5.7 Volvo cooling issues

Hello,

After a severe overheating event (my fault - should have replaced the raw water impeller), I replaced the cylinder heads, raw water pump impeller, bellows, manifold/elbow couplers, raw water pick up line in outdrive, thermostat, and water temp sensor. I removed as many impeller blades as could be found and back flushed the block from the block drains forward. The engine temp will quickly rise to 175 at idle and to climb to over 200 when I bring the boat up on a plane. There is no water in the oil and I have good water flow to the thermostat housing. I did the clear hose test from the outdrive and appear to have no major air leaks. The exhaust is clear of obstructions. I checked the gauge and temp sender and the gauge is accurate. Timing is correct. The only I have not done in to pressure check the block as I don't know how this is done. I am completely stumped. I really do not want to replace this engine until I know what the problem is.
Does anyone have any ideas? This 5.7 replaced the original 5.0 GL PBYC.

Regards,

Jim Callaghan

Re: 5.7 Volvo cooling issues

Ayuh,... My guess is the risers are plugged, not allowing the water Out...

Re: 5.7 Volvo cooling issues

Here is the Volvo overheat diagnosis file. http://www.4shared.com/file/50572185/e88f1d89/Volvo_Penta_Overheat_Diagnosis.html
It will show you how to find the problem.

Re: 5.7 Volvo cooling issues

Thank you for the link. I'm going out tomorrow to run the "in the water" tests.

Jim C.

Re: 5.7 Volvo cooling issues

What engine operating temps are considered "normal" when running a 160 degree thermostat? My gauge (which tested accurate) is reading around 175.

Jim