Oil in water intake hose

[rjamaro]

Hi redbeard,

My engine is cooled with sea water, I don't have a fresh water circuit. The hoses seem to be stiff. Yesterday a friend told me that eventually that the compression of the engine may be escaping through the head sending pressure and residues back and using the raw water system... For me at this moment it seems that I need to open it and do a proper maintenance on it. My big fear is that I found major issues on parts that are not in production and may be hard or impossible to find in the market.

[redbeard1]

Hello,


I wouldn’t open the engine yet. Adding to what Stu said, when dealing with mechanical stuff, it is good to approach the problem systematically.


Look up your engine on the following website
https://www.marinepartseurope.com/en...t-7742230.aspx


and print an image. Every time you have an idea of what could be causing the problem, try to follow the path and look for confirmation. For example, if the oily stuff you found in the strainer is from the engine, there should be stuff all along the yellow line and your oil level should be low.

Also keep in mind that the oil from the engine would need to go upstream against a current of water, through the impeller of the raw water pump (an intact impeller acts like a check valve so even when the engine is not running, it is difficult for fluid to flow upstream. Btw what was the condition of your impeller?) to finally reach the strainer. Is it possible? I don’t know enough to say it is impossible, but I would look for more likely options.


For example, if the oily stuff you found is residue from hose C, then you would expect to find the residue in the strainer, in hose B, and downstream. You would also expect water flow to be greatly reduced which could account for your engine stopping after X minutes of operation.


It appears your engine is from the early 80s. If that is the original hose, then it may very well need replacement. You could replace hose B and C, clean the strainer, and see if the residue returns. If it does not, then maybe you have your answer.



p.s. a quick glance at that website shows lots of spare parts are still available.

[rjamaro]

Thanks for all your support.

Yes, I need to have a sistematic approach, but I am also wanting to do a big and deep maintenance, maybe the engine after a good and deep maintenance will last more 30 years.

When I have it out of engine room I start debugging this engine

Thanks