Fitting After Market Gauges to Yanmar 3 YM30

[FullCircle]

I think I have the same engine as you and have had alarm many many times. Slowing to 1500 rpm or so for 30 seconds shuts it off. And the engine IS overheating, have had engineer with laser temp gauge on board when it happens. On the original undersized heat exchanger I could guarantee overheating within 10 mins above 3200 rpm, on the new one it can still happen, but only very occasionally. Engine still runs very well, starts almost instantly, smooth, no smoke.

I have run mine a couple of years agoat 3400-3500rpm for over 2 hours bashing into a headwind against tide. No more overheating for at least the last 6 years now.

I use undiluted coolant and change it every 3 years. I would not concern yourself about getting every last drop out, after all, you probably don't apply the same rigidity to your oil changes ? So a % of the coolant gets mixed with lots of the new good stuff, won't come to much harm.

The coolant doesn't attack the metal, but does inhibit water flow if it gels in the heat exchanger.

 

[RichardS]

I use undiluted coolant and change it every 3 years.

I've never tried that although the heat conductivity of antifreeze is actually worse than a 50:50 mixture as well as the freezing point of pure antifreeze being higher. I would guess that the anticorrosion properties are better than the diluted version but as you are changing it every 3 years even that is not really giving you any payback.

Richard

 

[FullCircle]

I've never tried that although the heat conductivity of antifreeze is actually worse than a 50:50 mixture as well as the freezing point of pure antifreeze being higher. I would guess that the anticorrosion properties are better than the diluted version but as you are changing it every 3 years even that is not really giving you any payback.

Richard

£1 A YEAR.....

 

[RichardS]

£1 A YEAR.....

£1 a year to get reduced engine cooling and poorer antifreeze protection? Sounds like a GREAT DEAL .......

Richard

 

[tgpt21]

Just a thought but did you drain coolant out of both the drain tap near the oil filter and the allen key headed drain bolt in the lower large hose on the other side of the engine?

It took me a while to find the hose drain and to realise that it needs an allen key (3mm or 4mm, I can't remember). Even so, I reckon I have another 2 litres of coolant in the calorifier coil and its hoses which probably stays in unless you disconnect the hoses and I couldn't be bothered. However, I did flush through with plain water by getting the engine up to temperature a few times and then draining again before adding 4 litres of concentrated OAT coolant (including some in the expansion tank) and then topping up to full with softened water.

Richard

I used the tap near the oil filter and I removed the bottom hose AND I had the thermostat housing off to check it. Does any one have a source for a non Yanmar thermostat? I have tried Googling the trade mark markings on the ring of the thermo but cannot get a result. It opens at &" degrees according to the stamp.