Originally Posted by DeborahLee
A good auto coolant flush should take care of problem and clean the cooling passages in the engine also.
This, as he asked for coolant side cleaning, and said one yr old engine.
I took my Yanmar
Heat Ex out to clean it, filled a 5 gl bucket with about a 50% mix of Muratic acid, when I put the tubes in to clean them, it boiled like crazy.
I thought Wow, I didn't know I had much growth in there, it looked pretty clean, then the mix began to heat and the boiling got real vigorous. Then I thought, I know there couldn't have been that much growth, what is going on and removed it.
When I got a hard look at the tubes, it became apparent that the outside covering of the tubes was zinc, and I thought OK, that's why there are no zincs in my raw water
Mine is a 30 yr old 4-JHE, your results may vary of course, but overly aggressive cleaning may not be a good thing, especially on a one yr old engine.
I installed one of these in my hose that goes to the water heater, it is essentially the same as the heater hose on an automobile.
then connect a water hose and let it run with the engine drains and radiator cap off, water will flow through the engine and out all the drains, let the water run until clear, close drains and run engine until hot, then drain, if water drains out clear, your done. Fill with antifreeze
and go, if it is not clear, repeat until it is, if there is a lot of rust etc., remove the thermostat and replace the cooling neck and hose and that will allow water to flow through the engine un-impeded, do not operate the engine with thermostat removed for long.