water in engine oil

[Spirit (of Glenans)]

Links to tractors are irrelevant. The OP has a different engine that's also been marinised.

He's also stated that the coolant level does not change, in which case the water in the oil must be saltwater. He needs to check heat exchangers and the water pump.

He does say it's a Kubota.

 

[coopec]

Links to tractors are irrelevant. The OP has a different engine that's also been marinised.

He's also stated that the coolant level does not change, in which case the water in the oil must be saltwater. He needs to check heat exchangers and the water pump.

Links to tractors are irrelevant. The OP has a different engine that's also been marinised.

He's also stated that the coolant level does not change, in which case the water in the oil must be saltwater. He needs to check heat exchangers and the water pump.

There are parts that are common to Kubota Beta marine engines and Kunota beta tractor engines that could cause water leaks

Why would you need to check the heat exchanger? (I'm sure my marinsed Perkins has a separate oil cooler but that is not to say a Beta marine engine doesn't have a separate compartment in the engine water coolant heat exchanger. I would find that quite strange. But.....

Why check water pump? (I'm not familiar with the marinised Kubota Beta 25 hp motor)

The Borg Warner gear box has a separate heat exchanger but that wouldn't affect the engine oil.

 

[Tranona]

There are parts that are common to Kubota Beta marine engines and Kunota beta tractor engines that could cause water leaks

Why would you need to check the heat exchanger? (I'm sure my marinsed Perkins has a separate oil cooler but that is not to say a Beta marine engine doesn't have a separate compartment in the engine water coolant heat exchanger. I would find that quite strange. But.....

The Borg Warner gear box has a separate heat exchanger but that wouldn't affect the engine oil.

The question was whether water can get from the saltwater pump into the oil in the sump. The answer is yes because the pump is gear driven and the drive shaft has seals that prevent water from going one way and oil going the other. These pumps are not used on Kubota engines in tractors (which is what Paul was alluding to). In fact the make of engine is largely irrelevant as most marinisations (but not all) use the same type of gear driven pumps. Equally it has nothing to do with the heat exchanger or any oil cooler as the Beta does not have one.

In practice it is rare. The failure is more commonly of the first seal in the shaft behind the impeller which is exposed to seawater that can contain abrasive material causing wear on the shaft and water getting past. There is a witness hole in the housing between this and the oil seal and a sign of failure is water dripping out. For obvious reasons there is no such hole aft of the oil seal.

 

[vyv_cox]

The question was whether water can get from the saltwater pump into the oil in the sump. The answer is yes because the pump is gear driven and the drive shaft has seals that prevent water from going one way and oil going the other. These pumps are not used on Kubota engines in tractors (which is what Paul was alluding to). In fact the make of engine is largely irrelevant as most marinisations (but not all) use the same type of gear driven pumps. Equally it has nothing to do with the heat exchanger or any oil cooler as the Beta does not have one.

In practice it is rare. The failure is more commonly of the first seal in the shaft behind the impeller which is exposed to seawater that can contain abrasive material causing wear on the shaft and water getting past. There is a witness hole in the housing between this and the oil seal and a sign of failure is water dripping out. For obvious reasons there is no such hole aft of the oil seal.

See my post#6 and link. I discuss Bukh as that's what I know, not certain then that OPs engine was the same.

 

[Tranona]

See my post#6 and link. I discuss Bukh as that's what I know, not certain then that OPs engine was the same.

Yes, saw that - just wanted to make clear that the pump arrangement is common in marine versions and not found on tractor engines.

 

[PaulRainbow]

He does say it's a Kubota.

Yes, but it isn't in a tractor. It's marinised and the coolant level doesn't change, so the leak must be from the raw water side.

 

[PaulRainbow]

There are parts that are common to Kubota Beta marine engines and Kunota beta tractor engines that could cause water leaks

Not if the fresh water coolant level remains constant.

Why check water pump? (I'm not familiar with the marinised Kubota Beta 25 hp motor)

See post #6

 

[PaulRainbow]

duplicate

 

[pandos]

The question was whether water can get from the saltwater pump into the oil in the sump. The answer is yes because the pump is gear driven and the drive shaft has seals that prevent water from going one way and oil going the other. These pumps are not used on Kubota engines in tractors (which is what Paul was alluding to). In fact the make of engine is largely irrelevant as most marinisations (but not all) use the same type of gear driven pumps. Equally it has nothing to do with the heat exchanger or any oil cooler as the Beta does not have one.

In practice it is rare. The failure is more commonly of the first seal in the shaft behind the impeller which is exposed to seawater that can contain abrasive material causing wear on the shaft and water getting past. There is a witness hole in the housing between this and the oil seal and a sign of failure is water dripping out. For obvious reasons there is no such hole aft of the oil seal.

Op might want to have a good look for the witness hole, it may have been painted over or caked with crud so that the seawater is caused to pass beyond the second seal. It may also be that replacement seals may have been fitted incorrectly, so that the weep hole is blocked.

 

[mashford]

problem sorted thanks guys bit more investigation revealed shelf in rear locker had collapsed during heavy weather on last trip ouy allowing extremely heavy toolbox to squash exhaust hose and restrict water outlet have rerouted hose and moved shelf water was obviously entering through exhaust valve when shut down as removal of elbow resulted in water running out of hose just need to flush engine
thanks for your assistance with this problem