Moomba MAX raptor 400, coolant issue

It's the end of the season, sadly. I bought my Max like 6 week ago and i had a strange issue with my coolant system. When i first did my 25hr i dropped the oil and changed the gas filtrer as needed and i've checked the prestone level to see where is it and surprise, no prestone in the bowl. there is no leak, the motor is shiny.

I called Sport Marine and they told me that maybe there were air bubble in the system, so full it back up and now after another 30hr, there is still no prestone in the tank..

Any idea ? thanx

If you are sure it’s not an external leak, it can only be an internal leak.

Has it ever overheated?

Possibly a warped or cracked head, head gasket or cracked intake manifold.

Being under warranty, I imagine the dealer will do a pressure test on the cooling system to try and identify the source of the leak.

I would bet it’s a slow external leak that simply gets purged with your bilge water.


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Quote:

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Originally Posted by larry_arizona

If you are sure it’s not an external leak, it can only be an internal leak.

Has it ever overheated?

Possibly a warped or cracked head, head gasket or cracked intake manifold.

Being under warranty, I imagine the dealer will do a pressure test on the cooling system to try and identify the source of the leak.

I would bet it’s a slow external leak that simply gets purged with your bilge water.


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Thanx for the answer, internal leak would be surprising,the boat is brand new with 30h on it. I'll take a closer look next year while the engine is running and try to see for the external leak first... At first view the motor is top clean.

At the next oil change, take a sample and set it off for a test.

Never looked into a lab for testing. I assume that is where you send it.

Blackstone Labs - $28 from Google.


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Used black stone a lot. Great lab, however coolant internal leak is very easy to see in oil, it turns to chocolate milk pretty quick (no pun intended).

You can have an internal coolant leak that will not mix with oil directly into the combustion chamber and that will cause white smoke and a sweet exhaust scent. Could be difficult to detect on a boat......

I would agree with the op that it’s not likely a internal issue, but a slow external leak at a hose connection.

On an all black engine, a slow external leak would be tough to see as the heat of the engine would dry a slow leak quickly.

Might need to add a UV dye and use a black light while pressure testing the system.

I am sure your dealer will happily handle this for you under warranty free of charge.


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I was thinking the same thing when I first read this. Time for someone to get the UV light out.


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Yes, an oil analysis would show coolant, if its an internal leak. A large leak will certainly turn the oil into a milkshake, but a small leak will not, but higher levels of coolant could show on a test.

Just noticed my coolant reservoir is low on my 400, it was topped off at 20 hours and is low again at 39 hours.

Oil is clean and hull dry, obviously a slow leak.

Curious if OP found source of leak on his raptor 400.


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Quote:

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Originally Posted by larry_arizona

Just noticed my coolant reservoir is low on my 400, it was topped off at 20 hours and is low again at 39 hours.

Oil is clean and hull dry, obviously a slow leak.

Curious if OP found source of leak on his raptor 400.


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Check the hoses for leaks, I found mine near the heater pump.

Cool thanks, I will check all hose clamps first.


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any updates on what OP and Larry_arizona found? Im having the same issue on my '17 Mondo. Oil is clean and hull is dry as well.

Thanks

Quote:

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Originally Posted by FFJesse

any updates on what OP and Larry_arizona found? Im having the same issue on my '17 Mondo. Oil is clean and hull is dry as well.

Thanks

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Start the boat, let it reach 155+ then check all the hoses. If you have a heater, check the pump near the rear port side engine compartment.

Had the same issue when we winterized last year, no coolant in the tank at all. Dealer wasn't concerned. We topped it off at the beginning of the season. I will double check tonight.

Not thrilled with Indmar hose clamps.

Otiker clamps really are not adjustable and certainly not reusable.


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There is another thread on this issue. My 2016 CRAZ was also low on coolant. I got an overheat warning and took her to the dealer and all it was that the coolant was low. They checked for leaks and there were none. I think these engines consume coolant, which can’t be good. I haven’t added coolant to my cars in many years, why should a marine engine be any different?