Raw water in Oil

[shamrock]

So, I have had some issues with a universal 5424 this year. First, the speed lever on the injector pump became stuck in the stop position. I cleaned it up and lubricated and got about 20 good hours out of the engine. Then I noticed some minor hunting which turned into significant hunting.

I just pulled out the injector pump and noticed grey goop all over the place. I immediately emptied the crankcase to find a bit of clear water followed by milky oil. I filled the crankcase with new oil, cranked a bunch of times and am currently emptying that oil as well.

I am trying to determine the cause of the water and have read about head gaskets or raw water pump.

If it is definitely raw water, can I rule out the head gasket since it is a fresh water cooled engine?

I also trying to understand how water can enter the engine through the water pump and how can I test if this is the case?

[noelex 77]

Don't forget internal corrosion in the exaust elbow. A common cause of raw water in the oil and probably the easiest to check.

[delmarrey]

What makes you think it's raw water? The heat exchanger would have to be leaking and get into the fresh water which could get into the engine through a bad head gasket.

On yanmars the raw water pumps are hooked to the timing case and can possibly leak into the crankcase through the timing gear case if the seals get really sloppy, don't know about universals. But it wouldn't be much if so.

[delmarrey]

Originally Posted by noelex 77

Don't forget internal corrosion in the exaust elbow. A common cause of raw water in the oil and probably the easiest to check.

In this case it would have to pass thru the valve guides or pass the piston rings, but most likely would seize up the motor if it sat for awhile.

[noelex 77]

Originally Posted by delmarrey

In this case it would have to pass thru the valve guides or pass the piston rings, but most likely would seize up the motor if it sat for awhile.

I have only seen it happen on two engines, but one was mine. I assumed the salt water could get past the worn valve guides of an older engine reasonably easily, but I defer to your much greater knowlege of all things diesel.

The water, and a lot of it, did appear in oil very rapidly in my case so thinking about it perhaps the piston rings broke on the final cylinder. Probably following corrosion from the salt water.
The engine concerned was scrapped so I never got full detail of the damage.

The engine was running fine before the catastrophic failure, appart from a very occasional refusal to turn over on starting, which was put down to an electrical problem, but in retrospect was probably hydraulic lock. Interestingly the engine could be turned over by hand, which suggests the rings were not sealing well in that cylinder.

[shamrock]

The reason I think it's raw water is when I started draining it, the first thing that came out was. I tasted salt water. If it was fresh water, I would have seen antifreeze, no?

For it to be leaking through the exhaust elbow, I agree that it wuld have to go travel aroundthe piston rings and I would have experienced some hydro lock, which results in very hard starting and starter failure.

Am I correct in thinking that it would not be a head gasketif it is salt water? I also read salt water can enter through an oil cooler, but I don't think I have one.

What is the best way to test the exhaust elbow?

Thank you!

[westwinds]

Water gets by piston rings. I have seen that with blown head gaskets and cracked heads. Do you have antifreeze in the engine? If you do, you should see the dye in the water that came off the bottom of the crankcase. From an auto parts store, you can get a testing device that detects carbon dioxide in the coolant. You hook it to the place where you put antifreeze water mixture into the engine, run the engine and see if the liquid in the device turns color. If no color change, then you know it is not a cracked head, blown head gasket, cracked cylinder wall. An engine will usually appear to overheat when exhaust gets into the cooling system. Here is the engine manual: http://www.ewmanchester.com/CalDocs/Universal%20Diesel_5411_5416_5424_5432_Owners%20Ma nual.pdf
Go down to page 37 as numbered in the manual pages for a diagram of the cooling system. See page 34 for diagram of raw water pump. It appears to me the pump is bolted onto the engine. That is the likely way for raw water to get into the crankcase, through a leaking seal on the raw water pump directly into the crankcase. If the seal is bad, the bearing is usually bad. The bad bearing can cause the seal to fail.

[delmarrey]

Originally Posted by westwinds

It appears to me the pump is bolted onto the engine. That is the likely way for raw water to get into the crankcase, through a leaking seal on the raw water pump directly into the crankcase. If the seal is bad, the bearing is usually bad. The bad bearing can cause the seal to fail.

From the design I would say that is possible. At least Yanmar has an air gap between the pump and motor case. The gap on this pump seems minimal. See link>>>> Universal 5432 raw water pump capacity

Over!

[shamrock]

Thanks, I do have antifreeze in the water, but did not see any sign of it in the water that came from the crank case.

I have removed the water pump and will also inspect the exhaust elbow to see if that could be it.

Thank you!

[athene]

Before you get too carried away, have you considered the most obvious cause, namely a blockage in or failure of the exhaust siphon break? In that event, you will get raw water sucked back into the engine every time you stop it, with resultant milky oil etc.

[shamrock]

I hear you, Athene, salt water in the cylinders would cause hydro lock and seize the engine pretty quickly though, right? You would notice it at start up if there was water in the cylinders. It also produces steam in the exhaust, I think. I will definitely check on it. Do I pull the exhaust hoses off the elbow and look inside?

I pulled off the water pump today and it looked like salt water had penetrated the seals and could have gotten into the crankcase that way, I will order a new assembly tomorrow.

I put the injector pump back in and started her up with new oil (after flushing a few times) and no water pump. The engine ran perfectly until it warmed up a bit, then I experienced a similar hunting problem although the motor runs perfectly under 1500 RPMs.

I'm thinking I need to pull out the governor and at east clean it up. Does anybody know how to access the governor? Under the throttle lever are two bolts and two nuts on studs and it looks like it would pull out like the injector pump, but I thought it would be prudent to see if anybody had any experience here before I tried it.

Thanks

[delmarrey]

Goto page 15 in this manual>>>>> http://www.ewmanchester.com/CalDocs/...24_Service.pdf

[athene]

If it is your siphon break, it would indeed make your engine difficult to start, but not necessarily seize it, since you're only talking about a small amount of water. We had this problem in 2000 and the engineer we called in only pinpointed it by removing one of the injectors, running the engine on just three cylinders and then stopping it, when you could see through the injector hole the seawater backing up into the cylinder. Perhaps an easier way, though, is to remove the siphon break and connect it up via a couple of spare hoses to any suitable pump and then run water through it to see if breaks the flow when you stop. If it continues flowing, then it's faulty and that might be the source of your problem. Another thing to look at is your exhaust waterlock, because if it hasn't got the capacity your exhaust system calls for, then that's another way raw water can back up into the engine.

[Sheepshank]

I just installed a new to me yanmar 3gm30f .Runs great but water pump was leaking a bit.Should i be worried about water intrusion into the oil also,oil looks good now.Plan on rebuilding water pump next time I am at the boat,but would like to move the boat a couple miles to another location first.Would this be advised against?

[gjordan]

Good luck getting the grey goop out of your engine. I rebuilt a diesel that had been run for a while with water in the oil, and that grey goop was almost like an uncured epoxy. Getting it out of all of the small oil passages was the really hard part. _____Grant.