oil or diesel in exhaust water from Westerbeke 8KW generator

[cwiert]

It seems like my generator is running rich. We were tied up at the Floatilla this past weekend, there were lots of boats running their generators. Mine seemed like the only one that I could smell running. My wife made me turn it off a couple times because it stunk. I also noticed a sheen in the water coming out of the exhaust. I don't know if it was oil, or unburnt diesel. I'm speculating that it's the latter.

Any ideas on what I can do at this point? Any adjustment screws anywhere? It's running good, but I just think it's running rich. Any ideas or thoughts are appreciated.

 

[cfd95]

The injector pump is what controls the timing and sends fuel to the injectors.
It could have some wear on the internals sending more fuel to one injector.
The pump probably needs to be rebuilt.
Definitely not something to play around with if you do not know what you're doing.
Your boat was built but prior to Ultra Low Sulfur Diesel Fuel, mechanical diesel injection systems needed the sulfur to lube the internal parts of the pump.
Some additive should be used like Standyne every time you fuel up.

 

[cwiert]

Thanks for the reply. The other thing I forgot to mention, is that the generator only has 78 hours on it. Yeah, really. I realize that's not a good thing. We bought it this past November, and it had 58 hours on it then. I'm not sure how that plays into anything, just figured I'd mention it.

 

[ZZ13]

Thanks for the reply. The other thing I forgot to mention, is that the generator only has 78 hours on it. Yeah, really. I realize that's not a good thing. We bought it this past November, and it had 58 hours on it then. I'm not sure how that plays into anything, just figured I'd mention it.

That's 3.2 hours per year. I think you have the record.


Sent from my iPhone using Tapatalk

 

[ttmott]

Do you have the Installation/Operator manual? It is very clear that if the break-in procedure isn't followed the unit can be damaged and will result in excessive oil consumption and smoky operation. There is a 50 hour break-in procedure to prevent an overload condition which can score the cylinder walls.
There are other fuel system adjustments including AC Frequency (running RPM), Injector rack adjustment, valve lash, fuel solenoid, and the like.
It's all in the manual...

 

[cwiert]

I do have it on the boat. I'll check it out next weekend. But it sounds like if the proper break-in procedure wasn't followed (and at 58 hours over 17 years, I'm guessing it wasn't), then I'm probably SOL without dumping a lot of money into it.

 

[ZZ13]

I do have it on the boat. I'll check it out next weekend. But it sounds like if the proper break-in procedure wasn't followed (and at 58 hours over 17 years, I'm guessing it wasn't), then I'm probably SOL without dumping a lot of money into it.

John, a brand new Westerbeke 8.0 was installed on my boat when I purchased it 2 1/2 years ago. The only 50 hour special instructions were to change the oil at 50 hours and replace a couple of on unit fuel filters, including one that normally has a 250 hour change cycle. I did that at 50 hours (actually I think I didn't get to it until the 64 hour mark) and I am at almost 300 hours now and don't have any exhaust issues. It also said to stay within 20-60% load the first ten hours and to avoid overload during the 50 hours with overload being indicated by black exhaust smoke. Frankly I didn't worry about the load the first 10 hours and my generator has never been overloaded. Probably because I never turn on the hot water heater when the generator is running.

 

[fwebster]

I think the problem might be just the opposite of overlaoading. The engine and fuel system are governed to product full power at the governed speed. Many of us tend to underload the generators or just not run them enough and that can lead to carbon fouling on the injector tips which causes droplets rather than an atomized spray pattern. Droplets don;t get fully burned which causes blue smoke and sooting on the exhaust outlet as well as the diesel smell. Droplets can also wash the lube oil off a cylinder wall which will accelerate wear.

The fix is relatively easy and inexpensive. Have the injectors pulled out and sent to a diesel specialty shop that rebuilds pumps and injectors to be pop tested. The test opens the injector and allows the technician to examine the spray pattern. A solvent is used to pump thru the injector and many times that alone cleans the injector. I had this done at about 1000 hours and the cost was $75 to test and clean all 3 injectors.......they were in spec and didn't need anything.

 

[cwiert]

Have the injectors pulled out and sent to a diesel specialty shop that rebuilds pumps and injectors to be pop tested. The test opens the injector and allows the technician to examine the spray pattern. A solvent is used to pump thru the injector and many times that alone cleans the injector. I had this done at about 1000 hours and the cost was $75 to test and clean all 3 injectors.......they were in spec and didn't need anything.

Is pulling the injectors something the avg Joe can do, or do I need a specialist to pull the injectors and then have them sent to diesel shop? I suppose often times, the specialty shop will have someone that can pull them.

Thanks for all the info.

 

[cwiert]

I think the problem might be just the opposite of overlaoading. The engine and fuel system are governed to product full power at the governed speed. Many of us tend to underload the generators or just not run them enough and that can lead to carbon fouling on the injector tips which causes droplets rather than an atomized spray pattern. Droplets don;t get fully burned which causes blue smoke and sooting on the exhaust outlet as well as the diesel smell. Droplets can also wash the lube oil off a cylinder wall which will accelerate wear.

The fix is relatively easy and inexpensive. Have the injectors pulled out and sent to a diesel specialty shop that rebuilds pumps and injectors to be pop tested. The test opens the injector and allows the technician to examine the spray pattern. A solvent is used to pump thru the injector and many times that alone cleans the injector. I had this done at about 1000 hours and the cost was $75 to test and clean all 3 injectors.......they were in spec and didn't need anything.

i wanted to follow up on this. I pulled the injectors and had them rebuilt at a diesel shop that specializes in injectors. 2 of the 3 nozzles were bad so I had all 3 replaced. I've reinstalled and the diesel sheen on the water is gone. So that's good. But I still have blue smoke and that strong diesel smell. As someone else mentioned, should I look at the pump next?

 

[Joel_MD]

The injector pump is what controls the timing and sends fuel to the injectors.
It could have some wear on the internals sending more fuel to one injector.
The pump probably needs to be rebuilt.
Definitely not something to play around with if you do not know what you're doing.
Your boat was built but prior to Ultra Low Sulfur Diesel Fuel, mechanical diesel injection systems needed the sulfur to lube the internal parts of the pump.
Some additive should be used like Standyne every time you fuel up.

This is a common misconception, that ULSD has reduced lubricity because of the lack of sulfur. Actually it's not the sulfur that was doing the lubricating in the older diesel fuels.

The way sulfur is removed from diesel fuel is through a chemical process called hydro-processing. During hydro-processing the sulfur in the fuel is removed and replaced by hydrogen. Unfortunately as hydrogen is a highly reactive element it also reacts with other components in the fuel removing the polar and aromatic compounds that provide conventional diesel fuel with adequate lubricating capability.

 

[fwebster]

The engine in this generator only has 78 hours on it. The injection pump is lubricated by the fuel it processes. Granted, it needs a lubricity additive in its fuel, but I think it is very highly unlikely that the pump has worn enough in 78 hours running time to have excessive wear due to internal lubrication. Besides, pressure bursts is what opens the injectors. When a pump fails its internal pressures decrease. If the engine is smoking, then it is getting excess fuel and it seems contradictory that excess fuel would be injected from a worn fuel pump.

I think the more likely cure of the blue smoke is engine oil. As of November 2015, the generator had only 58 hours on it. That is about 3-1/2 hours per year. that means the engine sat idle a whole lot of the time. There could be a problem with the rings not seated or a little rust on the rings. If that is the case, then running the generator will eventually solve the problem …or not. The other possible causes of the blue smoke are excess wear in the cylinders caused by the bad injectors spraying rather than atomizing the fuel or diluted lube oil caused by unburned fuel running by the pistons and into the oil. Fuel that is not properly injected hits the cylinder walls as droplets that run down the cylinder and wash the lube oil out of the space between the piston the liner. Diluted lube oil can pass the oil rings and get into the combustion chamber. A worn cylinder lets lube oil by and into the combustion process. Either way, you get blue smoke.

At this point, I think your options are limited. Run the generator and see if the blue smoke decreases or goes away. If it does not, you are looking at rebuilding the top end of the engine with new pistons, liners and rings. If you have washed out a cylinder and it is just worn, then you have the same problem that only an overhaul with new pistons, rings and liners will solve.

However, before I got excited and did something drastic, the first thing I would do would be to have the generator lube oil samples and tested by someone like Caterpillar's SOS system that will measure fuel in the oil, wear metals, soot, viscosity, etc. If that doesn't reveal an obvious direction to follow, then you are at the point that you need to involve a qualified diesel technician.

As a kind of disclaimer and warning, internet forums and youtube are great and hold a wealth of knowledge, but you have no idea if the person answering your questions has experience or is guessing. Further, none of us have seen your generator or even heard it run and we don't know what previous service has been done to the generator. For example, did you re-torque the head (you are well past the time for that service in terms of calendar time) and replace the injector seals when you removed them? Please take the above as a list of possibilities, not a definitive diagnosis of your problem.

 

[carterchapman]

To add to Frnk's suggestions, a CAT SOS kit is $13 - cheapest thing on a boat I think! I do engines and genny every year. FYI, the antifreeze test is more expensive - $32 if memory serves me correct...

 

[ttmott]

For your generator's engine there are only two adjustments and that is RPM which sets the AC power frequency (60 Hz) and injector timing. The only probably is the timing is not correct but the engine would be hard to start or not start at all.
The engine is a Mitsubishi L3E which is really a bulletproof power unit albeit correctly run in and maintained.
One known issue with the Westerbeke arrangement is, should the engine not start and cranking continues the raw water will back up the exhaust and overflow into the cylinder head and cylinders. This can corrode and break things.