Cruisers Forum

Thread Tools Search this Thread Rate Thread Display Modes
Old 04-06-2020, 05:03   #1

Join Date: Jul 2019
Posts: 153
Slight oil sheen


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 canít say this wasnít happening before, but can say that I had not noticed it before the service - and Iím 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
Knot Safety is offline   Reply With Quote
Old 04-06-2020, 05:12   #2
Registered User
MV Wanderlust's Avatar

Join Date: May 2016
Location: Palmetto, FL
Boat: "Wanderlust" -- 1999 Jefferson Rivanna 52'
Posts: 875
Images: 28
Re: Slight oil sheen

Based on your description, it sounds like unburned diesel fuel to me. Injector service and valve adjustment might just take care of it.
John and Deb Easley
John - USCG 50 ton Master
1999 Jefferson Rivanna 52' CPMY
MV Wanderlust is offline   Reply With Quote
Old 04-06-2020, 12:17   #3
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 3,089
Re: Slight oil sheen

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.
Lepke is offline   Reply With Quote
Old 04-06-2020, 12:26   #4

Join Date: Jul 2019
Posts: 153
Re: Slight oil sheen

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
Knot Safety is offline   Reply With Quote
Old 04-06-2020, 12:46   #5
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,473
Re: Slight oil sheen

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
a64pilot is offline   Reply With Quote
Old 04-06-2020, 12:52   #6
Registered User
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 4,006
Re: Slight oil sheen

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.
Dsanduril is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sudden oil sheen from Yanmar? OrangeCrush Engines and Propulsion Systems 18 13-07-2017 15:22
Very slight oil over fill...problem? svjobeth Engines and Propulsion Systems 13 11-01-2009 13:42
The mast has lost it's sheen Hugho Construction, Maintenance & Refit 3 09-04-2008 16:49
White smoke and oily sheen on water from new rebuilt Yanmar 3JH2E Woody on "Hannah" Engines and Propulsion Systems 25 16-04-2007 19:07

Advertise Here

All times are GMT -7. The time now is 05:02.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.