Volvo Penta MD2B issue

[coworks]

Hello,
I have an issue with my Volvo penta MD2B. When I got this engine there was a problem with one cylinder, found a problem, diesel injection pump, fixed it. Then started it, for 5min was everything ok, but then started to raise rpm almost to maximum by it self. Oil was going together with water from exhaust. I could turn it off only with decompression and fuel cut off. Though might be problems with oil, too much of it and it's getting yo cylinders.
Changed the oil, oil filter, filled 3l new oil. Started it, ran perfect. Went for a test ride, was everything ok. Only some white smoke going from exhaust and no oil. But it ran like this for maybe one week max 6 hours and today same issue started. Raising rpm by it self while running on idle, brown smoke from exhaust and oil with water from exhaust. Engine is running even if fuel is cut off.
So, oil in cylinders?
What problem can it be?
Interesting thing that when I sucked the old oil, there was more than 4 liters of it and it was more like a water not oil, but black.
Can it be that water is getting into oil and when it gets too much of it that mixture is getting in cylinders?
Thank you in advance.
P.S. sorry for not the best English

 

[Assassin]

Diesel leaking into the sump which is then picked up by the engine and it runs on a mixture of sump oil and diesel.

This is usually an injection pump issue which is usually a leaking seal.

Water in the oil is a major issue and can be anything from a blown head gasket to an incorrectly seated liner, through to a cracked cylinder head or hairline crack in the engine block of cylinder liner; and it can be a combination of all the above.

 

[scottie]

Diesel leaking into the sump which is then picked up by the engine and it runs on a mixture of sump oil and diesel.

This is usually an injection pump issue which is usually a leaking seal.

Water in the oil is a major issue and can be anything from a blown head gasket to an incorrectly seated liner, through to a cracked cylinder head or hairline crack in the engine block of cylinder liner; and it can be a combination of all the above.

One of the most common reasons for water in oil on these engines is from the water pump seals failing along with a buildup of crud in the tell tale holes
If you have diesel in the oil you can smell it on the dipstick

 

[coworks]

So it might be diesel in oil? Because I think it will not run when fuel is cut off with mixture of oil and water, it should be diesel with oil to run it and hold high rpm?

 

[Bilgediver]

Hello,
I have an issue with my Volvo penta MD2B. When I got this engine there was a problem with one cylinder, found a problem, diesel injection pump, fixed it. Then started it, for 5min was everything ok, but then started to raise rpm almost to maximum by it self. Oil was going together with water from exhaust. I could turn it off only with decompression and fuel cut off. Though might be problems with oil, too much of it and it's getting yo cylinders.
Changed the oil, oil filter, filled 3l new oil. Started it, ran perfect. Went for a test ride, was everything ok. Only some white smoke going from exhaust and no oil. But it ran like this for maybe one week max 6 hours and today same issue started. Raising rpm by it self while running on idle, brown smoke from exhaust and oil with water from exhaust. Engine is running even if fuel is cut off.
So, oil in cylinders?
What problem can it be?
Interesting thing that when I sucked the old oil, there was more than 4 liters of it and it was more like a water not oil, but black.
Can it be that water is getting into oil and when it gets too much of it that mixture is getting in cylinders?
Thank you in advance.
P.S. sorry for not the best English

What you are describing is oil dilution of the sump oil by diesel oil. Ignore comments about water as the oil would be a creamy colour if it was a water problem.

If the oil level is noticeably rising when the engine is run then you have an excessive spill leakage from the Injector pump mounted on the rear top of the engine. There is always some leakage of the pump plungers as this is their means of lubrication.

It is possible you had major dilution due to the time the oil had run without change. It should be changed annually. Maybe there was still a major amount of diluted oil in the sump after pump out if you did not do a flush out.

The state of your exhaust suggests there are also problems in one or both cylinders regarding valve stem seals and guide clearances and or possible bore wear and maybe stuck oil control rings.

Beware the gloom and gloom stories you may hear, it is usually possible to get an MD2B running again with a few gaskets,stem seals and piston rings plus a little help from friends. The heads are easily removed and with them off the blocks can be lifted off to expose the pistons. I have seen boat owners get them back into service and then run for many years after no more than replacing seals gaskets etc and correctly dealing with the valves and seats. The manual will show what is required here and it is a bit more than just grinding with a wooden valved turner and paste as this will produce too wide a seat for long life.If there is major damage to a head or block then there could be a problem as new spares are unobtainable, however in the last 30 years I have only had the heads off.

In the short term monitor your oil level as I this is rising then get your fuel pump tested buy a local non marina based diesel injection specialist and carefully also remove and take your injectors for servicing. Remember the injectors sit in copper sleeves which are expanded into pockets in the heads and if they are moved during injector removal a water leak may develop from one or both ends of the sleeve. A request here may produce the correct removal tool.

 

[coworks]

What you are describing is oil dilution of the sump oil by diesel oil. Ignore comments about water as the oil would be a creamy colour if it was a water problem.

If the oil level is noticeably rising when the engine is run then you have an excessive spill leakage from the Injector pump mounted on the rear top of the engine. There is always some leakage of the pump plungers as this is their means of lubrication.

It is possible you had major dilution due to the time the oil had run without change. It should be changed annually. Maybe there was still a major amount of diluted oil in the sump after pump out if you did not do a flush out.

The state of your exhaust suggests there are also problems in one or both cylinders regarding valve stem seals and guide clearances and or possible bore wear and maybe stuck oil control rings.

Beware the gloom and gloom stories you may hear, it is usually possible to get an MD2B running again with a few gaskets,stem seals and piston rings plus a little help from friends. The heads are easily removed and with them off the blocks can be lifted off to expose the pistons. I have seen boat owners get them back into service and then run for many years after no more than replacing seals gaskets etc and correctly dealing with the valves and seats. The manual will show what is required here and it is a bit more than just grinding with a wooden valved turner and paste as this will produce too wide a seat for long life.If there is major damage to a head or block then there could be a problem as new spares are unobtainable, however in the last 30 years I have only had the heads off.

In the short term monitor your oil level as I this is rising then get your fuel pump tested buy a local non marina based diesel injection specialist and carefully also remove and take your injectors for servicing. Remember the injectors sit in copper sleeves which are expanded into pockets in the heads and if they are moved during injector removal a water leak may develop from one or both ends of the sleeve. A request here may produce the correct removal tool.

That's a perfect answer, thank you!