Oil Leak

[Chuck]

I have 1988 Catalina 30 TR that has developed an oil leak. After two weeks of non-operation of the engine I found about a cup of oil leaked into the bilge. The leak appears to be coming from between the oil pan and the engine block, though I can't say for certain. I check the engine oil level before starting the engine or using it, but not after using the engine. Since I hadn't used the boat in two weeks I can't yet tell if the leak is a gradual slow leak or if it is worse when the engine is running. I have two questions:1. Does anyone know what the source of the leak might be?2. Also, the bolt heads for the oil pan, though very difficult to access, seem to be an odd size, possibly 13/32, not 1/2", 5/16 or any regular size. From your experience does this seem right? Could it be metric? I don't have a wrench to fit it.By the way, the engine is a Universal M-18, 2 cylinder, 14 horsepower.Any help would be greatly appreciated.

 

[Denny Fegan]

Check the pan

Chuck,The most common problem for a oil leak is that the water pump leaks and corrodes the front of the pan. If this is the cause you will have to take the bolts out of the coupling, remove the nuts from the motor mounts, put a 2X4 across the hatch and use a come-a-long to lift up the engine. You can then remove the oil pan and replace it.Best,Denny Fegan

 

[Jerry]

I have the same year boat tall rig M18 engine. Had oil leaking about the same amount. I found that some water leaking from around the water pump was getting on the oil dipstick tub and it had started to corrored till oil was leaking out. It was a real treat getting it out with the rusted bolts. But I also saw that their was corrossion around the pan where it mates to the block. So I replaced the pan. Problem solved.