Lutine mixing oil and deisel - should I limp home?

[magpie patrick]

Lutine's engine, and ST2, has been giving trouble again - persistent overheating after about two hours running. Turned out to be diesel leaking into the oil such that when I changed the oil there was 11 litres in the sump - there should be about 5 1/2! The engine has gone for a four hour run without any distress at all now but the oil level increased again, presumably diesel getting.

We'd actually tried all sorts of things to do with air circulation, exhaust lagging and even wondered if the prop shaft was bent before getting to this...I have a new (to me) ST2 to go in, the engine whisperer (RLWP) has it in his possession and the plan was to get the boat home to Bath and sort it out there. 

First question - Lutine is currently in Banbury, where it is 12 six hour days back to Limpley Stoke - 5 of those days are on the Thames and the Kennet.   Could I limp home by draining the excess off each day and doing a full oil change every three or four days?, If she was past Newbury I'd do this without hesitation, but it's a long way with a lot of river and the Thames isn't even CRT so delays on that are unhelpful.

Second question - if the answer to the above is NO then is it worth getting this fixed or should I hang back and switch engines somewhere on the Oxford? I may well have to wait for the winter and I would like to get her home.

Thanks Folks

[cuthound]

There are two problems with diesel leaking into the lubricating oil.

1. It dilutes the lube oil reducing its lubricity, so you increase engine wear.

2. It can overfill the sump to the point where the engine "runs away", on its lube oil.

This can potentially cause the engine to rev until it self destructs.

12 x 6 hours days = 72 hours.

 

How long did it take to double the oil capacity in the sump?  Only if it was over quite a long time (weeks) would I risk it, and even then I would change the lube oil after 6 days. 

[zenataomm]

Have you looked for the fuel seepage?

Have you drawn a blank regarding any easy(ish) fixes like the pipe unions connecting to the top of the injectors, likewise the top of the injector pumps or the banjo unions in the same area? Nipping them up should help, although be careful it's easy to strip the threads.

Assuming you have already done this, or it doesn't help then I guess it depends on how comfortable you feel about everything cuthound says.

If doing an engine change now is feasible then I would be tempted to do that.  You'd also save money on not having to do oil changes on the way, plus the removed engine would probably be more valuable than by the time you got home.

 

[mross]

It might be as simple as tightening a bolt or union.  Run the engine with the rocker box covers off and see if you can find the leak.  It might splash some lube oil around but not a lot.

[1st ade]

1 hour ago, cuthound said:

How long did it take to double the oil capacity in the sump?  Only if it was over quite a long time (weeks) would I risk it, and even then I would change the lube oil after 6 days. 

The OP said after every 3-4 days if he goes ahead

[alan_fincher]

Although Lister acknowledge that these engines can run OK with a certain percentage of diesel in the sump, (possibly up to 10% allowed, from memory), clearly having twice the volume in the sump you should have represents only 50% of it being lubricating oil.

I think there is a severe danger of it running away with these kinds of volumes present.  If you do try to carry on, then certainly change everything long before you have doubled the volume in future.

(You are also relying on whatever it is that is leaking the diesel in not suddenly doing it at a far faster rate.  If it is a loose union, for example, slowly shaking itself apart, it could well start leaking a whole lot faster at any time).

Edited June 30, 2017 by alan_fincher

[magpie patrick]

Indeed Alan, that's my concern. Against that, the checks suggested are a lot easier than I imagined. 

I now know what the right amount of oil in the dipstick looks like: there is an issue with the dipstick markings I'm relation to this engine 

[man1nvan]

Sort out the leak  i killed an sl2 by not doing so, it ran hot for days then started making clanging noises then went phut    mind you i replaced it with an sr2 which gave a 33% power increase to a whopping 12 hp.

Chances are it is just a loose injector pipe  the post mortem on mine showed that to be the cause of death,  that and negligence on my part.

 

[MtB]

47 minutes ago, magpie patrick said:

Indeed Alan, that's my concern. Against that, the checks suggested are a lot easier than I imagined. 

I now know what the right amount of oil in the dipstick looks like: there is an issue with the dipstick markings I'm relation to this engine 

 

Are you willing to risk wrecking and scrapping the existing SL2 or do you want to keep it?

If the former I'd take a chance. If it is in good nick otherwise and you want to keep it that way, then don't.

Why not change the engine where it is now?

Or fix the leak. I've an idea it is behind the side covers where the injectors reside, not under the rocker covers.

[magpie patrick]

It's not in good nick but it is part-ex with the replacement. 

The problem with replacement where it is is time. This boat should have been on the K&A three years ago by the original plan, sometime last year, and then this Spring. That partly reflects my time availability, I can spare early August for  move, next big window is October, then it would end up being next Spring  (again). If we could do the swap next week I would, but boatyards that can lift and engine get booked up. 

[magpie patrick]

1 hour ago, Mike the Boilerman said:

 

Or fix the leak. I've an idea it is behind the side covers where the injectors reside, not under the rocker covers.

I've suddenly realised that it's probably under the front rocker cover.

This does not necessarily mean I'm competent to fix it though, but I now know where to look

[MtB]

Just now, magpie patrick said:

I've suddenly realised that it's probably under the front rocker cover.

This does not necessarily mean I'm competent to fix it though, but I now know where to look

 

I'm sure fixing the leak is the best course of action. Worth putting in considerable effort I'd have said. 

Is there no mechanic at Tooleys available who knows how to fix this? It's a well known problem AIUI.

Or take a walk up to Sovereign wharf and ask there. Owned and run by a forum member here IIRC.

[magpie patrick]

Don't know about Tooley, but there is at Aynho: I've already had a chat with them. 

I was reluctant to write a blank cheque for what I perceived to be a huge job in the innards. If it's as simple as it now appears it's not an issue. 

[MtB]

Richard has written and posted a thorough article on here about this specific problem. You really REALLY REALLY need to read it.

 

[PaulJ]

I have a copy of a oil dilution in Listers pdf that is quite useful.Cant remember where from but not mine.Not sure what the protocol is about posting it here though? Can I pm it?

Edited June 30, 2017 by PaulJ
Snap-posted at same time as MtB

[David Mack]

There's another diesel-in-the-oil thread on here where another possible cause suggested  is leakage past the diaphragm on a mechanical fuel lift pump.  Again fairly easy to check, (and not applicable if you have an electric lift pump or gravity feed).

[Dav and Pen]

Had this problem with HB. It was the leak off pipe and there had been a mod at some stage that hadn't been fitted. Everybody knew of the potential problem. Get the covers off and have a look.

[Arthur Marshall]

Had this on an sr2, was a crack in the leakoff pipe invisible to the naked eye. Listers can apparently cope with up to 60% dilution - mine went up an inch on the stick in a week. I just drained it down to the min level and refilled it a time or two and did a complete change every 3 weeks. If it overheated, the engine just stopped. 

[hounddog]

Fix it. it will be something simple. If it's the leak off side you can bodge something to take the diesel away. if it's the high pressure side it will be immediately obvious where it's coming from. 

Certainly take the covers off and the side case in front of the pump and have a look with it running. 

Changing the oil every few days will cost you a fortune. 

[magpie patrick]

28 minutes ago, hounddog said:

 

Changing the oil every few days will cost you a fortune. 

About £60, which to get her home, where a mooring is being paid for, and I can do things at leisure rather than against the clock, is not bad value IF IT WORKS. A week or two's mooring on the Oxford Canal would cost the same. 

However spending about £60 quid to completely knacker the engine and end up stranded at Abingdon would be poor value indeed!

30 minutes ago, hounddog said:

Fix it. it will be something simple. If it's the leak off side you can bodge something to take the diesel away. if it's the high pressure side it will be immediately obvious where it's coming from. 

Certainly take the covers off and the side case in front of the pump and have a look with it running. 

 That's what I plan to do

[MtB]

My gut feeling is this can't be that difficult to fix. Or at least fix enough to get the boat home.

Get those covers off and have a look. I think the leak will be bl**dy obvious. Post up some photos and someone will know exactly how to fix it.

[X Alan W]

14 hours ago, magpie patrick said:

I've suddenly realised that it's probably under the front rocker cover.

This does not necessarily mean I'm competent to fix it though, but I now know where to look

Most probably a cracked Injector leak off pipe a bit of Achilles heel on that type of Lister  usually where the various bits are silver soldered together If it is you should be able to see the leak if you run it with one rocker cover removed at a time if top end  is good It requires the side doors under the air ducking removing to check the fuel injection pumps supply & injector pipes Is it not possible your engine guy to check & effect a repair /fix were the boat is at present. you then could boat hopefully trouble free to the spot to change your motor ( IF the diesel leak was fixed does it need replacing)

[magpie patrick]

1 minute ago, X Alan W said:

 ( IF the diesel leak was fixed does it need replacing)

Oh boy, it needs replacing - there are so many bodges on this engine, which wasn't installed well in the first place. Even if I wasn't replacing it i'd lift out out and start  again on the installation. 

Last year's overheating was caused by the engine having been badly rebuilt, with a plate relating to the air flow system having been fitted upside down...

[Bod]

If you do decide to "risk it" keep a CO2 fire extinguisher handy. 

This is possiblely the only way to stop a runaway engine safely. 

Empty the extinguisher into the air intake to starve the engine of oxygen.

 

Bod 

[MtB]

Good advice. Think about and prepare a strategy to stop it should it run away, BEFORE it actually happens. 

A method of fully blocking the air intake might also work.