jim dozier
Lieutenant Commander
- Joined
- Jan 8, 2003
- Messages
- 1,970
Re: I need some help. Overheat alarm only @ WOT.
First let me say that I have never worked on your kind of engine, so most of what I'm suggesting is in general terms, (like my original post about the head gasket which it turns out you don't have). I know that it is important to keep exhaust out of the cooling water until it leaves the block. Areas where hot exhaust can enter the coolant are:<br />1. At the head gasket, not applicable here.<br />2. Between the water pump and the exhaust housing at the joint between the lower unit and the middle unit. If this area is not sealed properly exhaust can leak over to the water pump and get sucked into the water. Depending on the particular engine, some manufacturers require some sort of sealant there.<br />3. At the gasket beneath the powerhead.<br /><br />A separate issue. Higher than normal water pressures suggest a restriction at some point after the place where the pressure is measured, that is the water is getting in OK but not out OK. I have no idea what the proper water pressure for your engine is. You might try removing the lower unit again and clamping a garden hose on the water tube where it connects to the water pump and checking the flow out of the engine.<br /><br />I recommend again that you get an infrared point and shoot thermometer (Radio Shack $49.99) and find out once and for all if this engine is overheating.
First let me say that I have never worked on your kind of engine, so most of what I'm suggesting is in general terms, (like my original post about the head gasket which it turns out you don't have). I know that it is important to keep exhaust out of the cooling water until it leaves the block. Areas where hot exhaust can enter the coolant are:<br />1. At the head gasket, not applicable here.<br />2. Between the water pump and the exhaust housing at the joint between the lower unit and the middle unit. If this area is not sealed properly exhaust can leak over to the water pump and get sucked into the water. Depending on the particular engine, some manufacturers require some sort of sealant there.<br />3. At the gasket beneath the powerhead.<br /><br />A separate issue. Higher than normal water pressures suggest a restriction at some point after the place where the pressure is measured, that is the water is getting in OK but not out OK. I have no idea what the proper water pressure for your engine is. You might try removing the lower unit again and clamping a garden hose on the water tube where it connects to the water pump and checking the flow out of the engine.<br /><br />I recommend again that you get an infrared point and shoot thermometer (Radio Shack $49.99) and find out once and for all if this engine is overheating.