Diesel in lube oil - the saga continues

[Birvidik_Bob]

Hello again chums. And so it goes on. One question answered and another, equally fascinating, takes its place.

Looks like it was definitely diesel in the lube oil which caused the progressive loss of oil pressure and excessive white smoke. The cause is still a bit of a mystery. It wasn’t the spill rail (external to the rocker box), nor the lift pump. Injector pump looks unlikely as well although we haven’t looked closely at it yet.

All four injectors were severely carboned up and the needle valves were sticking on 2 and seized on the other two. These had only done 11 engine hours since the nozzles had been replaced. Oil was changed and all filters, fuel & oil, replaced at the same time. The mechanic in Lefkas says that the sticking valves could have caused excessive delivery of unatomised fuel which would account for the white smoke and could have leaked past the piston rings into the lube oil. Seems feasible to me.

He also says that in his experience sticking/seizing needle valves are commonly caused by water in the fuel. We did pick up some seriously iffy diesel in Gouvia (all 800 litres of it). This (posts passim) had 5L of water and a lot of bug which we drew off from the sump. Further drawing showed traces of bug and seriously cloudy fuel that did not separate on standing.

We treated this with Grotamar 71, shock treatment dose. It doesn’t seem to have solved the cloudy fuel problem, though it’s probably given the bug a bit of a headache.

This lends some credence to the water in fuel theory, but there is no sign of water in the bowl of the CAV separator/filter, and the fuel in the bowl is not cloudy, having passed through the filter element. So it doesn’t seem as if water’s getting through to the injectors.

So – any theories as to the culprit? I’m tempted to get all the fuel drawn off and filtered and then clean the tanks before refilling, but I’m still not convinced as to the root cause of the diesel in oil problem and don’t want a repeat halfway across the Aegean.

 

[oceanpilgrim]

hi
when i had a tank of parafin/diesel mix sold to me when you left it to stand for a while the two seperated in to two different bands ,the parafin is i am told has more water in it ,just a thought

 

[Swagman]

Is there not someone local with an in line set of filters to recycle the fuel through? Take from bottom of tank and pass back via filler for a 12 hour run will usually remove most unwanted parts.
Good luck
JOHN

 

[Marsupial]

The culprit is probably a set of dodgy injectors they should last years. The wet fuel a contributory factor. At the risk of starting a war I would suggest fuel set or something like it to rid your diesel of water and kill of the dreaded bug. It works by combining the water with the diesel and rendering it harmless, biocide wont do that.

 

[Heckler]

Glad to see my thoughts were on the right track, it was duff injectors, 40 years of repairing and rebuilding diesels helps!! 11 hours running should not have "severely" carboned up the inectors, they should still be clean with just a bit of soft carbon on them, easily removed with a rub of the thumb. I would be looking at my mechanic for an explanation!!
If there was water in the fuel it would be separating out in the pre filter bowl. Again I think that some one has been a naughty mechanic and is now wriggling!! Having said that if the fuel looks cloudy, give it a good straining a la refuler advice
Stu

 

[Chris_Robb]

Bob -problems problems....

My Victory had bolt downs lids on top of each tank. Are you the same? If so, take the lids off and suck out 10 or so ltrs from the lowest point in the tank at the front end. I used to use a small electric bilge pump and decanted into lemonade bottles so that you could see how the crap was clearing.

When I got the boat it was suffering seriously from water in the diesel. Do not even think about draining the water off via the taps at the front end of the tanks, as they are well above the bottom of the tank.

I would also suggest in the long term putting a decent filter set up such as the Racor 500 which makes changing filters a 1 minute job, without a mess. I hate the CAV filters!!!

Good luck

 

[omega2]

The injecter pipes go into the side of the head? and are locked with a large thin flat nut? that keeps the oil seal in place? but have you tightened up the pipe to injector joint, if you have not then diesel will leak into rocker cover and mix with the oil.

 

[Heckler]

I think we have found out that the prob was bad injector nozzles, they would have been injecting near enough neat diesel in to the cylinders, washing past the piston and diluting the oil. That would explain the white smoke, (not combusting properly) the lack of power and the final stoping of the engine.
Stu

 

[Bilgediver]

Is there not someone local with an in line set of filters to recycle the fuel through
************************************************

Unfortunately it is not possible to filter out the diesel oil as it will have mixed with the lube oil. Just have to bite the bullet and ditch it.

 

[Malish]

I've had a few bad experiences with injectors serviced by so-called professionals in the past. Most of the issues, such as cracked faces of the injector nozzle (which then p*sses out diesel) relate to the use of cheaper pattern parts. Found a good chap now who only uses original manufacturers parts and takes real pride in his work: Rochester City Diesel located in the Medway Towns (Kent); sadly, given the distance, this recommendation is probably not much use to the OP!

 

[Dave_Seager]

I think that you are mixing up two different issues here. He apparently has water in his fuel tank and diesel in his oil sump.

He should be able to filter the fuel in his tank to remove the water but will need to change his engine oil if it is contaminated with diesel.

 

[ADLS]

How much contaminated diesel do you have left in the tank??

If it's just 10 galls or so I'd ditch it, flush the tank and refill. If you have more you TRY filtering, buy an electric fuel pump, a large truck type filter base and some elements and filter your tank via the sump plug.

I had diesel bug and even though I did all the above plus I was able the get into the centre section of the tank via the inspection hatch and give that section a good clean I was not able to get passed the baffel plates to the end sections and had to make do with just flushing out the goo.
New primary and engine filters fitted, the best of the comtaminated fuel returned to the tank after being course filter and then put through a truck filter 3 more times.
About 50 galls was filtered and 100 gall new fuel added, sialed from London to Dunkirk via Dover and on the return crossing to Ramsgate lost both engines due to blocked filters. Being fed up with the bug problem I've fitted a new smaller tank and filter/pipework system when I re-engined, now I keep the tank topped up full all the time from 2 Jerry cans so condensation is lessened. But of course this will not be worth much if the bought fuel is contaminated, if I suspected contaminated fuel I would buy it by the Jerry can and filter it before putting it into the tanks.

As for the injector problem I don't have a clue, as for me I'd clean the fuel first and fit new injectors.

 

[TQA]

I think it unlikely that your injectors are the reason for diluted engine oil. If the injectors were leaking into the combustion chambers or the spray pattern was set incorrectly the symptoms would be lots of black smoke. If it was bad enough to dilute the oil the smoke would be amazing.

Keep looking!

 

[Heckler]

Wrong!

 

[Marsupial]

Many years ago a diesel tank on a boat I crewed was topped up with water. The problem was identified straight away and the tank was drained, removed steam cleaned refitted dosed with biocide and refilled with new fuel.

BUT, Every month or so the bug took hold and the process had to be repeated.

The tank was drained, removed, steam cleaned refitted and dosed and refilled with new fuel several times but to no avail, without fail the bug returned. We were almost able to change filters in our sleep. Life was getting silly and this saga unfolded over a period of several years!!! It was really bad - every time we went sailing we had to change filters to leave the marina and hoist the sails, the tanks were out several times a year and still the bug persisted. We became expert at sailing onto the pontoon because the engine wouldnt start - again.

Then we found fuel set, problem solved. It did what it says on the packet. The boat was sold 10 years later in 2002 and the bug problem did not recur in that time. The fuel was always bright and clear in the class bowl, not like a cloudy claret as before. The engine a volvo 2002 fired up every time and ran smoothly.

I have no connection with this product. Since then the early 1990's I have used it in petrol engines, central heating boilers and trucks with wet fuel. It has worked every time.

Its non invasive surgey and well worth a try.

As others have said I have had more than my fair share of problems with engines when the injectors have been "re-calibrated" I am sure they just exchange them for a another set of same type after polishing the nozzles with a wire brush so you get some one elses problems.

Bit the bullet and buy a set of factory approved injectors they will make a huge difference.