Volvo MD2B - water in the oil after winterising

[WotSandbank]

Waterpump seals is one thing to consider esp if 10 years old.
For the reasons above you should/may notice water leaking from the pump before the water seal becomes so badly worn that water is forced into the engine via the oil seal.

If the water injection into the exhaust is not several inches above the water line you should have a raised loop in the hose leading to the injection point with an antisyphon valve at the highest point.
Check the valve for correct operation. A defective valve might explain water in the oil initially even if not how it may be getting in while recirculating.

The head gaskets are a possibility. Dont rush in to change these. They cost an arm and a leg so check cheaper things first.

If your engine has brass drain cocks ( or plugs) on the cylinder blocks perforation of the cylinder wall due to electrolytic action may be a possibility. It can happen, I understand, to the liners in an MD11 but I do not know if it happens to an MD2B

You may not have got rid of all the water when you drained the old oil. What you are seeing now may be water that remained after draining the oil esp if you sucked it out via the dipstick fitting rather than via the sump drain plug.
I'd feel inclined to flush the engine with the cheapest engine oil that you can find . ( Asda ?)

You dont say if you have the manuals. If not you can find the Owners manual on VP's website http://www.volvopenta.com/volvopent...lication_search/pages/publication_search.aspx
and the workshop manual at http://www.bluemoment.com/downloads.html

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Thanks VicS yes i have manuals both paper and electronic. I spoke to a friendly marine engineer i use sometimes and he said the seals were a good starting point. He felt the back syphoning was unlikely although he did say a lot of folk put buckets above the engine (usually in the cockpit) and after the engine is stopped it continues to syphon and eventuall can fill up the water jackets until it reaches the manifold and then into the engine. So if I find the water seals are ok this could explain the water ingress. Although the bucket I slung over the transom was probably below the engine, the 10ft length of pipe was not. He thinks this wouldnt have caused it but on the other hand may just.

He did say with new oil it diesnt take much to emulsify it. We shall see

 

[WotSandbank]

My MD2B had the water pump seals changed by previous owner some months before I bought the boat. One month after buying the boat I found the engine full to the brim with emulsified oil.

Problem was previous owner had damaged the seals when replacing them and put them back to back so he had blocked the drain hole. Sometimes the drain hole gets blocked up and you would have same problem.

Easy fix for the water pump but i opened the crankcase plates and dried out all the water. Bad news was that the engine was never the same again but it was rubbish in the first place.

John

Well here's hoping a serious flush out after changing my water pump seals does the job. My engine was running quite well.

 

[david_bagshaw]

could there be frost damage allowing water into the crankcase?,or with the hotter water , it has washed a hole somewhere.


we had a stainless exhaust box which only seaped until the engine was run on fresh water on lay up. then it leaked bigstyle.

 

[Bilgediver]

he did say a lot of folk put buckets above the engine (usually in the cockpit) and after the engine is stopped it continues to syphon and eventuall can fill up the water jackets until it reaches the manifold and then into the engine. So if I find the water seals are ok this could explain the water ingress. Although the bucket I slung over the transom was probably below the engine, the 10ft length of pipe was not. He thinks this wouldnt have caused it but on the other hand may just.

He did say with new oil it diesnt take much to emulsify it. We shall see

If you had your water supply from a hose or from a bucket mounted higher than the exhaust then this is most certainly the problem as the water can flow through the pump. A good flush out will be OK and then well oil the valves and seats via the inlet ports .

I have seen many folk fill their engines in this way and it is easily done. If oiled and well run after flushing then usually no permanent damage.

 

[pampas]

the reason I asked about your method of obtaining the water supply was because I have seen many get water into their engines by coupling to a mains hose, rune to tap,turn on water then get back start engine, Time taker fron tap to start has flooded the exhaust system causing your problem.

 

[WotSandbank]

could there be frost damage allowing water into the crankcase?,or with the hotter water , it has washed a hole somewhere.


we had a stainless exhaust box which only seaped until the engine was run on fresh water on lay up. then it leaked bigstyle.

Thanks for that: I don't think the engine got hot enough for this and no frost damage I think as we have had very little down on the south coast yet.

 

[WotSandbank]

the reason I asked about your method of obtaining the water supply was because I have seen many get water into their engines by coupling to a mains hose, rune to tap,turn on water then get back start engine, Time taker fron tap to start has flooded the exhaust system causing your problem.

yes I am beginning to think this is what I've done even though I had the bucket below the water line, I think the pipe had enough water in it to fill the water jackets and hence back into the cyclinders.

By the way I didn;t have mains water running, just a bucket filled to the top. But even so I think you have a point.

 

[WotSandbank]

If you had your water supply from a hose or from a bucket mounted higher than the exhaust then this is most certainly the problem as the water can flow through the pump. A good flush out will be OK and then well oil the valves and seats via the inlet ports .

I have seen many folk fill their engines in this way and it is easily done. If oiled and well run after flushing then usually no permanent damage.

Thanks bilgedriver. That gives me hope. I am going to change the water pump seals and service it so there's no danger from that tomorrow (Tuesday). Then flush it through a number of times with flushing oil until I have good old black oil again and then pray! This time of course I shall get the bucket below the engine and/or at least turn off the water as I stop the engine hopefully preventing any syphoning...

I shall report back.

 

[Stu Jackson]

Thanks bilgedriver. That gives me hope. I am going to change the water pump seals and service it so there's no danger from that tomorrow (Tuesday). Then flush it through a number of times with flushing oil until I have good old black oil again and then pray! This time of course I shall get the bucket below the engine and/or at least turn off the water as I stop the engine hopefully preventing any syphoning...

I shall report back.

That's a good plan.

You might be interested in this video. The concept is to have the bucket above the engine, drain the bucket and turn the engine OFF. Not too hard to do.

Good luck.

http://forums.catalina.sailboatowners.com/showthread.php?p=873073&highlight=winterizing

 

[david_bagshaw]

Thanks for that: I don't think the engine got hot enough for this and no frost damage I think as we have had very little down on the south coast yet.

doesnt need to get hot, the fresh water disolves the salt! the water in my case was ambient tank water, with the engine at just idle. 6cyl sabre.

 

[WotSandbank]

update

Many thanks to all who helped and contributed to this thread. Just an update on what happened.

Before anything I duly replaced the oil seals on the water pump which seemed ok although one was leaking a little. The holes were clear but no evidence of dripping water. I replaced the impeller for the heck of it.


Then:
1)Removed the oil strainer and drained all the 'mayonnaise' oil without starting the engine.
2) Removed the new 'mayonnaise filled' oil filter and replaced it with the old filter which just had old oil in it.
3) Added about 2 ltrs of old dregs oil (this is clean oil but remainders in various cans) that was suitable and ran the engine till warm.
4) Drained all this oil and added another 2 litres of dregs oil and added a can of Wynns Diesel engine flush. Ran the engine for 15 minutes.
5) Drained all the oil and added 2 ltrs of dregs oil and another can of Wynns Diesel engine flush. Ran engine for 15 minutes.
6) Drained all the oil, added 3.5 litres of fresh correct oil and changed the oil filter for a new one. Ran the engine for 2 hours.

Luckily she is fine. I think it takes more than syphoning a bit of fresh water into the engine to kill it!

My conclusion is that I did indeed allow the water to syphon back into the engine by having the feed water pipe too high. That coupled with possibly a faulty water pump seal was enough to to the damage.

Lesson learnt!

 

[VicS]

Thanks for reporting back.
Glad all sorted and no permanent damage done.

 

[Jcorstorphine]

Good to hear from you

Glad to hear your engine is running well, also good of you to give us all an update. We all live and learn from others experiences.

Regards

John, (ex MD2B owner)