Have a 1978 aq120 volvo penta. I was out on mater when impeller quit ran engine hot. I shut down and was towed back. Installed new impeller and new thermostat, hoses. Ran engine in a big drum of water. The raw water pump is sucking in reverse.Not sucking water in it to the oil cooler, but pushing water back through. Checked water cooler for blown seal. Having pressure build up in cooling system. My opinion its a blown head gasket or worse. Any ideas besides what ive said. Thank you.
