My MD 22 engine oil oil too clean !!

[patprice]

All very strange!

My Volve MD 22.

The oil does not turn black as a diesel motor is supposed to. Last oil change was 50 hours or 2 months ago. And the oil is like new on the dipstick.

Seriously, there is almost no blackening! Or for that matter little other discoloration.

Almost clear like a petrol engine.

And yes there is a full lot of oil in the engine! And the dipstick is long enough to get "wet".

Comments please.

[UNCIVILIZED]

Send it in for analysis & get expert feedback.

[Captsteve53]

If an oil is doing its job cleaning the engine, then it will be dirty when it is drained. In the case of diesel engines, the oil may look dirty within a few hours of operation. This indicates that the motor oil is keeping soot, dirt and other combustion contaminants in suspension. These will then be carried to the filter or removed from the crankcase when the oil and filter are changed. Good quality motor oils are formulated to hold these contaminants in suspension until the oil is drained when the oil and filter are changed.

Saying that if the engine is new or recently rebuilt then @ 50 hours running it could still be quite clean (as the engine is clean) depends on running conditions as well,

What is the oil make/ viscosity?

Cheers Steve

[patprice]

I do not know the oil make as I buy it from a charter company here in Greece. It is 15W40 and they buy it in bulk, 200 litre drums, and sell it in 4.5 litre containers. It has all the right specs for diesel use.

I do not feel there is anything untoward with the engine, or at least I hope. Has been this way for the last 4 years I have owned her. Runs well.

[Meacenas]

Oil for any IC engine is a lubricant to keep all those metal parts from rubbing each other. Oil also has a slight cooling property and it does carry minute amounts of soot and dirt to the filter where they are removed down to a micron level.
All bearing surfaces have a very thin oil film that separates the parts from each other, otherwise the metal rubbing together at high speed and high pressure would soon fuse together.
The oil gets black from the burned gas blowby of the combustion process. The piston rings (usually three, two sealing rings and a oil scraper) if they are doing their job correctly will prevent the burned gas from reaching the oil.
When the engine is new, the two cast iron seal rings will rub up and down on the cylinder walls and eventually match the wall very exactly through wear, ( part of the break-in process). The oil ring, ( which is actually two very thin rings with a separator) will do the same, but its job is the opposite, to keep the oil from the crankcase that is thrown up by the crankshaft as it rotates, from reaching the combustion chamber. Very tiny amounts of oil usually do find their way to the combustion chamber and a very tiny amount of combustion gasses will get past the sealing ring gaps and that is what makes your oil black. Its the burnt byproduct from the combustion chamber.
Your rings are doing an exceptional job of keeping the stuff out of the oil, thats good.
However, that does no preclude a problem and it could be elsewhere in the oiling system. It would still be a good idea to follow Uncivilized suggestion to get your oil analyzed to be sure.

[heywoodp]

I too have an MD22. My oil tends to stay nice and clean until around 75 hrs after which it slowly darkens. I change it every 200hrs.

[Cadence]

Originally Posted by patprice

I do not know the oil make as I buy it from a charter company here in Greece. It is 15W40 and they buy it in bulk, 200 litre drums, and sell it in 4.5 litre containers. It has all the right specs for diesel use.

I do not feel there is anything untoward with the engine, or at least I hope. Has been this way for the last 4 years I have owned her. Runs well.

If it has been that way for four years, if it ain't broke don't fix it. I think you should count your blessings.

[Elie]

Originally Posted by heywoodp

I too have an MD22. My oil tends to stay nice and clean until around 75 hrs after which it slowly darkens. I change it every 200hrs.

I have the same engine(MD22LA) and my oil is also very clean. I change oil at the end of each season after roughly 70 hours.
I alway presumed that the fact that the oil is not pumped through the dipstick but dumped like car engines by onscrewing a bolt at the bottom of the oil pan. So all the oil is drained along with any remnant sludge, something hardly possible if it is pumped. Old oil remaining into the bottom of the pan may explay its blackish color.

[Ken Z]

I have a 1999 ford f250 7.3 diesel , bought it new, has 80,000 original miles and use it to haul trailers. I have changed the oil every 2500 miles and the oil is gold until 2200 miles then gets a little color, relax, be happy, you have a good motor.😁

[SeaBreeze-1]

There are fuel filters available that look identical to oil filters and are much finer at filtering out contaminants. It's possible that you may have asked for an oil filter for your engine but was handed a fuel filter by mistake. It's not a real bad problem but should be changed before the filter clogs up and starts to obstruct the flow of oil. I have a Yanmar engine and the identical problem(?) happened to me. Found this out from a boat mechanic that had the same issue. Try swapping out for a new "Oil" filter and see if you can get the oil nice and black again.

[patprice]

Originally Posted by SeaBreeze-1

There are fuel filters available that look identical to oil filters and are much finer at filtering out contaminants. It's possible that you may have asked for an oil filter for your engine but was handed a fuel filter by mistake. It's not a real bad problem but should be changed before the filter clogs up and starts to obstruct the flow of oil. I have a Yanmar engine and the identical problem(?) happened to me. Found this out from a boat mechanic that had the same issue. Try swapping out for a new "Oil" filter and see if you can get the oil nice and black again.

Would a fuel filter fit?

[patprice]

Originally Posted by Ken Z

I have a 1999 ford f250 7.3 diesel , bought it new, has 80,000 original miles and use it to haul trailers. I have changed the oil every 2500 miles and the oil is gold until 2200 miles then gets a little color, relax, be happy, you have a good motor.😁

Music to my ears! Yes my motor is good.

[Captsteve53]

Many oil and fuel filters have the same thread so inadvertently can be swapped over, The fuel filters in the main have finer micron elements than an oil filter, yes a fuel filter could eventually block up, but many engines /filters have by a by pass in this event!

[patprice]

My filter is a MANN FILTER W917. An oil filter.

[Cadence]

I doubt you swapped filters. I don't by the theory of the oil should clean the engine it should lub. it as long as the engine it tight, HD oil may clean a little and keep it tight. As said earlier count your blessing your engine is in good shape. If the oil should be dirty where it yours carbon going? Out the exhaust and not past the rings. JMHO