2GM20 Blows Out Oil

[Wotname]

FWIW, I had a brand new 2GM20 (with no obvious crankcase pressure) and if you run it without the dipstick fitted, it sprays oil everywhere from the dipstick hole - don't ask me how I know

I still think the OP's dipstick is just too loose for some reason and it might not take much pressure to pop it out.

[Compass790]

Originally Posted by Wotname

FWIW, I had a brand new 2GM20 (with no obvious crankcase pressure) and if you run it without the dipstick fitted, it sprays oil everywhere from the dipstick hole - don't ask me how I know

I still think the OP's dipstick is just too loose for some reason and it might not take much pressure to pop it out.

Yea well maybe the OP's easiest fix is just to put a removable clip on the dipstick tube to prevent the dipstick blowing out.

If the engine is running well & oil pressure is ok I cannot see any problem with that.

Think that jimbunyards analysis in post #25 sums the rest up well.

[Sonosailor]

"Can you elaborate more on what happens with the oil pressure senders?
Are these just alarms or to oil pressure gauge?"

These are just senders: I think, just a baffled set of contacts that open as the oil pressure increases. Sadly, I changed two things at once: I cleaned the engine with the solvent (50/50 in the oil), AND purchased the new sender directly from Yanmar, rather than off a shelf in a chandlery. I have had no more sender problems. I replaced the sender for a few hours with a contraption with a proper pressure guage, and the oil pressure, at all engine speeds and loadings, remained within reasonable parameters, albeit at a slightly high end of the range.

[Sonosailor]

I reviewed my notes, and realized that the solvent was about 50%, mixed with new 15/40 oil, for the cleanup. I have since done this trick again this year, but using a special product off the shelf, as suggested above. This was done with Covid - 19 closures breathing down our necks, as we ran the boat quickly back to Grenada to catch the last normal flight out to Toronto. We'll see how the next season goes - and when the next season goes, sadly.

[Sonosailor]

So, what am I trying now? I found a 6 ounce fishing weight, and have put it on the stick. It should provide a little more protection if it is just a minor pressure causing the problem.

[wguinon]

Glazed cylinder walls. Hone them

Do you run much with a lite load? e.g. battery charging?