PCM H5 2017 - petrol in motor oil ?

[BennyBoettkjaer]

Motor oil level increase over time - approx. 1L after 12 month. Oil is changed twice a year, and engine runs great without any noise, smoke or smell. We suspect petrol in the engine oil, but where is the leak - any ideas ? Data: PCM H5 year 2017, 1500 hours.

[greggmck]

I noticed this on several of my boats. I narrowed it down to: oil heat expansion and filling the oil after an oil change with exactly 6.5 qts and not always extracting 6.5qts due to limitations of where the drain hose pickup is located.

Keep in mind the oil you are extracting is warm/hot. The new oil is room temperature. This variation plus any difference between what you extract vs. fill can cause the oil volume to increased by a liter or more at the next oil change.

[jmo]

The H5 & H6 direct injection motors are susceptible to fuel dilution of the oil from excessive lugging or cranking when starting. This happened to me on my 2018 H6 motor between a bad battery and a failing throttle base assembly unit. I had the oil tested which confirmed the fuel in the oil.

the next year after the battery and TBA unit were replaced, my oil level stayed constant the whole season.

[BT]

Direct injected engines can also get fuel in the crankcase from the seal on the high pressure fuel pump failing. The fuel pump is driven by the camshaft.

[zcarney]

Hello,

Long time listener, first time caller.

Anybody noticing oil dilution on the ZZ8? Across the last 155 HR's (89 - 244hrs) I've changed the oil four times with a fuel percentage of 6, 8, 5 and 4%. Ironically, wear metals (iron) spiked on the last interval which had the lowest dilution rate (4%) but I'm keeping an eye on causation vs correlation here.

The oil analysis is per Blackstone Labs, but my understanding is they tend to underestimate oil dilution.

PCM and Union Marine have both told me "not to worry and enjoy my paragon" when I've brought this to their attention. Pretty underwhelming support by the dealer.

I should have the analysis back of my previous two oil changes of the summer next week and will make a decision on my next steps from there.

For context, I put ~1500 hours on my 2008 Malibu LSV 23 running the 383 before selling it to a good friend. The oil samples on that thing are still "boring" compared to this ZZ8.

[Scooter G]

Interesting stats zcarney, I'll have to keep an eye on that...
Liked: "Long time listener, first time caller"