Somehow I got saltwater in my Yanmar 2GM20F engine. Took out the engine and had it overhauled and re-installed by a marine mechanic. He started engine and ran for 30 minutes and he said it was ok. When I returned to boat a week later I notice the crankcase was full of saltwater. Does anyone know what can cause?
Saltwater in the Yanmar engine of my 29' Hunter, why?
- Thread starter eagle366
- Start date
Is the raw water pump shaft driven or belt driven? If the lip seals fail it can allow sea water into the crankcase
Yes.. on 2 GM20F, salt water only able to get into engine from the exhaust riser elbow.. the elbow itself may have a hole that leaks salt water into the engine exhaust side.. or as others have said, water can back up if the anti syphon valve on the loop gets plugged. It is the little plastic thing on top of the little stainless loop on the back wall .. yours may look a little different but it should be in the line from the heat exchanger going to the exhaust elbow.
Highly likely this is seawater discharge/exhaust design or install issue. Consider this article. (While the narrative may not be crystal clear the concepts are obvious. Pay particular attention to spill over concepts. )
http://www.sbmar.com/articles/designing-a-marine-exhaust-system/
However - the motor evidently did not historically flood with seawater and assuming no changes in pipe and tube otherwise - find out if the mixing elbow was replaced with brand new. If not - replace it now pronto. The material price is under $200.
Meanwhile shut off the seawater intake - to- seawater pump through hull valve anytime you are not using the motor.
Charles
http://www.sbmar.com/articles/designing-a-marine-exhaust-system/
However - the motor evidently did not historically flood with seawater and assuming no changes in pipe and tube otherwise - find out if the mixing elbow was replaced with brand new. If not - replace it now pronto. The material price is under $200.
Meanwhile shut off the seawater intake - to- seawater pump through hull valve anytime you are not using the motor.
Charles
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If you are sure it is saltwater...
Shut you sea water sea cock NOW!
Remove the oil/water quickly and substitute your oil with diesel and bump the engine a few strokes to circulate the diesel. This will coat your pistons.
Your engine will hydrolock.
Jim..
Good choice of "pickling" agent.
By any method of pickling to prevent hydrolock, get the salt water out!
I had discovered saltwater in my oil (luckily in time). Since I was panicking, my son-in-law, the diesel mechanic, recommended diesel pickling (in a pinch). My engine now starts faster then my Ford Expedition.
I used this trick to test a sample of my foamy oil to verify saltwater.
https://www.amazon.com/Aquachek-Whi...6254478&sr=8-1&keywords=saltwater+test+strips
Good luck!
Jim...
It sounds like the vented loop is not working and siphoning water into the exhaust. Cleaning it is part of my spring commissioning. Jim, how did salt water find it's way into your engine?
Everything you've seen above, except don't put anything in the crankcase except engine oil. Change it and run for a few minutes to clean everything out. Drain and repeat several times over. Take the boat out for an hour or so under heavy load and do a final change. Salt water in the engine oil is not a good mixer.
One other thought is the elevation of your anti-siphon valve above your water line. Can't remember what the minimum height is, but you'll find it somewhere on here. Any chance the water line has crept up with a new heavy load.
Measure the water line using a clear vinyl tube - 1/4" - tapped into a thru hull and run over beside the anti-siphon valve.
Please report back on your findings as they very well may help someone else with a similar problem.
One other thought is the elevation of your anti-siphon valve above your water line. Can't remember what the minimum height is, but you'll find it somewhere on here. Any chance the water line has crept up with a new heavy load.
Measure the water line using a clear vinyl tube - 1/4" - tapped into a thru hull and run over beside the anti-siphon valve.
Please report back on your findings as they very well may help someone else with a similar problem.
Backwards from a incorrectly installed Dripless shaft seal purge line. ( for pictures
)http://forums.sailboatowners.com/index.php?threads/water-in-engine.175063/page-2#post-1253716
I got lucky and it only cost me an engine starter.
The mechanic in Tampa, was great on fixing shaft, cutlass bearing, and doing my Sea Trial, but he forgot about my Boats Waterline when he installed the Drip Less Purge.
The OP didn't say he had a dripless shaft seal.
Jim...
PS: The emergency diesel, as a pickling agent, saved my engine. Diesel is just low lubricity oil.