Westerbeke 4-108 starting (firing) problems

[Gabriel11]

Short story: Engine has been 50% rebuilt and it will crank but won't start.

Long story: Since the last time my westerbeke 4-108 was used and died on me because it was mixing oil and water, I have bought and installed the following parts:
Head fixed at the machine shop
New head gasket
New rocker cover & gasket
New racor filter
New oil filter
new fuel filter
new raw water pump
starter was fixed and rebuilt
new 12v pre pump for diesel
injectors repaired at the machine shop
old diesel was removed and put in new diesel
old oil was removed and put in new oil
added additives to the diesel and to the oil
Now the engine has been put back, diesel lines have been bled and it has started only three times so far. Twice on one day and a third time another day. The third and last time it started and died less than a minute after. After that I have not been able to start the engine again, it does turn and crank but it won't fire, sometimes it does get close to starting but it doesn't. I'm asking for any help or advise on how to get it going since me and the mechanic are going mad trying to find what's wrong.
My only guess would be that the rings on the pistons got wrecked. When the water and oil got really mixed the day it died the mechanic threw some degreaser in the engine with the oil so it would weaken and remove the sludge from inside the engine, after that a friend advised me that the degreaser would basically dissolve the rubber on the pistons leading to compression problems. I don't know much about mechanics so I don't how true that could be, if anyone knows I would greatly appreciate their input or feedback. I believe it is the only thing we have not changed, checked nor repaired since it would require for the engine to be dismantled.
Any information, advice or trick regarding this problem of the engine cranking but not starting will be greatly appreciated, it's been 6 months of no sailing due to this engine not functioning. 
Thanks in advance.
Gabriel

[Dale Tanski]

Gabriel,
There is no rubber involved with the pistons and no... degreaser will not hurt your compression.  The addition of degreaser was not necessary to remove the water from the oil as once the engine came up to temperature, the water would have boiled off and be gone.  How did the water get into the oil anyway?  Through the exhaust system? Simply drain out the mix while change out the engine oil.

After everything you have done to the engine, you have proved that the engine will run because it started 3 times.  How long did you run it after the first two starts?  You mentioned that it will crank and almost fire.  There are only four things that your 108 needs to run; air, fuel, high enough compression and the ability to crank fast enough to compress the air/fuel mixture and compress it until it explodes.  You did not mention where the boat is located.  How cold is it there?  Anything below 50 deg F and most diesels will have a hard time starting.  The compression of the fuel/air mixture when the engine turns over raises the temperature of the mix.  Once the diesel fuel reaches 130 deg F it will burn but it needs to get to around 400 deg F to autoignite and run the engine. 

Many 107/108's were equipped with air inlet heaters.  These are basically an electric heater located in the inlet manifold that heats the air as it is sucked into the engine.  You simply push a button that heats up the device then when you turn the engine over, the warm air mixes with the fuel and it hopefully reaches the autoignition temperature.  See if you have one.  does it work?  Are you using it?  How cold is the engine compartment?  If it is below 50 degrees F you could stick an electric heater in there for a while and improve your chances of starting.  Another method is it place an incandescent light bulb under the engine and wait hours to raise the temperature of the entire engine.  In very cold weather sucking in the flame of a lit propane torch while cranking will do wonders but you must know what you are doing.  Either is another starting aid, but again you must know what you are doing or permanent damage to the engine could occur. 

It could be that the fuel delivery system is loosing prime.  This can occur due to an air leak at a filter or fitting.  That could account for starting and running and then the next time nothing.  This is why I asked the question how long did the engine run the first two times it ran. 

During all of this cranking while attempting to start the engine, turn off your raw water.  Every time you crank the engine, raw water is sucked in, passed through the heat exchanger and dumped into the exhaust system through the exhaust mixing elbow directly after the engine.  If the engine doesn't start and run, the water keeps building up in the exhaust muffler.  The high pressure exhaust is what pushes the water up and out of the boat, With out the engine running the water would not exit the exhaust system. Eventually it will build up high enough to backflow into the exhaust manifold and back flood the engine.  This is also why I asked where the water came from in the oil to begin with. Just remember to open the raw water when the engine starts.

Let me know the answers to my questions and I maybe able to help you further.

Dale

[Gabriel11]

Hi thanks for the quick reply. My bad when I mentioned rubber I was trying to refer to the rings that go around the piston head. Thanks for clearing the degreaser issue. The first two times the engine started it ran for about a minute or so and we turned it off because we were not sure if it was lubricating correctly and because we hadn't put water and coolant in the system. First we thought it was getting the water through the head gasket, that's why it was bought new. Then it kept mixing water so we thought it was the raw water pump which was replaced. After that it kept mixing water so we went and checked the oil cooler which in fact was mixing water and oil so I had it replaced.

The boat is located in Puerto Rico, it's always over 70 deg F here. Still we have tried using the pre heater to help the engine start but not much has been accomplished.

I did not know about the back flooding issue, it has been cranked for a while with the raw water on so there might be a real possibility that the water has built up enough to backflow. I'll be checking that today. Any advice on how to drain or empty the water that has built up?

Thanks a lot Dale!

Gabriel

[Dale Tanski]

OK, you have added lots of much needed detail.  70 deg. F should be plenty warm enough.  Running a diesel one minute again proves it will run.  I am assuming it sounded like a normal health engine should, not surging, stuttering or stumbling.  All of those would indicate a fuel problem.  Here is a common issue many including myself has done many times, did you push the STOP handle back in?  It will crank, maybe even fire once or twice but will not fire completely or run. 

If that is not the case I am still leaning toward air in the fuel system.  Again, it could be sucking air from a fuel filter base seal or a fitting is loose.  It may be ingesting air while it is cranking or running or it could even get a bubble into the suction side of the fuel system while it is just sitting there.  Next time you get it started let it run.   

Keep me informed...
Dale

[Gabriel11]

Hi again, I've been trying to work on the things you told me like the priming issue, but still with no luck. The stop handle looks like it's all the way in, maybe I'll have to open it and confirm. Talking with the mechanic, he asked me if there was a way to measure the compression, so I've come here to ask since I don't know the answer.

Again, thanks in advance for the help.
Gabriel

[Dale Tanski]

Gabriel,  Its time for some tough love...  I am beginning to believe your problem is your mechanic.  If a professed engine mechanic does not know how to check compression, he needs to do something else for entertainment.  I suspects from your first post something was a miss, now I know.

Dale

[Alan E Skeldon]

Been around a lot of engines most of my life, gas/diesel. I agree with Dale. Fuel, air, spark equals combustion. After all of the new components in the rebuild I don't see you mentioning that the head or block was tested. A cracked block or cracked head will not allow a sealed combustion chamber. A $30 tool will tell you if you have a sealed combustion chamber. I would highly recommend you buy one and test your motor.