V8-380 overheat - Sand

[greenhut]

Dropped anchor yesterday alone on the boat - relatively windy day for ATL. Had a snooze and woke unhooked with outdrive in a sand bar. Noooooooooo. Yes. Did my best to lift her out, started engine, and 3m later overheat warning. Noooooooo. Shut her down and ordered a tow.

Pulled water pump face and water streaming into boat tells me restriction between outdrive and pump unlikely. Impeller looked good. Restarted and overheat again. I must have pulled a bunch of sand into the system, obstructing flow. Heat exchanger? 2020 V8-380 the one with the square (not cylindrical) looking heat exchanger. How do you back flush the heat exchanger? Appreciate any tips. Knew the cooling system in my 8.1 inside and out, but this engine new to me.

 

[Horigan]

I would start by backflushing from the raw water pump inlet to the drive, then from the heat exchanger raw water outlet to the output of the raw water pump (let the water flow into bilge and out boat drain port). If you get good flow, then I would take off the end caps of the heat exchanger and fully flush all the passages. This would be a good time to run an appropriately sized metal rod down each passage to clean out any accumulation. You can get replacement end cap rubber gaskets from Fisheries Supply, or maybe iBoats.

if you don’t get good flow from the heat exchanger output, then move to the exchanger inlet backflushing to the raw water pump, and further upstream to the pump, until you get good flow. Where ever you find the restriction, be sure to fully flush that component, such as the oil or power steering coolers.

 

[greenhut]

Thanks Rich - I will be a flushing...