Click for Chrysler parts and manuals!
Results 1 to 3 of 3
  1. #1

    Default LM 318 High Oil Pressure

    Hi Guys,

    I recently changed the oil and oil filter in my Chrysler LM 318. I now have a higher oil pressure, its moved from the Operating Manual specified pressure of 65 psi to around 85 psi. I'm not sure if I should be worried by this and don't know why it would have changed.

    The new filter is the same brand and type as the one I replaced and while the oil is not the same brand used before the oil is the correct specification SAE 30, 20W-50.

    Any advice you can give would be appreciated.


  2. #2
    Join Date
    Mar 2009
    Portland, Oregon,

    Default Re: LM 318 High Oil Pressure

    Most engine oil pumps control pressure via a bi-pass or relief valve. These are pre-set.
    The pumps themselves are capable of producing much more pressure.
    It would be uncommon for the bi-pass or relief valve to change value.

    Engine oil may begin to cavitate when pressure exceeds 45/60 psi.

    I would temporarily install a known-to-be-good mechanical gauge and verify the actual pressure that you are seeing on the OEM gauge.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP drives

    "Intellectual growth should commence at birth and cease only at death." Albert Einstein

    Please... no PMs! Post your questions on the forum.

  3. #3
    Join Date
    Dec 2014
    Ontario Canada

    Default Re: LM 318 High Oil Pressure

    My manual indicates SAE 30 weight oil or an alternative 20W-40 for my 318.
    20W-50 might produce a slightly higher oil pressure, but I wouldn't think as much as 20 psi higher.
    It could be that you have a bad oil filter right out of the box, all else being unchanged.
    Click image for larger version. 

Name:	Engine oil viscocity.jpg 
Views:	18 
Size:	25.9 KB 
ID:	20763

Similar Threads

  1. 50FBYPBC what pressure on high pressure line?
    By Cannageneticsbank in forum Volvo Penta Gas Engine Forum
    Replies: 5
    Last Post: 05-06-2018, 03:04 PM
  2. Replies: 2
    Last Post: 07-11-2017, 06:16 PM
  3. Bf130 oil pressure too high pressure relief valve question
    By Backchannelmako in forum Honda Outboard Forum
    Replies: 11
    Last Post: 05-07-2014, 09:46 PM
  4. 97 175 HP Ocean Pro high water pressure and high temp
    By phillipsfixit in forum Johnson Evinrude Outboard Forum
    Replies: 2
    Last Post: 09-19-2013, 11:01 PM
  5. High pressure fuel pump putting out to much pressure
    By Bluecollerboater in forum Volvo Penta Gas Engine Forum
    Replies: 1
    Last Post: 06-25-2013, 12:45 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts