M6di coolent leak

[gregtay]

We managed to get the hour meter up to 5 hours over the weekend and it looks like I do have some sort of small coolent leak on the M6.  When the boat showed up from the factory we noticed a little coolent on top of the motor (under the cover) but couldn't tell if that was a spill or an issue.  We smelt (very faint) coolent each time the motor has run but again, weren't sure what was the cause so I have kept a close eye on things.  Temp was fine, stayed around 166 but yesterday wanted to take a look again to see if there was any fresh coolent and sure enough there was a small pool of green coolent down in the bilge an a few hoses seemed wet (almost like it sprays a little when it does leak.) Couldn't find any active leak while at idle, so either it is a small trickle down a hose (and I can't see it dripping) or it only happens at higher RPM.  Anyway, I know a few others have had coolent/overheating issues withh the new motor... anyone else have an actual coolent leak yet?.. if so, what was the cause? 

I will get the boat back in the shop to have them take a look.  Other than that the new motor is running like a champ! 

[Sparky450]

Pm sent 

[gregtay]

Updating the thread:  My dealer (Seattle Boat) had the boat for a few day sand reached to Malibu on the issue.  The theory is that my engine cover on the M6di was not cut correctly (the hole int he cover where the coolant cap fits through.. it was was too small. This caused the cover to rub against the bottom of the cap and also caused interference so that the cap couldn't be correctly tightened which lead to coolant leaking out the top while underway.  So.. the fix is to cut the cover and make the hole bigger and Malibu is also sending a new coolant cap just in case.  I am going to watch things closely for the next few hours so make sure all the coolant stays in the motor this time:)

[Lindt]

Interesting. On my M5di the oil stick and coolant cap need to be removed before the cover comes off. Unnecessary “feature”, particularly the oil. Wouldn’t  appear to make any difference if the holes were bigger. The cover’s held in place by rubber grommets on posts. If more securing is required then a separate bolt would have been a better design rather than relying on the oil and coolant caps. 

[gregtay]

16 minutes ago, Lindt said:

Interesting. On my M5di the oil stick and coolant cap need to be removed before the cover comes off. Unnecessary “feature”, particularly the oil. Wouldn’t  appear to make any difference if the holes were bigger. The cover’s held in place by rubber grommets on posts. If more securing is required then a separate bolt would have been a better design rather than relying on the oil and coolant caps. 

Exactly... that is how mine was from the factory but that is no longer the case, they cut the hole bigger per Malibu's guidance.   (I can squeeze my dipstick through the hole when the cover comes off.. but I will go out and make that hole larger as well.)

[rsutton1223]

Pulling up an old thread. Did this end up fixing the issue? I had the same with mine and went ahead and cut the cover because it is a cheap fix if it did work.