Change in Oil Level

[BobFino]

Here is an odd one. As always I do the engine maintenance that I am capable of which includes oil changes. Once I did the oil change I ran the motors to be sure the oil filled the filters etc. Checked the dip stick and it was right at the full mark. I ran the boat for a quick scum run as I like to call it and all ran well. Over the weekend I checked the oil and the port engine was showing slightly above the full mark. I thought that was odd and called my "MAN" man and he explained there is a check valve that holds the oil in the filters and its possible the oil is seeping past the check valve and going back in the oil pan. He then suggested I start the engine, let it run for a few minutes then shut it down and after about five minutes check the oil level again. I did, and the oil was right at the full mark confirming what he thought and and not to worry about it. Not always accepting the first answer I get, it was also suggested that I drain a small amount so when I check the oil it will not show over full but still being in the safe area. Just thought I would check to see if anybody else experienced this and what they did?

 

[carterchapman]

Thanks for the info Bob - but I have not experienced that with my CRM 900's

 

[BobFino]

Thank you for responding. It seems I am alone with this situation. I checked with a couple other service centers and I get mixed response on what to do. It seems the general consensus is to leave it alone, there is no damage being done. However, sometimes I have a problem accepting that.

 

[NotHerDecision]

Bob

My initial though is something could be leaking into the oil. Water or coolant. Personally I would take an oil sample and send it in. For 35 bucks with black stone it gives me piece of mind.

 

[Thornton69]

Unless marked otherwise, the level on a dipstick is for an engine that has been at rest and is cold. It is normal for a hot engine to read high and even low. There are bulletins out for some diesels (6.7 Powerstroke that I am aware of) that request 20 mins at rest if checking it hot before an accurate reading can be determined.

 

[BobFino]

Thanks for the info, I did do the oil sample and I am happy to say all is good there. I did speak with another MAN tech and he agreed with my "MAN" Man that there is a check valve in there and it would not be worth chasing it down, there is no harm being done. I just like things to be right, but I might need to live with this one or at least for now.

 

[carterchapman]

Hi Bob. We recommissioned this weekend and my port engine was a half inch overfull and my stbd was in between the marks where they both were last fall. After start and run, the port is back in between. So i must have one of your bad check valves...I've got MAN coming this weekend to reprogram my new MMDS board, and I'll "ax" him...

 

[BobFino]

Well I am sorry you are having the same issue but I will be really curious what you man has to say. Thanks for getting back to me.

 

[BobFino]

Hi Carter, By any chance did you have a minute to ask your "MAN" man about the oil level changing?

 

[Henry Boyd]

Unless marked otherwise, the level on a dipstick is for an engine that has been at rest and is cold. It is normal for a hot engine to read high and even low. There are bulletins out for some diesels (6.7 Powerstroke that I am aware of) that request 20 mins at rest if checking it hot before an accurate reading can be determined.

Just saw this thread. Our Volvos have a similar recommendation in that they basically say don’t check the oil hot, only after engine is cold.

 

[bmac]

Just saw this thread. Our Volvos have a similar recommendation in that they basically say don’t check the oil hot, only after engine is cold.

That is not the direction that MAN gives. Engine off after achieving operating temperature, check oil level after 20 minutes. I assure you, they are not cold in 20 minutes.

 

[Henry Boyd]

That is not the direction that MAN gives. Engine off after achieving operating temperature, check oil level after 20 minutes. I assure you, they are not cold in 20 minutes.

The similarity is that oil checks are to be done under specific conditions, I.e. specific temperature and having been static long enough for oil to have stopped draining. The intent being consistent results. The implication of that is oil level results must vary widely during the operational cycle.

 

[ttmott]

Interesting on where you maintain the oil level. I maintain oil level on the low end of the dipstick marks (Cummins) to minimize aeration from the rotating components. I also did that on the other boat (Cats).
I wonder what Mr. Webster's take on all of this is?

 

[my3sons]

The similarity is that oil checks are to be done under specific conditions, I.e. specific temperature and having been static long enough for oil to have stopped draining. The intent being consistent results. The implication of that is oil level results must vary widely during the operational cycle.

I agree. Like having to check transmission oil a certain amount off time after shutdown to insure that oil is drained back from a cooler or not yet drained back from a cooler, depending on manufacturer.
My engines will show a slightly higher level the next day after an oil change or check after shutdown because of the block draining completely down. Like pumping oil out of the motor with the reverso until it's sucking air, then taking the time to fill the new oil filter and install it, then going back to the reverso and getting a little more oil out because small amounts are still draining to the bottom of the pan.
Like some have said, I don’t let the small fluctuations bother me, I keep the oil level such that no matter when I check it, it is at or sightless above the low mark.

 

[Brett H]

I haven't noticed the fluctuation of oil level described. I hate the 20 minute wait before checking the oil. Hell, 2 minutes and I'm distracted off doing something else. Next time I think about it over 2 hours have past. UGH. Good thing Suri can set a timer or I would never get it right.

 

[carterchapman]

Hi Carter, By any chance did you have a minute to ask your "MAN" man about the oil level changing?

Bob - he confirmed the check valve is there and said it is not uncommon for them to leak down over time and not to worry about it... I'm stopping by the shop next week and I will ask my "boss MAN man" if its something that should be changed/replaced. It is there to keep the oil filters full for start...

 

[BobFino]

Thank you Carter, I appreciate the follow up and the comfort of knowing that your guy agrees with my guy on nothing to worry about. If you have a chance, let me know what your "boss MAN man" has to say. Thanks again, Bob

 

[carterchapman]

Thank you Carter, I appreciate the follow up and the comfort of knowing that your guy agrees with my guy on nothing to worry about. If you have a chance, let me know what your "boss MAN man" has to say. Thanks again, Bob

I will Bob. I'll see him Friday...

 

[All's Well]

Great thread - I had the same issue this week with my MAN V8-900's
I was just about to pump out about a gallon from stbd engine when Josh "Not Her Decision" mentioned this thread to me. I ran the engines up to temp and then checked oil level and it was spot on, over correction averted!!

 

[carterchapman]

OK - here's the word from my "MAN man". He says that it is the check valve and it is not an "a la cart' part - you have to replace the entire housing, and his words were "and you don't want to know what that costs"...

He said its not a problem, the 5W40 oil that we use will quickly get to the bearings just like a start after the oil has been changed and the filters would be completely empty then...

When we get to the boat next weekend, I'll be interested to see if my port engine has "leaked down" in a two week period.

I think BMAC posted above that oil levels should be checked 20 mins after shutdown. I've always checked them weekly prior to start, and this was the first season that Reward went 7 months without a start...I'll start trying to be more disciplined (like Bryan) and do mine according to the book...