PCM 6.0 model409 losing coolant

CentCent Posts: 264 Baller
I have a PCM 6.0 model 409 that is losing coolant from the closed part of the cooling system. Will go from Max fill line to minimum fill line in less than hour I believe.

I cannot find a leak in any line after looking. Do not find coolant in the bottom.

Anyone with a similar experience? Any ideas? Solutions?

The boat has a heater and the connections are not visible. I may take out front panel and try to access it. Not easy. Tight area.

Thanks for any help.


  • unksskisunksskis Posts: 662 Crazy Baller
    Mine is a full closed (2011), and leaks out at the seams/gaskets on the manifolds.
  • skihartskihart Posts: 545 Solid Baller
    Any issues with the heat exchanger? Did a good job draining it in the fall?
  • CentCent Posts: 264 Baller
    Coolant part is not drained in fall. Other part of system was drained.

    Put on about 16 hours since back in water. Coolant was low when went back in. Topped off. After 16 hours lie again and seems to be losing coolant.

    Just checked up by heater hoses. There on back of heater so could nit reach to tighten but carpet is dry under them.
  • GloersenGloersen Posts: 1,254 Mega Baller
    Assuming no engine issues, oil is good (no signs of head gasket leak), etc. Might consider pressure checking the heat exchanger to rule out coolant to raw water leak/loss within the exchanger.
  • DanEDanE Posts: 935 Crazy Baller
    Does it continue to leak below the minimum or does it stay that way?
    It's pretty normal with a low level when you got a heater, don't think you can expect the level to stay at the top mark as the expansion volume becomes insufficient when a heater is installed.
    @Jody_Seal ?
  • CentCent Posts: 264 Baller
    Thanks. Pulled dipstick and oil looked fine to me.
  • DWDW Posts: 2,516 Mega Baller
    You should be able to “borrow” a radiator pressure tester from an auto parts store if the tank uses a typical radiator cap. If a head gasket is suspect a leak down test would blow bubbles in the tank.
  • KelvinKelvin Posts: 1,337 Mega Baller
    My 2011 was leaking from a joint between 2 of the full metal exhaust pieces. Don't have that boat anymore to take pictures to show you.
    Kelvin Kelm, Lakes of Katy, Katy Texas
  • RichardDoaneRichardDoane Posts: 4,834 Mega Baller
    edited June 14
    you should be able to get a pressure cap adapter for the reservoir and put pressure on the system when cold. be patient and keep checking for seepage. coolant doesn't just magically disappear.
    BallOfSpray Pacific Northwest Vice President of Event Management, aka "Zappy"
  • CentCent Posts: 264 Baller
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