Boat threw a code

[HoytS]

Does anyone know what this code means??

[pauldixon]

Yup - just wrote a DIY here - https://www.planetnautique.com/vb5/f...overheat-zr409

[HoytS]

Thanks I will give it a try and see what happens

[Scooter G]

You can also refer to pages 244-245 of the diagnostic manual, there a few plausible conditions that will throw that code. Guessing your G is pre 2016?

PCM Diagnostic Service Manual.pdf

[HoytS]

It’s a 2015. It threw the code when I was winterizing it. Quite odd I thought

[jpwhit]

How were you winterizing it? The exhaust manifolds are cooled by the excess raw water pulled into the system. If you're not providing an adequate quantity of raw water the engine will have enough water to cool, but the exhaust manifolds will overheat and result in that code. Another way of saying it, it takes a lot more raw water to keep the manifold cool than it does to keep the engine cool.

An example that'll cause this to happen, if you're sucking antifreeze out of bucket to feed in as the raw water supply, you'll cause this problem if the hose is too small, or you're making the raw water pump suck the antifreeze up too far. When winterizing this way, it's best if the container that's the source of the antifreeze, to be above the raw water pump. And the container should never run dry while the engine is still running.

This is one of the reasons I'm not a fan of using the sucking antifreeze into an engine as a method of winterizing, and also why it's not the recommended method recommended by PCM and Ilmor. The other reason is the outcome of the sucking antifreeze into the engine is not 100% deterministic. Meaning there isn't a way to be 100% sure the boat is properly winterized. Most people just run it long enough to be pretty sure the engine loop has enough antifreeze in it.

[HoytS]

I had a garden hose plumbed into the raw water intake hose. The engine hadn’t even got up to full temp when the code was thrown. And yes I use the antifreeze and bucket method. It’s not perfect but the boat is inside and insulated shop during the winter with a minimal heat source. Mainly winterizing incase the building loses power and have no heat.

[pauldixon]

Good call jpwhit - if the boat is not running in a lake the code may have been caused by a lack of water flow. That would take a while I would think though - more time than just the time it takes to suck 5 gallons of antifreeze though?

[Scooter G]

Not necessarily, at 800 rpm's +/-, that is 8 blow torches hitting raw metal 800 times in a minute. Exhaust manifolds heat up to cook a burrito fast.

[jpwhit]

I had a garden hose plumbed into the raw water intake hose. The engine hadn’t even got up to full temp when the code was thrown. And yes I use the antifreeze and bucket method. It’s not perfect but the boat is inside and insulated shop during the winter with a minimal heat source. Mainly winterizing incase the building loses power and have no heat.

Exhaust manifolds can easily overheat before the engine is up to temp if the quality of raw water is insufficient.