Problems started two weeks ago with my boat:
Mercruiser 5.7L with Alpha One lower unit, carbureted.
Launched boat and it wouldn't start. Acted like dead battery so I had a gentleman give me a jump. His boat was running and had four batteries. When I tried to jump it, it made noise like the starter was bad, clicked but wouldn't turn over at all. Replaced starter with a new one and it started like a champ in the driveway. The next day at the boat launch I again had trouble when trying to start the boat, starter turned over and made a bad grinding sound. Pulled boat home and pulled out new starter to find that it had broken the aluminum nose cone casting off. Suspected hydrolock condition at the docks. Changed the oil and found about a quart of water in the oil, also changed the spark plugs and I also pulled the manifolds and heat risers off and checked the flappers. Installed new manifold gaskets and heat riser gaskets, but not the manifolds themselves, flappers were fine. Boat started great after this maintenance. However, a week later when I tried to start the boat in the driveway, same trouble with boat starting, this time it was just a slow crank problem and eventually the boat turned over and started.
I then took the boat out on the lake last night and found that I still am getting water into the oil pan. So this morning I did a compression test and a voltage drop test to see if my starting problem was isolated from the water in the oil problem. However I suspect that the water problem is causing difficulty starting; perhaps having too much oil/water in the engine is causing high compression at startup? I have not seen any water coming out of the cylinders when I remove spark plugs.
Compression (dry) test results: (conducted multiple times with two different gauges because I didn't believe they could all be 160 myself.)
Cylinders 1, 3, 5, 7 were 160, 160, 160, 160 psi respectively
Cylinders 2, 4, 6, 8 were 170, 160, 160, 160 psi respectively
Questions: Is there any possibility that I have a bad head gasket with these compression test results? Or a cracked block? I'm think no, however I am not a schooled engine mechanic and would like some opinions to help find where I am getting water into the engine oil. I suspect I need to do some sort of leak down test on the manifolds. But if the manifolds were leaking, wouldn't I have water in the cylinders when I pull the spark plugs?
I have done a voltage drop test on the starting system and here is what I found to try and isolate a possible starting problem that may or may not be related to my water in the oil problem.
Starter circuit
Battery available voltage: 12.75volts (not cranking)
Battery available voltage while cranking: 11.55volts
Battery terminal voltage to the starter housing: 11.35volts
Is the battery okay? Is the 11.35 volts available at the starter while cranking not enough?
Voltage drop on the positive side of starter circuit:
Battery positive post to the battery terminal post on starter: 0.355volts
checks okay as max drop should not exceed 0.6 volts
Voltage drop on negative side of starter cicuit:
Starter housing to the negative Battery terminal: 0.29volts
checks okay as it should not exceed 0.30volts
After these two different tests I have no idea where the water is coming from. The starter voltage appears to be okay, although I am not 100 percent sure that 11.35 volts available at the starter while cranking is enough.
Where is my water coming from? Any suggestions. Keeping in mind that the exhaust flappers are in place and intact and appear to be in good condition. Compression tests good. Difficulty in starting comes after boat sits for a week in the driveway. I just dont get it at this point and dont have any idea as to where to look next.
Mercruiser 5.7L with Alpha One lower unit, carbureted.
Launched boat and it wouldn't start. Acted like dead battery so I had a gentleman give me a jump. His boat was running and had four batteries. When I tried to jump it, it made noise like the starter was bad, clicked but wouldn't turn over at all. Replaced starter with a new one and it started like a champ in the driveway. The next day at the boat launch I again had trouble when trying to start the boat, starter turned over and made a bad grinding sound. Pulled boat home and pulled out new starter to find that it had broken the aluminum nose cone casting off. Suspected hydrolock condition at the docks. Changed the oil and found about a quart of water in the oil, also changed the spark plugs and I also pulled the manifolds and heat risers off and checked the flappers. Installed new manifold gaskets and heat riser gaskets, but not the manifolds themselves, flappers were fine. Boat started great after this maintenance. However, a week later when I tried to start the boat in the driveway, same trouble with boat starting, this time it was just a slow crank problem and eventually the boat turned over and started.
I then took the boat out on the lake last night and found that I still am getting water into the oil pan. So this morning I did a compression test and a voltage drop test to see if my starting problem was isolated from the water in the oil problem. However I suspect that the water problem is causing difficulty starting; perhaps having too much oil/water in the engine is causing high compression at startup? I have not seen any water coming out of the cylinders when I remove spark plugs.
Compression (dry) test results: (conducted multiple times with two different gauges because I didn't believe they could all be 160 myself.)
Cylinders 1, 3, 5, 7 were 160, 160, 160, 160 psi respectively
Cylinders 2, 4, 6, 8 were 170, 160, 160, 160 psi respectively
Questions: Is there any possibility that I have a bad head gasket with these compression test results? Or a cracked block? I'm think no, however I am not a schooled engine mechanic and would like some opinions to help find where I am getting water into the engine oil. I suspect I need to do some sort of leak down test on the manifolds. But if the manifolds were leaking, wouldn't I have water in the cylinders when I pull the spark plugs?
I have done a voltage drop test on the starting system and here is what I found to try and isolate a possible starting problem that may or may not be related to my water in the oil problem.
Starter circuit
Battery available voltage: 12.75volts (not cranking)
Battery available voltage while cranking: 11.55volts
Battery terminal voltage to the starter housing: 11.35volts
Is the battery okay? Is the 11.35 volts available at the starter while cranking not enough?
Voltage drop on the positive side of starter circuit:
Battery positive post to the battery terminal post on starter: 0.355volts
checks okay as max drop should not exceed 0.6 volts
Voltage drop on negative side of starter cicuit:
Starter housing to the negative Battery terminal: 0.29volts
checks okay as it should not exceed 0.30volts
After these two different tests I have no idea where the water is coming from. The starter voltage appears to be okay, although I am not 100 percent sure that 11.35 volts available at the starter while cranking is enough.
Where is my water coming from? Any suggestions. Keeping in mind that the exhaust flappers are in place and intact and appear to be in good condition. Compression tests good. Difficulty in starting comes after boat sits for a week in the driveway. I just dont get it at this point and dont have any idea as to where to look next.
