harleyfool
Seaman Apprentice
- Joined
- Jun 7, 2009
- Messages
- 35
2000 - Volvo 4.3 GL - SX-M drive
To summarize (1) After 2 1/2 cruise dragged boat home and tried to flush with muffs on. No water return. Checked impeller and found it was damaged. Replaced. Removed thermostat housing. No obvious impeller parts. Had a spare thermostat so replaced. Restarted boat and runs hot to 200+ degrees. Hose from thermostat housing to water pump is warm. Hoses to manifolds cold.
(2) Took hoses off sea pump and flushed both ways. Rechecked impeller = OK. Took thermostat housing off. Took out "new" thermostat and placed in hot water. It opened. Checked all ports = no debris. Removed all attached hoses and no debris. Took hoses of left and right manifolds. Repeatedly flushed manifolds = good return out the stern drive. Also let the manifold back drain. Removed the water pump. Spins freely. Unable to visualize fins. Flush the block thru the two ports on the front of the block to which the water pump attaches. Reassemble and STILL RUNS HOT to 200+ degrees.
(3) Remove thermostat and restart boat. Thermostat max's out at 140 degrees. Large hose from thermostat housing to water pump is now cool not hot as previously. Manifolds/risers slightly warm to touch - previously cold.
OK, so what gives? Defective thermostat. Damaged water pump??
Any thoughts???
To summarize (1) After 2 1/2 cruise dragged boat home and tried to flush with muffs on. No water return. Checked impeller and found it was damaged. Replaced. Removed thermostat housing. No obvious impeller parts. Had a spare thermostat so replaced. Restarted boat and runs hot to 200+ degrees. Hose from thermostat housing to water pump is warm. Hoses to manifolds cold.
(2) Took hoses off sea pump and flushed both ways. Rechecked impeller = OK. Took thermostat housing off. Took out "new" thermostat and placed in hot water. It opened. Checked all ports = no debris. Removed all attached hoses and no debris. Took hoses of left and right manifolds. Repeatedly flushed manifolds = good return out the stern drive. Also let the manifold back drain. Removed the water pump. Spins freely. Unable to visualize fins. Flush the block thru the two ports on the front of the block to which the water pump attaches. Reassemble and STILL RUNS HOT to 200+ degrees.
(3) Remove thermostat and restart boat. Thermostat max's out at 140 degrees. Large hose from thermostat housing to water pump is now cool not hot as previously. Manifolds/risers slightly warm to touch - previously cold.
OK, so what gives? Defective thermostat. Damaged water pump??
Any thoughts???