Slight oil sheen

[Knot Safety]

Team,

Question for you wise ones. I have a slight sheen on the water coming from my 3jh5e

Background for you

It sounds and runs fine. I did a complete service the other day - oil, filters and impeller. When doing the impeller I had one vane missing and found it in the heat exchanger. While the exchanger end cap was open I had some coolant weeping out around the seal. Not having a new seal handy, I greased the old one up and put back in.

Bled the engine and fired up. Not promptly but within 6 seconds or so.

Noticed a very slight sheen on the water from the exhaust. Not continuous, just bubbles and drips. Thought it was possible excess coolant or glycerin from new impeller install.

Motored with engine for two hours intending to flush it out. After motoring, sheen is still there, and what were drips and drops is now near continuous. Not lots, but enough to say heck. Coolant and oil levels are exactly where they were on departure.

Figured it was the oring for the exchanger and coolant was making its way into the exhaust. Was about to pull the end cap and had a brain wave to check if the coolant made a sheen on the water. Put a few drops in the water. No sheen. That should rule that one out.

There is no smoke, black or white. I can’t say this wasn’t happening before, but can say that I had not noticed it before the service - and I’m check water flow out the exhaust ever single time I start up.

The only thing different is the oil level is slightly high. I added a touch more. It is right at the full dot on the dipstick - but not over.

So, what are your thoughts - fouled injector? How do I confirm this prior to ripping apart? Perhaps Slight oil passing that will get better if oil level drops? Any other suggestions for things to test and try? Part of me says to leave it, run it hard for four hours or so. If still no coolant or oil level change, then it has to be an injector.

The other engine that was serviced at the same time - no issues

I welcome your feedback

[MV Wanderlust]

Based on your description, it sounds like unburned diesel fuel to me. Injector service and valve adjustment might just take care of it.

[Lepke]

Light sheen is usually a worn injector tip. Otherwise rings, valve stem seal, and oil heat exchanger leak. A compression test will show the condition of the cylinders. Leak down test is better.

Start with the cheapest first. Buy injector tips or have the injectors rebuilt. If the engine has an oil/water heat exchanger, have it pressure tested. If someone used too much ether on the engine, you could have a cracked ring.

[Knot Safety]

Thanks folks. Appreciate the insight. Looks like an injector job in my future. Anyone have a guidance for injector removal of a Yanmar 3jh5e? YouTube videos do not seem to have the same style of injectors as on mine. They appear to be held in place by a single bolt

[a64pilot]

Usually injectors come out without much difficultly. But it’s not a bad idea to spray penetrating oil around the base of them the day before removal.
I’m not familiar with your engine

[Dsanduril]

If you are planning to use a shop for the injectors see if they will loan you a slide puller. The shop I use will. I get the injectors all ready to pull (lines removed, bolts pulled, etc.) then run over to the shop, borrow the puller, take it back half an hour later with the injectors. Injectors can be easy or hard depending on the engine, how long they've been in, and many other factors, but the right tool makes things so much easier. Screw it onto the injector head, slide the hammer up, move on to the next one.