Fuel seeping in to crankcase

[Stevie Blueboat]

Need ideas, please! I have a Westerbeke 4108 and have been getting fuel seeping into oil pan. I changed the lift pump, since that seems to the the only "hole" where a leaky diaphragm would let fuel into the crankcase. After about 80-100 hrs, I have been draining about a quart more oil than what I put in last oil change. I will be popping the injectors this coming week, thinking that they may be getting funky and dripping fuel when the engine is off, which would allow the fuel to seep through the rings to the crankcase. My question to anybody.... am I on the right track? Anybody seen this before? Everybody else I know is stumped. She seems to run fine otherwise.

[Alan Wheeler]

I'm not familiar with a Westerbeck. Although 4108 is the same No as a Perkins. Is it a Perkins by anychance?
Fuel can get into oil in a couple of situations. Lift pump as you have noted. Injector pump drive seals can also be a possible but rare. Injectors themselves are quite possible. Leaky seats allowing the injector to drain, a poor spray pattern allowing the fuel to pour instead of spray. this allows small amounts to get onto the cylinder walls and swallowed by the piston gap and therefore missing being ignited. worn rings and glazed bores are a major possibility. Of course, all this depends on many other factors you have not noted. Engine hrs, exhaust smoke quantity and it's colour. Does it start cold OK. Does it start hot OK. Have you noticed a change in it's start habits. How long since injectors were overhauled and so on.

[Stevie Blueboat]

Thanks for the input, Wheels....

Yes... the 4108 is a Perkins. Westerbeke and Perkins are pretty much clones of one another.

I am in tropical waters, so I don't worry about a thermostat, so when she starts up, I get a little white smoke until the engine warms up. No trouble at all starting when warm. There no glow plugs, only a heater near the air intake throat, so starting in 50 deg cold weather takes a couple hits with the key.

I think your idea about the injector squirting instead of a mist may make sense. I'll be popping the injectors this coming weak to have them bench tested.

I really HATE dealing with this mystery, however.

/Steve

[delmarrey]

A couple more possibilities, a cracked head or head gasket going bad. Have you checked for blow-by while the motor is running?

And how long is it before the oil blackens?

We need more deatails like, Alan says.

[Stevie Blueboat]

No black smoke, idles fine. Oil blackens after about 2 weeks, but it is not thick, black and ugly. I run the engine daily. I live on the hook, so I run the engine to help the solar panels along after a long night of TV. Aside from this issue, she seems to run the same after my rebuild 5 yrs ago. I'm not sure of any evidence of a cracked head. I am not getting steam in the exhaust.... I don't think.
/Steve

[delmarrey]

One thing I can say is it's not good on diesels to just sit and run unless they are under load. The cylinders become polished and they loose compression in which the rings are not seating properly.

You would be better off to buy a cheap gas generator and run that to charge batteries.

You may want to do a compression check. If the injectors are seeping and have polished cylinders. That COULD be your source.

I'd say do the compression check and then have the injectors tested. That will at least eliminate those possibilities............................_/)

[Alan Wheeler]

A cracked head won't let fule into the crankcase. It could allow water in, or oil into the water.
Injectors should be treated like spark plugs. They need servicing. Aprox every 1000hrs they need adjusting. I will assume they were rebuilt when the engine was. although it is quite possible if they were in reasonable condition, that they just got a clean and recalibration. They may now need reseating or even new nozzles.

When using an engine daily to charge batteries, there are two important things to do. Firstly, get the engine/gearbox engaged ASAP. Start the engine, let the oil pressure come up and engage the box. Reverse is fine and simply Allow the boat to pull on the mooring. The other issue is to not allow the engine to idle dead slow. Lift the RPM slightly to say 1000RPM if you can. This stops "injector shock" from rattling the drive train and destroying it. The shock will smack away at clutch plates and gears and cause major wear. It also allows a little more load on the engine to help in it's case of stopping bore glazing.
If the bore is startign to glaze, all is not lost. It is quite possible to reverse this if it has not gone too far. Simply work the engine hard from cold from now on. Instead of sitting on a mooring all the time, you need to cast off and get the engien under good hard load ASAP before it has a chance to warm up. Allow it to come up to temp and then come back to the mooring. Some time of doing this can help seat in those rings again.

White smoke at start can be a sign of unburn't diesel. Unfortunatly it is not easy to diagnose any thing definate from here. But it is most likely just a few burst before the cylinders fire, it could be one or more cylinders taking a little extra to fire, it could be diesel lying in the pot from a leacky injector (source of problem) or it could be steam from water in the exhaust, or it could be none of the above.

Diesel oil will go black quickly. It's the detergent in the oil that is doing it's job in flusing away the carbon. If water is getting into the oil, then the oil will go grey'ish white and often a greasy grey'ish white waxy gunk accumulates in the tapet cover and breather area.

[delmarrey]

Cracked head What am I thinking. It must have been thinking antifreeze.

Anyway, like Alan said. He's on the right track. And you say you replaced the pump! That's the only other place it could get in................_/)

[never monday]

You need a thermostat. It controls the flow of water so it won't overheat in balmy waters.

[delmarrey]

over heat?? If anything wouldn't it be not warming up enough.

[never monday]

No, without a thermostat or reducing sleve. The cooling water flow is too fast to absorb heat from the engine block and head. There for your not cooling and can overheat.

[Alan Wheeler]

Yep this fools many. A big mistake can be made by removing the stat thinking it will just be a case of the engine runs a little cooler. But then they find the engine boils.
However, if the removal of the stat HAS lowered the eng temp and if the engine does operate too cold, that can also lead to poorly burn't fuel seeping down the pot walls.

[CSY Man]

Had the same on my 4-108 when I bought the boat 8 years ago.

(NO, not the same engine as the Westerbeke 4-107)

In my case I had the oil analyzed as part of the survey and got an urgent telegram from the oil guy: He said, Do NOT run the engine, you have 6 % fuel in the lube oil.

That kind of ratio would cut down on lubrication among other things.
Long story short, it was a leaking lift pump.

So, don't run the engine unless ya have an oil sample checked.
It cost right around $20.00 here in Florida and it could save ya $8K.

As for not worrying about a thermostat...?
Wish I was that casual, and I hope ya get away with it..

[BilgeRat]

Originally Posted by never monday

No, without a thermostat or reducing sleve. The cooling water flow is too fast to absorb heat from the engine block and head. There for your not cooling and can overheat.

Well, I would disagree. Unless there was air in the system, no matter how fast the water goes through there its going to be heat transfer.

Try throwing a cup of water at a scorching hot pan. Then do the same with a bucket of water. Which do you think will cool it the most? That's why water is used to cool rather then oil. Oil is a more even vehicle for warming and heat distrabution. But water draws quickly. Like pouring water down a hot dry radiator.

Personally, I'd be more worried about the motor not reaching the proper temp. Diesels run best when the exhaust is at the proper temp. Cold fuel is a waste of energy.

Yours aye!

[never monday]

Originally Posted by BilgeRat

Well, I would disagree. Unless there was air in the system, no matter how fast the water goes through there its going to be heat transfer.

Try throwing a cup of water at a scorching hot pan. Then do the same with a bucket of water. Which do you think will cool it the most? That's why water is used to cool rather then oil. Oil is a more even vehicle for warming and heat distrabution. But water draws quickly. Like pouring water down a hot dry radiator.

Personally, I'd be more worried about the motor not reaching the proper temp. Diesels run best when the exhaust is at the proper temp. Cold fuel is a waste of energy.

Yours aye!

ok, want to pulls yours and be the beta tester? I've done it in my youth. I know the potential.