Join Date: Sep 2007
Location: Pasadena Md - Magothy side
Thanked 31 Times in 31 Posts
Rep Power: 10
Re: Yanmar 4JH-2E using coolant
Simple, cheap and effective way to check - put dishwashing soap in the coolant tank.
If you blow bubbles you have a leak in the exhanger.
Same thing works to make sure your impeller is working (if you have an under water exhaust) - soap the impeller - crank the engine and look for bubbles.
Lessons learned are opportunities earned.