Results 1 to 2 of 2
  1. #1
    Join Date
    Jun 2014

    Default Mercury Mercruiser 5.0 MPI Overheat problem

    Hello everyone,

    I have a 2006 SeaRay Sundeck with a Mercruiser MPI 5.0 and a Bravo 3 outdrive. A couple of days ago it started overheating in idle and during speeds of less than 7 mph above 7mph the temperature drops back to it 147 degrees. So I changed my raw water pump impeller first that didn't fixed it, then I changed the thermostat(160 degrees) and that didn't fix it either. My next step is the engine mounted water circulating pump tomorrow. If that doesn't do the trick, what else should I look at next? Any help with this would be greatly appreciated!! Thank you in advance for your help..

  2. #2
    Join Date
    Feb 2008
    Valencia, PA


    Get all the pieces from the impeller if they were broke off?
    Try taking off the water hoses from the thermostat and make sure they are clear?
    Our Alpha drive had a power steering cooler inline that has a "strainer" on the intake side that you have have some debris in.
    Does it overheat running on the garden hose on idle?
    2004 Supra Launch 22 SSV
    Indmar Assault 5.7L 325 HP
    "One More Hour"

Posting Permissions

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