Oil sheen- do I chase this or forget about it?

[Slider70]

Sheen or Whatever on Water at Idle

It is either injectors or valves need adjustment

I had the same situation so I had both engines, EH700 serviced with the injectors rebuilt, the valves reset, the timing checked and the heads torqued. Exhaust manifold ceramic coated, all heat exchangers pressure tested including the exhaust manifold bundle. Every five hours or so I run engines to over 80% wot.

End result is exactly the same degree of sheen or whatever it is, on the water at idle. I burn less than a litre of oil between 150 hour oil changes. I also use the boat extensively for over four months of the year.

I have decided to forget about it!

 

[Bonedoc]

If you are going run it at or near WOT, do it under a load.

Yes that was the plan- cruising, not at dock.if thats what you are referring to.

Not going to get crazy about it…. Seems to be less now… but have some great ideas from all.

 

[Slowmo]

I have twin 3208NAs and get a slight sheen as well. Most likely this is fuel since oil consumption isn't a problem. We changed injectors, startup smoke reduced but no change in the sheen. Since you've checked all the likely problem areas (oil coolers etc) it seems like its normal.

 

[Bonedoc]

Thanks Slowmo

 

[timb7734]

Read your owners manual, Yanmar recommends “racing” the engine periodically when warm by gradually bringing the throttle up to maximum while in neutral, and holding there for several minutes. This cleans carbon out of the fuel system.

 

[Bonedoc]

Read your owners manual, Yanmar recommends “racing” the engine periodically when warm by gradually bringing the throttle up to maximum while in neutral, and holding there for several minutes. This cleans carbon out of the fuel system.

More accurately Yanmar recommends racing after a period of “prolonged” idling …. prolonged not being defined. I do just that when appropriate yes.

After changing out fuel cooler, tranny cooler, andI cruising to Ct today at 3400 RPM at 21 knts in a lumpy sea for an hour one way thus far….. no sheen now noted at marina.

So far so good- tx.

 

[rgano]

I read that business about racing my 6LPA-STP before shutdown after extended idle. I don't buy it. Other than trolling, I cannot sea a reason to have "extended idling" after which you can throttle up to where the engine is designed to run. I run the engine at 2800-3100 most of the time underway. I spend a few minutes at idle getting into the boatlift and running the shore water through the raw water cooling system before shutting it down without the racing. Never any sheen at idle and never any dark smoke when first throttling up when getting underway or after and hour or so at low RPM while trolling. If you are one of those people who want to make this high-RPM engine run at trawler speeds all day long, do it and yourself a favor and run it hard at the end of the day for an hour or so at 80% fuel flow which happens to be at 3000 RPM for my boat.

 

[Bonedoc]

I run as you do.

 

[NCheaven]

Smoke reduced

I have a 2005 diesel - Volvo. It was a bit smoky, and two things improved that. I had been running exclusively around hill speed, and my mechanic found black sludge in the exhaust system. His advice to run my engine at higher rpm from time to time, and Steve Zimmerman’s article in PassageMaker in engine life addressing benefits of running engines more often above lower per cent of effort. So, I run at somewhat more rpm and short periods fail close to 80% of total effort.

The other item was a surprise. Reading about diesel oil in oil manufactures’ tech sheets and in tribology research, including commercial marine applications, I decided to switch to synthetic oil. (Yes, synthetic oil manufacturers’ current oil specs wrap former lower grades grades from the 2005 years.). Two years later the Admiral and I notice far less smoke at starting than before.

I’m no expert on engines, but focusing on blowing out the exhaust better than in prior years, and switching to synthetic oil appear to have reduced fuel or oil laden exhaust to a noticeable degree for my great running Volvo TAMD41P-A.

This may or may not help your situation, but it helped me.

 

[Bonedoc]

Yes- running the motor “hot” seems to cure many ills and has been recommended by many here.

I am hesitant to run synthetic oil in the Yanmar as the owners manual does not recommend it- although those recommendations are now dated from 2006. I would have to look into that further.. Tx.

 

[NCheaven]

API diesel oil ratings

Here is a table fromthe American Petroleum Institute on Diesel Oil Ratings

API note: Follow your vehicle manufacturer’s recommendations on oil performance levels.

Listing below is in order of newest to older. API table columns are Category, Status (Current or Obsolete), and Service.

CK-4 Current API Service Category CK-4 describes oils for use in high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm (0.05% by weight). However, the use of these oils with greater than 15 ppm (0.0015% by weight) sulfur fuel may impact exhaust aftertreatment system durability and/or oil drain interval. These oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. API CK-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low- and high-temperature properties, and soot-related viscosity increase.[/U] API CK-4 oils exceed the performance criteria of API CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 and can effectively lubricate engines calling for those API Service Categories. When using CK-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval recommendations.

CJ-4 Current For high-speed four-stroke cycle diesel engines designed to meet 2010 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm (0.05% by weight). However, the use of these oils with greater than 15 ppm (0.0015% by weight) sulfur fuel may impact exhaust aftertreatment system durability and/or drain interval. API CJ-4 oils exceed the performance criteria of API CI-4 with CI-4 PLUS, CI-4, CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories. When using CJ-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval.

CI-4 Current Introduced in 2002. For high-speed, four-stroke engines designed to meet 2004 exhaust emission standards implemented in 2002. CI-4 oils are formulated to sustain engine durability where exhaust gas recirculation (EGR) is used and are intended for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, CG-4, and CH-4 oils. Some CI-4 oils may also qualify for the CI-4 PLUS designation.

CH-4 Current Introduced in 1998. For high-speed, four-stroke engines designed to meet 1998 exhaust emission standards. CH-4 oils are specifically compounded for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, and CG-4 oils.

CG-4 Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 2009.

CF-4 Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 2009.

CF-2 Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 2009. Two-stroke cycle engines may have different lubrication requirements than four-stroke engines, so the manufacturer should be contacted for current lubrication recommendations.

CF Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 2009. Later “C” category oils are usually suitable or preferred for diesel automotive engines for which “CF” oils were specified. Older equipment and/or two-stroke diesel engines, especially those calling for monograde products, may however require “CF” category oil.

CE Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994.

CD-II Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994.

CD Obsolete CAUTION: Not suitable for use in most diesel-powered automotive engines built after 1994.

CC Obsolete CAUTION: Not suitable for use in most diesel-powered engines built after 1990.

CB Obsolete CAUTION: Not suitable for use in most diesel-powered engines built after 1961.

CA Obsolete CAUTION: Not suitable for use in most diesel-powered engines built after 1959.


Note that the API says that the current top rated CK-4 oil can replace CH-4 and CI-4, which were the top ratings when our Yanmar and Volvo engines were built.

Both Exxon Mobil 1 and Shell Rotella 15W40 full synthetic information pages recommend their oils for newer and older diesel engines, and both note certification for Volvo VDS-4 rating - Volvo's newest, highest rating (I have a Volvo engine). When I wrote Volvo America corporate office about synthetic oil, their only reply to me said that they recommend using Volvo products. Exxon Mobil 1 synthetic info sheet noted "fully backward compatable" including older heavy duty diesel engines.

Shell Rotella's 15W40 T6 information sheet has interesting graphs comparing oil performance for wear, oxidation, etc., against partial synthetic and non-synthetic Rotella products - pretty amazing improvement. Both Shell and Exxon synthetic oil information sheets are interesting reading. Also worth reading are articiles from STLE - the Society of Tribology and Lubrication Engineers, which includes at least one article on marine engines. (One was enough for me - way over my head.)

Of course, changing to synthetic oil might not help the oil sheen issue for your Yanmar, but perhaps this information will be useful for TF folks curious about synthetic oil.

 

[Bonedoc]

Soooo……. Went to put boat on mooring this AM… cooler temps 55 degrees….. oil sheen very evident at start uo… less visible at mooring 8 minutes later. I took a few pictures to help quantify.

FYI- opinions on this topic here and elsewhere have been helpful but quite polarized from- “ live with it, it is what it is” to -“ it’s my moral and ethical responsibility to try to fix it.. …. Adjust or change out injectors, lower oil level, oil additives, synthetic oil, test/ change additional coolers, and sending out a sample for testing.

I have about a month of this season to go and I can explore other options on the hard.

 

[rgano]

Given that my 6LPA-STD emits virtually zero sheen/smoke at cold startup now at almost 900 engine hours, if I saw this mess suddenly occurring you can bet I would be talking to my favorite mechanic about valve and injector work as a start, right after I made sure the oil level was correct. That does look like fuel, but I am not betting the farm on it.

 

[Jc180]

Don’t have a Yanmar, have a Perkins. Tough problem to solve. Think you have done due diligence. There may be a few items left to try, but I would add my experience that servicing injectors may not help. Perhaps check the timing on the high pressure fuel injection pump. All of that said, concur with others that at this point certainly diminishing returns in chasing problem.

 

[C lectric]

Don't know your engine so this is general.
Check the valve adjustments. That can affect fuel sheen.
Consider pulling and getting the injectors re/re'd. Ask around for a good shop and for pricing.

Keep this in mind though. Older non electronic control engines often throw a sheen. SOme are much worse than others though.

When cold the combustion chambers do not burn the fuel well so some ends up hitting the water unburned or poorly burned. Don't idle for long periods to
"Warm Up" the engine. First, get all ready for a quick cast off with minimal "Warm Up".

Start and deal with the last lines and go under a light load allowing the engine to warm under some load.

When you are cranking mechanical governors see any speed at less than the idle speed as being under speed so will feed a high rate of fuel to try to speed the engine up. Once the engine fires/starts and the idle speed is achieved the governor will hold the idle speed cutting the fuel feed to do that.

The catch is that unburned fuel has been pushed out of the combustion chambers into the exhaust and then to the water as unburned or mostly unburned fuel.

For this a lot depends upon how quickly your engine fires upon cranking and cold weather will often affect this along with injector or valve adj. problems.

 

[SteveK]

My start up process is to bump the throttles (rpm on start is 1000-1300), start both engines, set idle to 1000 and then walk back to stern to view exhaust to ensure raw water is coming out. I will look close next time but no unusual sheen that would have caused me to take notice.

Does everyone bump throttle or start at idle rpm setting, could my process of higher start rpm reduce the sheen?

 

[rslifkin]

My start up process is to bump the throttles (rpm on start is 1000-1300), start both engines, set idle to 1000 and then walk back to stern to view exhaust to ensure raw water is coming out. I will look close next time but no unusual sheen that would have caused me to take notice.

Does everyone bump throttle or start at idle rpm setting, could my process of higher start rpm reduce the sheen?

I always bring any engine (gas or diesel) up to high idle after start. Carbed gas gets started at high idle, anything else gets bumped up after start, as soon as oil pressure comes up.

 

[SteveK]

I always bring any engine (gas or diesel) up to high idle after start. Carbed gas gets started at high idle, anything else gets bumped up after start, as soon as oil pressure comes up.

And do you have a sheen at high idle.

 

[rslifkin]

And do you have a sheen at high idle.

Any of the smaller diesels I've run haven't. My gassers do have a very slight occasional sheen right at start for a few seconds. Same with the generator. In both cases it's usually when they don't start immediately and may have put a little unburned fuel into the exhaust.

 

[NCheaven]

Idle, etc.

I get ready to launch, reduce lines to one or two before cranking, depending on the wind, waves, crank, idle at 800 (silky smooth, compared to idle below 750), wait about 2 minutes, recover the remaining lines, then exit the fairway at 800 rpm, raising to 1000 2 minutes later, wait for 150 degrees coolant temp, move up to 1200, then gradually power up as temp reaches 175, which is low rpm spec. In fall and spring weather the process is far slower. A Steve Zimmerman article in PassageMaker addressed starting procedures and is worth reading.

No sheen, almost no smoke when cranking (instant, never even once more than 2 seconds, even after not using the boat for a month or two.) Smoke is gone in a minute or so. Smoke was double current amount and duration before switching to synthetic. Quieter, smoother also since switching. Polishing the fuel a few years ago might have created a much cleaner tank. Valvtect fuel, Biobor JF are also standard proceedures. Valvtect also made a favorable difference when I started using that. My mechanic sent off injectors to a professional diesel shop 3 years ago, and that had a favorable impact. (Maybe if I ground up 100 dollar bills and put that in the fuel tank might help, as that is in essence what all of these other things represent!)

On my delivery trip off shore of New Jersey rough seas stirred up residue in the tank, engine was fuel starved, pressure gauge which read zero the prior two days jumped up into the red, so the prior owner on board instructed me to switch the RACOR filters with the flip of the switch on the mounting and we contined the last hour into Cape May, replaced the plugged filter, and I watched the pressure gauge hourly for the remaining days of the trip. That experience was a great lesson for me to do everything possible to create the best possible tank environment and obtain the optimal fuel and additives necessary to manage the fuel quality, starting with certified ValvTect marina refueling. I cut open my used Racor filter a couple of years ago and found it to compare very closely to pictures of a brand new filter medium, and I'll cut open the primary and secondary fuel filters at the end of this season. That's the only way I know that I can be sure of the tank and fuel condition.

 

[Bonedoc]

Thanks all. The big “blurb” at start up has not reoccurred… sheen is mild now.

The big puddle in the first picture above was after an evening where the boat was tied to the dock and took a “saltwater enema”up the tailpipe from an easterly chop pounding the stern for 4 hours. Ran fine after first discharge. Hopefully it did not go up too far.. but I believe I have loop in exhaust.

I will try running up the idle at start up and consider injectors in off season. Thanks again!

 

[Bonedoc]

Accidental oil leak solves oil sheen isdue ongoing for 3 seasons!

A while back I posted concerning a notable oil sheen when docking and startup.

I’ve been scratching my head since and have done the following:
1. New oil cooler
2. New fuel cooler
3. Pulled, serviced, pressure tested after cooler
4. New transmission cooler

No change in sheen

Was about to pull injectors for testing as next step although mechanic doubted that as a source at only 400 hrs and engine running perfectly.

Anyway- oil cooler was leaking underway- loose fitting- dumped 2 qts in bilge.. Got that mopped up and fittings tight. Forgot to add more oil- just a bit on tip of dipstick with oil pressure still fine underway.

Guess what: NO OIL SHEEN IN EXHAUST SINCE KEEPING OIL VERY LOW ON STICK!!!!

The Yanmar 6-LPS dipsticks are known to be inaccurate. Here it is likely the tilt of the motor as well. So even with the bare minimum on dipstick I still have 9-10 quarts in there. More than that in has been frothing the crankshaft etc.

Curious ending to a chronic bothersome issue that may be of interest to other diesel owners.

 

[SteveK]

Said it before the engine finds the level. Adjust dipstick to it.

 

[SIBERNUT]

A couple of drops of Dawn when you start put over the stern.

 

[C lectric]

Glad you figured it out.

A too high oil level will cause that whipping which can also cause alarms of low oil pressure to go off when you come of plane or higher revs abruptly.

After I dropped the oil level by about 2 qts the alarms stopped when I abruptly cut the throttle. My oil consumption also went down.

 

[Delta Riverat]

My dipsticks have a high and a low mark stamped in them (easy to see and 2 inches apart) and I keep the oil level in the middle, 4 gallons.

 

[C lectric]

For anyone reading this trhough if the dipstick marks, high and low, are 2 inches apart someone does not know how to mark a dipstick.
If you are having a sheen as discussed here drop the level to 1/2 way between the two marks and see what happens. It may take a few startups to make a difference but try it.

The lower level will still ensure adequate oil in the sump.

I posted about this before and have now maintained mine 1/2 between the two marks.
Oil consumption is way down compared to before when I attempted to maintain the oil level at or close to the high mark.

So if you do that , 1/2 way between, you will likely find reduced sheen AND reduced oil useage.

 

[OldDan1943]

The dipstick is marked correctly assuming it is mounted on a truck frame, on flat ground.
The next time you change oil, pour in the recommend amount of oil, run the engine to fill the filter. Shut the engine down, let it be, for about 30 mins. Now, check the reading on the dipstick. This will be to new ‘normal’ for you installation. Mark the level with a file, mark down in your maintenance log.

 

[Comodave]

The dipstick is marked correctly assuming it is mounted on a truck frame, on flat ground.
The next time you change oil, pour in the recommend amount of oil, run the engine to fill the filter. Shut the engine down, let it be, for about 30 mins. Now, check the reading on the dipstick. This will be to new ‘normal’ for you installation. Mark the level with a file, mark down in your maintenance log.

Oh yes! That is the way to do it.

 

[OldDan1943]

I should have added, the next time you change oil, after establish you “normal”, add enough oil to be a qt low and mark the dip stick again.
PRESTO!!! Now you have a personalized dipstick for your installation. Write that down in your maintenance log too.
Remember to add the oil it takes to bring back to your normal.