Results 1 to 7 of 7
  1. 06-29-2020, 11:01 AM #1
    johnmr12
    johnmr12 is offline
    Member
    Join Date
    Aug 2007
    Location
    Idaho
    Posts
    188

    Optimax running cold

    I have a 2001 Optimax 225 3L DFI engine. I noticed it was running cold this past winter. Sometimes it would stay under 100 degrees. So I replaced both thermostats with the 130 ones, and I replaced the poppet valve. One of the thermostats was actually broken. It made a slight difference but now it never gets over 113. I can live with 113, but I'm wondering why it isn't running closer to 130. We have had some 90 degree days here and it still never gets above 113. I have the smart craft gauge on here so that is what is giving me the reading. Is it possible the gauge is malfunctioning? It does show higher readings when I first start up to run to a different spot, but then it quickly drops to 113 and stays there. When I first start it up in the morning its well below 100 and then it rises to 113. But it is always at 113 when I am running no matter how long the run is.
    Reply With Quote Reply With Quote
  2. Jtreed99
    Jtreed99 is offline
    Member
    Join Date
    Mar 2017
    Location
    Tuscumbia, AL
    Posts
    1,069
    #2 06-29-2020, 11:05 AM
    On plane temperatures do not matter unless you are overheating. Within 5 minutes of starting your motor, at idle, do you reach 120? That is the only important question as far as the stats are concerned.
    Reply With Quote Reply With Quote
  3. SilverFox579
    SilverFox579 is offline
    Member
    Join Date
    May 2011
    Location
    Spangle, WA
    Posts
    6,211
    #3 06-30-2020, 09:24 AM
    ^^^^+1^^^^
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax

    Reply With Quote Reply With Quote
  4. EuropeanAM
    EuropeanAM is offline
    Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    95,166
    #4 07-02-2020, 02:04 PM
    Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the REQUIRED Info (serial number) when posting. Thanks!

    Please respond to Post# 2 for further assistance.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
    Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
    Reply With Quote Reply With Quote
  5. johnmr12
    johnmr12 is offline
    Member
    Join Date
    Aug 2007
    Location
    Idaho
    Posts
    188
    #5 07-09-2020, 03:47 PM
    It warms up to 113 and stays there. When I run it varies between 111 and 114.
    Reply With Quote Reply With Quote
  6. apenland01
    apenland01 is offline
    Member
    Join Date
    Jun 2018
    Location
    Tucson, AZ
    Posts
    2,159
    #6 07-09-2020, 04:30 PM
    Where are you getting your readings from? You should see well below 100 degrees when running.

    I had this problem and replaced my thermostats and it's been working great since. I always let my engine cycle to 135 and back down to 120 before going wot.
    1994 Ranger 492VS
    2004 Optimax 225 - 0T920364
    6" Hydro Dynamics Manual Jack Plate
    24p Fury 4
    24v 47" Lowrance Ghost / Lowrance HDS

    Reply With Quote Reply With Quote
  7. Savage
    Savage is offline
    Member
    Join Date
    Jul 2004
    Location
    Penn PA
    Posts
    15,189
    #7 07-09-2020, 08:24 PM
    Click on this thread >>>>>Temperature of engine still not right


    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »