Lister air cooled 3 cylinder diesel leaking diesel into oil

[newbrightonboat]

Bit of advice needed .. our Lister engine has started losing diesel into the oil. Sump level rising about 1 mm every day of running.

Oil/diesel drained and replaced and shut down for winter.

Will check exact model number when visiting this week!

Could anyone please advise possible/probable causes and remedies. 

The engine runs well (otherwise). 

Thank You

Neil

 

[Tony Brooks]

Most of the fuel pipes are inside the engine cases so leak from either end of the injector pipe unions, leak from the bleed screw on the injector pump, leak from leak off pipe unions on the injector. Broken fuel feed pipe or leak off/bleed inside the engine cases. Occasionally a screw in the back of the injector pumps might leak or the pump itself may leak from the bottom but those are much rarer. The lift  pump may have slit it diaphragm so put your thumb over the inlet and out let in turn, spin the engine for a few seconds and see how long it will hold pressure. If less than about 30 seconds the diaphragm may have split but there is often a tell tail under the pump that lets the fuel drip out.

[BEngo]

Listers making oil is a common but a potentially dangerous situation.  With the engine hot it may start to burn it's own oil and run away at full speed.  

You need to find and fix the leak which is causing the rising oil level before doing much, if any,  boating.

 

Take the side door off, where the injection pumps are.  The leak is usually in there, often  from the feed pipe to the pumps, occasionally from  the pumps themselves,  rarely from the pipe to the injectors.

 

You can run the engine with the door off to check for leaks.  if no leaks in the pump chamber, check the lift pump diaphragm.

 

Renew the oil once you have found and cured the leak.

 

N

[Tony Brooks]

Also worth taking the rocker covers ff to look at all the injector unions.

[Arthur Marshall]

Mine has always done it from the leakoff pipes. I suspect they need replacing for the third time. It seems a weak spot in the system.

Listers can run happily with a huge amount of oil contamination - I used to wait till it was an inch up the stick, empty half out and replace with new oil. Did that twice then a full change. If it gets too thin, the engine will overheat. Mine (SR2) just used to stop rather than do the runaway thing.

Obviously better to fix the problem, but it too me six years to find someone to do it, engineers who understand Listers are thin on the ground. The bloke who rebuilt the engine refused to believe it was happening.

[Tony Brooks]

6 minutes ago, Arthur Marshall said:

Mine has always done it from the leakoff pipes. I suspect they need replacing for the third time. It seems a weak spot in the system.

Listers can run happily with a huge amount of oil contamination - I used to wait till it was an inch up the stick, empty half out and replace with new oil. Did that twice then a full change. If it gets too thin, the engine will overheat. Mine (SR2) just used to stop rather than do the runaway thing.

Obviously better to fix the problem, but it too me six years to find someone to do it, engineers who understand Listers are thin on the ground. The bloke who rebuilt the engine refused to believe it was happening.

 

They are very thin and copper so I think they work harden by vibration and then snap. The ones with the self bleed pipes up from the pumps seem to be worse for it.

[newbrightonboat]

Thanks for the speedy reply folks. Yes I am well aware of run away diesel engines. A few horror tales abound!

You have given me plenty of excellent tips.

Many thanks

Neil

[Tracy D'arth]

I believe that annealing the copper pipes is a necessary service procedure to stop them hardening and cracking.

 

Don't ask RCR, they know nothing about Listers.

Edited February 28, 2021 by Tracy D'arth

[Phoenix_V]

2 hours ago, Arthur Marshall said:

Mine has always done it from the leakoff pipes. I suspect they need replacing for the third time. It seems a weak spot in the system.

Listers can run happily with a huge amount of oil contamination - I used to wait till it was an inch up the stick, empty half out and replace with new oil. Did that twice then a full change. If it gets too thin, the engine will overheat. Mine (SR2) just used to stop rather than do the runaway thing.

Obviously better to fix the problem, but it too me six years to find someone to do it, engineers who understand Listers are thin on the ground. The bloke who rebuilt the engine refused to believe it was happening.

We had this common problem, it was a shared boat so little got done for a long time, when it was finally fixed the engineer remarked that the engine insides were the cleanest he had ever worked upon

[Arthur Marshall]

2 hours ago, Tony Brooks said:

 

They are very thin and copper so I think they work harden by vibration and then snap. The ones with the self bleed pipes up from the pumps seem to be worse for it.

That explains it. When the last guy came to fix it, the one he was putting on fell to bits before he got it on.

[Tony Brooks]

1 hour ago, Arthur Marshall said:

That explains it. When the last guy came to fix it, the one he was putting on fell to bits before he got it on.

That is why a winter job on the hire fleet was to anneal the leak off pipes.