Volvo MD2020 Breather Hole

[belizesailor]

Originally Posted by jimbunyard

Guess what, I'm aware of where your air filter attaches. The crankcase ventilation is performed by the passage illustrated in your own picture, shown below. Again, and certainly not so gently, I'm not taking my engine apart to verify something so obvious...

Looking back, I think I misread one of your posts. I get it now. Thanks.

[PedroPV]

The 2003 has an internal passage (round hole on the right front corner under the valve cover) that crosses the intake air duct into the crankcase. Vapours from the crankcase and the valves are sucked into admission and burned in the cylinders. If you have too much oil in the sump or too much blow-by, white smoke will come out of the exhaust.

[Weste874]

Volvo penta md2020 Hello all hoping to get some more insight on this 1st event oil filler cap off engine i assumed it hadnt been tightened 2 weeks later cap off again replaced with new cap and thightened well 2 weeks later major oil leak from block under injection pump a lead plug had blown out i have tapped the hole and inserted a 1/8bsp plug next i removed rocker cover and vent hole is not blocked and gauze is clean any inputs or ideas asto whats going wrong greatly appreciated thanks for looking

[skipperpete]

I’m tempted to plunge in with “crankcase pressure” but if that was the case, you should be seeing some action with the dipstick and tube. How much is blowing out of the oil filler with the cap off?

[Weste874]

Thanks for reply theres no obvious pressure in crankcase but i suspect it builds up over a period of time maybe 1 hr but cant understand why it nots being sucked out into air intake engine has good compression not burning oil and easy to start it doesn't have an air filter fitted would fitting one create more vaccum in the vent line thats my thoughts

[skipperpete]

I have no idea what the lead plug is or why it blew out, could it possibly be that the dipstick tube hole was plugged (with lead?) and the tube moved to another location. I have a MD 2030 and the oil filler screw cap is really hard to undo hot or cold.

[DougR]

There are several pressed in oil passage plugs on the block below the injection pump in the general vicinity that you describe. These plugs close off oil passage cross drillings to the camshaft and main bearings, and have nothing to do with crankcase pressure. It’s good, of course, that you found the leak and plugged it as it could eventually cause serious problems.

Don’t know why your oil fill cap doesn’t want to stay on, as Pete says, they are usually a bear to get unscrewed. Maybe double check the breather hole is open..

[Weste874]

Thanks all for replying ive taken off the rocker cover and breather gallery is not blocked all i can do now is fit an extra loud buzzer for low oil pressure so if i have leak i will get a warning thanks again for help