VP D3-200 expelling its oil

[PicoGoss]

I have a RT-28 inboard with the Volvo Penta D3-200. Three times in the three years I’ve owned her she has expelled most of her oil causing a low oil pressure alarm. Each time we thought it was caused by not firmly seating the dipstick, although this latest time I did not find the cap loose and we hade traveled over 160 miles since the last oil level check. In between events I have cruised sever thousand miles. Several questions come to mind:

Has anyone else had this issue?

Is there any better explanation for seemingly random loss of significant engine oil?

Has anyone else ever ever had a similar issue on any engine? I’ve had autos for over fifty years and this is my fifth inboard diesel cruising boat and have never had an issues with dipsticks.

 

[Capt’nKarl]

I’m not familiar with this specific engine but do you see oil on the engine or around the oil dipstick ? Is there oil in the bilge? Is the engine exhaust normal?

 

[pleeson]

Is your oil breather filter clogged?

 

[BB marine]

You did not specify where the oil s expelling from. I'm assuming it is expelling from the top stick. If this is the case a couple of things come to mind.
(1) The dip stick must be firmly clipped in place after checking the oil. You should feel a snap or click when the dip stick is fully inserted.
(2) There is an o-ring seal at the top of the dip stick to seal the blow-by pressure from blowing oil past the dip stick. Is this O-ring in good condition or is it there? Remove the dip stick and inspect the o-ring. If the ring is damaged it will allow oil to expel.
(3) When you change your oil in a D3 the oil level should be checked. When you check the oil level you must make sure the boat is level. I actually installed a small level bubble to confirm the boat is not listing port or starboard. A list to starboard will show low oil level a list to port will show a high oil level. I have found that filling the oil to the full level mark could cause the oil to expel. I have found that the Turbo will be (Compressor side) wet with oil because the crankcase ventilation picks up more oil and causes more oil vapors to be expelled. The oil level should be between the full and add marks when checked or filled after an oil change to be the proper level and reduce the chance of oil expelling out of the dip stick and crank case ventilation system.
(4) The ventilation filter needs to be replaced every 200hrs or once a season. This filter is around $140.00 easy to change but important to change. If it is fouled enough it will cause increased crankcase pressure and possibly cause the oil to be expelled.

Checks- dip stick installed properly, O-ring in good condition, oil level correct, ventilation filter changed at recommended intervals.

 

[PicoGoss]

Thanks Brian. It’s good to know our suspicions re the dip stick are well founded if hard to believe. The good news is that I have a new crankcase ventilation filter on board. Maybe too bad I hadn’t replaced it in my engines 400 hour life. Tomorrow morning’s first priority.