, was hoping to find others with similar engines and comparing notes.