Perkins Engine - Raw Water in Crankcase

[Troubadour52993]

Some of the oil coolers are like the transmission coolers, straight raw water to oil. I like the original Serck oil cooler that is fresh to oil, but they are hard to get and major $$ in the US.

Not sure what type water pump">raw water pump this is, but both my Perkins have Jabsco raw water pumps where the pump leaks outside the engine if the drive shaft seal leaks. It would then have to get past the bearing/seal to get into the gear drive portion of the pump.

Exhaust line head still best explains why it floods with valve open but not with valve closed...

[Stillraining]

Originally Posted by never monday

read all of the original post......He has to close the gate valve and raw water after shutting the engine down to prevent water coming in). This last time, they had an issue and forgot to close the valves which stayed open overnight - flooded the next morning.

AH!...I did miss that Thanks NM...But that doesn't help me too much...Well maybe a tad...in that if, it is a gear driven pump, (OP can you please tell us that?) and its below water level the constant head pressure on failed seals would do it...but I would still think it would get water past those seals while it was running as well, not when just stopped..I have seen funny things like that happen though so you could be right.

If it is indeed comming through the exhaust, the lack of hydraulic lock still has me stumped though....I cant wait for this one to show itself..

[Longtall]

Recently this happened to me. I own a Marinised Kubota 4 cyl 30 hp diesel and after copping some serious chop up the stern while tied up on an exposed jetty I discovered for the first time raw water in the sump. No oil cooler, impeller etc in good condition but no loop above water line in exhaust and possibly a leaky water trap between the engine and outlet. We are not just talking a few cupfuls here, this was a litre or more that had entered the sump via the exhaust whilst the engine was off. All the experts couldn't agree on how it got in there, however one plausable theory is that with the rings at rest there is much more of a gap between themselves, the grooves they sit in and the cylinder walls and if the water did come in through an open valve then it might find its way past them and then into the sump. This has only happened one time and with repeated oil and filter changes was able to clear most of the water out.



This is the only explanation that has made sense so far. Not sure about the volume of water that could past in just one cylinder though.
Cheers
Colin

[Saltyrope]

Raw water in crankcase..... This is an old post so I wonder what the problem was, having not read all the posts yet. Immediate thought was that the 'muffler' was not doing its job if one of those with a one way valve in it or the wet box water lock was no longer working from either lack of pressure build up from a leaking joint or it had developed a 'by pass' internally and was, in effect, not keeping the box pressurized at its dam open point (just above the bottom) and so became just a wet box full of water, ready to slop back up into the exhaust header pipe.


If anyone knows what the solutution was I would be interested to read about it.