Forum Discussion

mrwrenchman's avatar
mrwrenchman
Explorer
Jan 04, 2015

Engine fan

I have a 2006 Monaco with a 8.8L 400HP Cummins side radiator . Recently I noticed the engine fan is running full speed all the time . I know the fan is driven hydraulically and I think it thermostatically controlled . Is there a thermo. control valve somewhere that is possibly stuck in the wide open position , or some other condition .Any Ideas ? Thanks Don
Class A
  • Golden_HVAC's avatar
    Golden_HVAC
    Explorer
    Jan 04, 2015
    It is probably dirty. Try using a garden hose to rinse the radiator, then spray with something like simple green. Let it soak for 1/2 hour, and then rinse with more water. ..

    If you get off lots of dirt, that is your solution.

    Some municipal bus lines have a full time mechanic to just wash radiators every day. One even went to the expense to make the fans reversible, and blow air the other direction for a few minutes each hour. This dislodges some of the dirt every hour.

    Good luck!

    Fred.

About Motorhome Group

38,708 PostsLatest Activity: Mar 05, 2025