Need help!! Cooling issues

[lgw1975]

4.3 Volvo Penta I/O - We have replaced the impeller recently. This seemed to fix out overheating concern. UNTIL, this Saturday at the lake. The boat was still running hot. After a few hours of work from patient friends, they removed some debris (seemingly from the bad impeller) from the themostat & housing. We are still not getting adequate water to the engine.
There seems to be something blocking the water flow from the foot? Has anyone had these issues and if so, how do I go about clearing out the debris?
(Also, I am very sorry for my ignorance...)

 

[Robert D]

Re: Need help!! Cooling issues

This is why you want to replace the impeller every year, regardless. Once you've ruled out everything up to the pump, then you are left with fragments of the old impeller floating around your engine, the exhaust manifolds, etc, etc. Picture tearing everything with a water jacket apart and cleaning any debris out.....see the point? The block, heads, manifolds, hoses.....you already found some in the thermostat housing, so you know there is probably more to be found. Suddenly that impeller doesn't seem so expensive????