saltshaker1
Recruit
- Joined
- Jul 5, 2009
- Messages
- 1
RE: Mercruiser manifold and riser overheating
chevy mercruiser
5.7 liter v8 350
2002
Alpha 1
Hi I have an issue with one of my left manifolds getting hot. This is an open system and is cooled by saltwater. I have done the following:
1. Heads shaved and motor reassembled due to an issue that appeared like water and gas was mixing and the engine shutting off. I dismantled the engine, removed the heads. I sent them to a machine shop, they saw the left head was a little warped and cut both of them. I reassembled with all new marine gaskets. (Note the left side has the manifold that heats up)
2.I replaced the Outdrive raw water pump impeller looked good but replaced it anyway.
3. I removed the riser-spacer- and manifold. I disassembled them and ran the power washer through the holes to clear out any flake. Very minor rust came out. I then put muriatic acid in both the riser and manifold and flushed it away. I reassembled with all new gaskets. I replaced them with the same type of gaskets they had before. The lower unit had the gasket that has a pin hole on two areas, the spacer on the top where it meets with the riser does not all 4 holes are opened.
4.I checked the thermostat and it appears like its opening. The water hoses do not have a tremendous amount of water flowing through them. I filled up a container attached a hose to it and put the outdrive into it. The impeller appears to suck water fine. I noticed that the water that deposits from the outside right side (inside left manifold that heats) is coming out with the same pressure as the other but throwing out hotter water.
The motor temperature gauge shows the motor warming fine (not overheating).
I checked the thermostat and the housing and it appears to be ok. I plan to replace it with an older housing system that has more hoses. I will also try to change the water pump though it looks fine.
If anyone has any other ideas or have resolved similar instance please give me guidance. Thanks
chevy mercruiser
5.7 liter v8 350
2002
Alpha 1
Hi I have an issue with one of my left manifolds getting hot. This is an open system and is cooled by saltwater. I have done the following:
1. Heads shaved and motor reassembled due to an issue that appeared like water and gas was mixing and the engine shutting off. I dismantled the engine, removed the heads. I sent them to a machine shop, they saw the left head was a little warped and cut both of them. I reassembled with all new marine gaskets. (Note the left side has the manifold that heats up)
2.I replaced the Outdrive raw water pump impeller looked good but replaced it anyway.
3. I removed the riser-spacer- and manifold. I disassembled them and ran the power washer through the holes to clear out any flake. Very minor rust came out. I then put muriatic acid in both the riser and manifold and flushed it away. I reassembled with all new gaskets. I replaced them with the same type of gaskets they had before. The lower unit had the gasket that has a pin hole on two areas, the spacer on the top where it meets with the riser does not all 4 holes are opened.
4.I checked the thermostat and it appears like its opening. The water hoses do not have a tremendous amount of water flowing through them. I filled up a container attached a hose to it and put the outdrive into it. The impeller appears to suck water fine. I noticed that the water that deposits from the outside right side (inside left manifold that heats) is coming out with the same pressure as the other but throwing out hotter water.
The motor temperature gauge shows the motor warming fine (not overheating).
I checked the thermostat and the housing and it appears to be ok. I plan to replace it with an older housing system that has more hoses. I will also try to change the water pump though it looks fine.
If anyone has any other ideas or have resolved similar instance please give me guidance. Thanks