Can you get Pressure in Oil Tank?

[delmarrey]

Originally Posted by Cheechako

Every vent in my boat was clogged in 3 months by little bees when I stored it in Florida once. So... maybe...

This is why they put little screens in the vents now.

.

[scoobert]

Originally Posted by cheslr

So, that diesel fuel could then get by the seals (not sure if that would be injector pump seals or what) and get into the oil.

The mechanic said the Westerbeke folks confirmed that this could happen with this setup.

So, I need to check that fuel tank vent line to make sure it is not clogged, make sure the tank valves are always set right to supply and return to the same tank, and then run the engine under load for a half hour to an hour and then check the oil level to make sure no diesel got in oil several times, and make sure this makes the smoke stop. If so, then all may be OK. Does that sound like a good next step?
Thank you all for your insight and help with this one!

no. you see the little hoses coming off each injector? the tiny rubber ones?
those are the return. if too much pressure they would blow off.
seeing as how the injector pump puts out about 2000psi in the westerbeke, and the blow off would be about 4-8psi, they would have blown off long before.
now the seal, the only seal between your oil and diesel, is on the front of the pump, by the gear drive. this is the high pressure side, not the return side.

either way, problem solved, and your engine is super clean inside(the result of running all that diesel thru your engine oil.
your back in business.

[Cheechako]

Originally Posted by delmarrey

This is why they put little screens in the vents now.

.

Yeah, evidently some of my screens were missing. (What holds them in there?) Others were clogeed up outside the screens. I guess it's something to check on old boats... kinda flys under the radar on most lists!

[cheslr]

Well, back to the drawing board I think. I went and ran the engine for a couple hours today. She still can't get past about 2400 rpm at the dock and I get the same dark smoke at higher rpms. Even as lower rpms, still have the light smoke and slight fuel sheen on the water. After running her hard, the oil level went up by a little less than 1/4" (2 hours of running). Not the amount of diesel from before that filled the sump, but that should still not be going up.

At least it now idles well even when in gear and doesn't seem to smoke when not in gear now (and will go to full 3600 rpms with WOT) - at least there is something positive here I think. Put her under load and things start to go south with smoke, etc.

I ran the engine directly from clean, new fuel in a jerry can and it did not change the behavior at all. So, it seems that I have ruled out bad fuel.

I guess I need to check the injector pump and maybe get a compression test as well to make sure all the seals, cylinders, etc. are OK. It is crazy how never ending this engine repair seems to be for a lower hour engine. I am about ready to throw her overboard to make a mooring and plop an outboard on the stern.

[scoobert]

send your current oil out for analysis.
that will answer what the extra is in the oil.

[Cap Erict3]

Run it at high idle. Loosen 1 injector line at a time. If 1 does not seem to effect speed, swap injector between cylinder that does effect speed. Rpm drop should be similar.

Problem may follow injector,

[scoobert]

quick question to all of you with this same issue, does this fuel pump need to be timed when you put it in?
i think older P-Pump style pumps do. so if you have had your pump out, or the old owner did, did you time it?

[cheslr]

The latest and greatest on this is that we did a compression test when putting on the rebuilt injectors. Two of the cylinders were perfect. Cylinder one had "zero" compression as they told me. They are checking into why now. The mechanic hopes that it is just a valve adjustment that is needed and can fix this as a best case. I know the worst case is really bad and really expensive so I am keeping my fingers crossed. Is it possible that this could be the valves that need adjusting?

The mechanic did make a funny by saying this was one sweet running 2-cylinder (it is a 3). It is weird in that it does run well - it is just that one cylinder doesn't work, spits diesel out in the exhaust, and allows diesel into the oil. Not sure how sweet that is but it as least sounds like it is running well.

Is the oil analysis the next best step then? My wallet is scared to have so much trouble$hooting going on with this thing...

[zeehag]

listen to mechanic and do not second guess him. allow him to fix engine. you will be fine.

[delmarrey]

Sounds like you have a bent or stuck valve. It's time to pull the head and do a visual. Or you could first put a stick-camera down the injector hole and have look around.

[sailorchic34]

Ah, well then. Its probably not a valve, as a leaky valve would not pressurize the crankcase. Well unless the exhaust valve was missing. In my mind I'm 90% sure you have bad rings or a bad piston. Also the injection pump is leaking fuel into the block. Bet #1 injector pump seal is leaking. That's the easy part.

I expect your going to be pulling the engine sooner or later. BTW it is possible to pull #1 piston and just run it as a two cylinder engine. Not perfect and as you found out it will not rev up as your over propped for the two firing cylinders you have now.

So pulling the head is the first/next task.

[gjordan]

If it took your mechanic this long to find a completely dead cylinder, then I would think you need a better mechanic. How many hours have you paid for already??? Not a pleasant thought, but might be needed. _____Grant.

[Cheechako]

So... just a couple of things:
1) I had an issue with a bad injector flooding one cylinder on a boat that had sat a lot for 3 years. (it had been run some) We had the injectors tested and overhauled. We did a proper compression test ( with a fitting a machinist made. My mechanic said you cant get a proper reading with a hand held compression tester on a diesel due to the high pressures.) and one cyl was very low. We ran the boat for a day after the injector rebuild. (All along the boat ran fine with 3 of 4 cyls working, but got diesel in the oil) We were in the travelift slip to have the boat pulled to pull and rebuild the one cylinder of the engine and my mechanic said he wanted to do the compression test again....when we did it that cylinder was now fine... the rings had reseated after being flooded with fuel for so long! I wonder if yours might reseat if that's the issue? how much have you run it since the injector rebuild?
2) Zero (zero?) compression sounds like a pretty bad thing like a piston broken etc. The above engine was quite low but nothing like zero.

[gjordan]

Compression testing on Diesels just requires a higher pressure gauge, rather than the standard automotive 300 PSI gauge. My old diesel gauge read to 900 PSI. The hard part is that injectors tend to be different in different brand engines, and you have to make up many different adapters. A differential compression gauge, such as used in aviation works different than a normal automotive type, in that you put pressure into the cylinder, and you can tell if the leakage is from the rings(pressure leaks to the crankcase) or from the intake valve(listen for the noise on the intake side) or from the exhaust side (listen for leakage in the exhaust system). My thoughts on a completely dead cylinder, are to remove the valve cover and rotate the engine, and see if the valves are all moving properly. A stuck valve (usually exhaust) will give you zero compression, but often times can be freed up without a top overhaul. A stuck valve will normally require the replacement of a bent pushrod, which can be done without a major teardown of the engine. A dead cylinder for any of these reasons can put diesel into the sump. Good luck with it all. _____Grant.

[Cheechako]

Yes good point. Forgot to mention one instance where I had a bent pushrod on one cylinder... not that noticeable until we started looking closely at the pushrods. In the end we thought I might have got some water int he back cylinder leading to the bent pushrod... we then improved the exhaust riser as well as replacing the pushrod.