Re: volvo penta 5.0 gl overheating
Sounds like it is probably the same pump. When you pull the hoses off the pump, the inlets may be plastic. The plastic inlet is press fit into the metal pump housing and (I think) has an internal, non-maintainable o-ring. If this is where you are sucking air, it's time for a new pump. You can try a quick fix to see if this is in fact the issue. Take some "emergency" silicone tape (got mine at the boat show a few years ago but now it is available at most boat stores) and wrap it around the plastic to metal joint on both the inlet and outlet sides of the pump. If you now have pressure, you need a new pump. They run around $375.
Have you pulled the T-stat housing? Did it have water in it? I had an issue with my first boat where the previous owner had not chased down the vanes from a totally destroyed impeller. They clogged up in what appeared to be an oil cooler or power steering cooler.
If I remember right, to pull the pump you first need to remove the belt(s) from the pulley, remove four allen head bolts holding the pump housing on. At that point you can get to the bolts holding the pulley to the crank shaft.
One thing you might try, pull the kill switch so the engine won't start, remove the outlet hose from the pump, then crank the engine. I've never tried this test, but I would assume it should pump water. Just a thought.
