Westerbeke 5KW Genset Diagnostic Question

[BradC]

My Northern Lights did the same thing. After numerous bleedings of the injectors (all good). We finally as a last resort did a compression test and found that it had virtually no compression. PO (s) had not run it much and obviously had not worked it hard. All valve and cylinders were highly fouled with carbon. After valve job it now runs fine. And anytime I start it I run it for at least 45 minutes and am sure to load it up during that time to eliminate carbon buildup.

So, I pulled the new fuel solenoid completely out and running through the preheat/start cycle, it clearly works fine, pulls in and holds just like its supposed to. The old fuel did not, so clearly it needed to be replaced.

Generator, however, still would not start.

I left the solenoid out of the system and cracked open the injector HP lines to verify fuel flow. It is good now; tightened them back up and cranked the engine.

Still no joy.

Bought a compression tester, pulled the glow plugs and visually verified they worked fine. Then checked the compression.

100 in the first cylinder, 260 in the #2 and 280 in #3. CRAP. My understanding is normal compression for this engine is 385 according to the tech manual.

I'm guessing the original fuel solenoid failed sometime just before the boat was put up for sale. The PO had said the generator ran fine to the best of his knowledge when he initially put the boat up for sale, but he had not used it in a while and had not been used or started for more than a year and a half prior to me purchasing it. I bought the boat knowing the generator turned over but would not start, documented in the survey.

My guess is the rings have seized to the pistons. No evidence of head gasket issues from my limited knowledge. Oil is clean. Glow plugs had some carbon, but not what I would call excessive.

I'm assuming now that to get the generator working it will require an overhaul that I am not in a position to handle right now.

Greatly appreciate the input and persistence from Greg especially in working through the fuel solenoid issue.

Turns out I also should have followed up on WWestman's comments sooner too.

 

[Ski in NC]

Comp is low, but you may be able to get a start. With sitting, rings can stick and valves get a layer of rust. If you can get a start, that stuff can sort of clean up itself.

Are you sure the glow plugs are working? Take leads off and use a jumper to 12v to each, should see a spark. No spark, no glow. Also get a known hot battery and use thick and short cables. Glow for 20sec before cranking. Keep sea cock shut to keep from loading engine with water, open only if it starts.

Are you sure it is fueling? A little spittle out the loose inj nuts is not a conclusive test.

I've resurrected gennies in the same condition just by getting them running, loading the snot out of them on the load bank, and they came back to normal. Some did, others did need a tear down.

 

[BradC]

Comp is low, but you may be able to get a start. With sitting, rings can stick and valves get a layer of rust. If you can get a start, that stuff can sort of clean up itself.

Are you sure the glow plugs are working? Take leads off and use a jumper to 12v to each, should see a spark. No spark, no glow. Also get a known hot battery and use thick and short cables. Glow for 20sec before cranking. Keep sea cock shut to keep from loading engine with water, open only if it starts.

Are you sure it is fueling? A little spittle out the loose inj nuts is not a conclusive test.

I've resurrected gennies in the same condition just by getting them running, loading the snot out of them on the load bank, and they came back to normal. Some did, others did need a tear down.

I did test the glow plugs when they were out for the compression test and they do get hot. Ohm check is also good. The fuel at the HP couplings is more than dribbles, so my assumption is it is sufficient. I do not want to pull the injectors themselves out at this point unless absolutely necessary because I don't have new copper washers to put them back with and no real way of testing them.

On the advice of a local automotive diesel mechanic I am going to pull the glows out again today and shoot some WD40 directly into each cylinder and let it sit a day or so, then try starting again. I asked him about using starting fluid and he said that wasn't a good idea with a glow plug engine because of the risk of bending a rod or damaging a valve due to the pre-detonation likely. He said spray WD40 again instead as that can act like a safer starting fluid for diesel engines.

I'll give anything a shot at this point short. If it needs tearing down, that will be a next year project at least.

I appreciate the assistance.

 

[Ski in NC]

Agree that starting fluid is not a good idea on these. But in desperation I have used it in my shop. I won't recommend it in this case. If you do try it, use just a tiny bit. As in tiny.

I agree also with your mech that wd40 may work and is much safer. With gp's out you can also squirt some oil in gp holes (use a tube to get it past the threads) and roll engine a few times before putting gp's back in. Oil is better at sealing sticky rings than wd. Use both!!! Can also spray some wd into air intake while cranking, but like ether, minimize how much you spray in there.

Also check the valve lash, could be tight for some reason (rare, but easy to check).

When was last time this thing ran ok?

 

[BradC]

Also check the valve lash, could be tight for some reason (rare, but easy to check).

When was last time this thing ran ok?

The last time it ran from what I could get from the PO (i've only had the boat a few months) was more than a year and a half ago. After buying the boat I found the fuel solenoid was not working properly (see first half of this thread if interested) and have replaced that. Compression seems to be the only thing now keeping it from running. TT on the engine is 480hrs since new.

I have no problem doing my own work, but my only experience is on gas engines and what I've watched on youtube

What is valve lash and how do I check it? I've contemplated pulling the valve cover to at least visually inspect the top of the valves but do not have a new gasket in hand to replace it and so have not yet.

 

[Ski in NC]

Pull the rocker cover off (easy, gasket is re-usable) and rotate engine until valves on a given cylinder are closed. Should be able to fit a feeler gauge between rocker tip and top of valve. I don't know spec on that engine but most are like 0.008" intake and 0.010" exhaust. For this check, if you can fit a 0.006" feeler in each, it is close enough for a start. You will need to rotate the engine between the checks of each cylinder. You can watch valves as you rotate, watch the exh valve and when it closes go another 120deg on crank and that gets you close to firing tdc.

Also look for any rust on valve gear, that is a bad sign.

 

[BradC]

Pull the rocker cover off (easy, gasket is re-usable) and rotate engine until valves on a given cylinder are closed. Should be able to fit a feeler gauge between rocker tip and top of valve. I don't know spec on that engine but most are like 0.008" intake and 0.010" exhaust. For this check, if you can fit a 0.006" feeler in each, it is close enough for a start. You will need to rotate the engine between the checks of each cylinder. You can watch valves as you rotate, watch the exh valve and when it closes go another 120deg on crank and that gets you close to firing tdc.

Also look for any rust on valve gear, that is a bad sign.

Wilco. I do have a technical manual for this engine. I just looked, and the valve clearance is stated to be 0.10" for both exhaust and intake.

I will be out on the boat again on Thursday so may take a crack at it then, if not it will need to wait until next week.

Very much appreciate the assistance.

 

[STB]

Hi Brad,

I am just catching up on this thread now. As Ski mentioned, I'd consider your most recent test of the solenoid and commander to be A-Okay in use.

My next step wouldn't be to spray things into the engine. I don't like fixes until I have found the problem.

I might normally pull the injectors and let a shop pop-test them -- that's normally free. But, you've moved on to the step after that and done the compression test. And, the test seems to have given you a good hint about where to look. That 100 cylinder is particularly concerning.

My next step, just because it is fast and simple, would be to pull the valve cover and (a) check for bent or dislodged push-rods, and then (b) reset leaf (valve timing) while reinstalling them. Then see how it does on the compression test. Basically, what can happen is that a valve can get slightly stuck and bend the push rod. It can then wiggle lose. After that, even if the valve has loosened, the rod is still bent and/or disengaged. This could be an easy fix. Wear or a defect on the rocker or rod can also cause this. Those rods are normally cheap. And testing is just rolling them on a piece of glass or other super flat surface.

If nothing turns up there, my next step would be a leakdown test. Low compression can be something as "simple" as a head gasket! While doing the test look, listen, and feel carefully.
-- If you find gas bubbling in the coolant, that points to a head gasket (or, less likely, a cracked cylinder)
-- If air is coming out of an intake valve -- that points to the intake valve
-- If air is coming out of the exhaust or manifold -- that points to an exhaust valve

Low compression points to a problem -- but a leakdown test points to the cause.

As a last resort to diagnosis, you can try the "tricks" like pouring some oil into a cylinder before doing the compression test to see if the numbers go up, i.e. it temporarily seals leaky rings, etc.

Only after I verified that it was nothing that I could address without a tear down would I try trying to run the engine to see if it would fix itself. There is just no reason to go there if there is a bent push rod or a leaky head gasket or someone goofed up a tuneup or whatever. On a small engine like that, even a head gasket isn't a super big job.

The leakdown test really is your friend. I might even go there after a quick scan for dislodged push rods and before bothering to pull them all to see if any are bent (which necessarily means resetting valve lash during the reinstall)

 

[BradC]

hi Greg,

I don't have access to leakdown test equipment unfortunately. I think I'm going to pull the valve cover tomorrow and at least check valve clearance and visually examine the valves and springs.

I'll post my findings tomorrow evening.

 

[STB]

Hey Brad,

Leakdown test kits are available from harbor freight and Amazon for $30 - $80, with most in the ~$40 range. In addition to the kit, all you'll need is a source of air, any shop compressor will do. If you don't have a compressor, I'll bet a friend or neighbor does -- they are useful for many things.

Or, heck, you can get a basic pancake compressor at Harbor Freight for $60 and the hose for $7. I'll bet you'll find other uses for them! I end up using air staplers for upholstery, air nail guns for carpentry and remodelling, impact wrenches on automotive things, and occasionally an air grinder on metal or concrete or an air chisel on concrete or an air brush for painting or touch ups. And, well, the occasion tire inflation.

My thinking is for $100 you can get a lot of answers.

But, if you've got leaf gauges handy, then, heck, it is easy to check the push rods, rockers, and timing. I can definitely see checking those before anything else. I'm all about learning as much as possible before spending on what is demonstratedly needed.

Checking the valves is a lot more involved. Be careful on that one.

 

[BradC]

It Runs!

Well hallelujah and pass the pancakes.

Before pulling the valve cover today, for no logical reason I decided to try and start this thing one last time.

After 15 seconds of preheat and 15 seconds of cranking, it started to fire up, so I just kept cranking and held the preheat for about 10 more seconds, let go of the start while holding the preheat a few more seconds and it kept running!

I let it run for about 5 minutes then manually shut it off using the fuel rack. Replaced the fuel solenoid and started it again, this time loading it up and letting it run for about 30 minutes. Used the stop switch this time to verify everything worked as expected.

I'm guessing sitting for another couple of days with the WD40 and oil in the cylinders was enough to get the compression I needed to fire up, but who knows.

THANK YOU! to all who've contributed to this long and at time frustrating episode.

That said, it does sound to me like the valves are a bit noisy and the engine rpm seems high and I did not notice much of a change when I put on the AC/Heat and turned on all my electronics. Not ever hearing one of these run before now, I have no idea if what I am hearing is normal.

Water temp and oil pressure all looked good while things were running, and the ticking of the valves never changed for better or worse, so not sure if I'm ready to call this case closed or not.

My Honda 2000 generator is much quieter as a reference point.

Sound normal?

brad

 

[STB]

Congrats!

Generators are governed to a fixed RPM. So, the RPM should be about the same (+/- ~3% or so) regardless of idle or full load. Engine RPM is a fixed ratio to AC 60Hz.

At this point, I'd let it run with a modest load for a good long time, maybe with a healthy dose of mystery oil in the oil.

Then, after it has cleaned itself up a bit, maybe tune it up then.

Id suspect that air in the fuel lines finally got purged. But, maybe it was the wd40.

Keeo in mind -- valves need to adjusted cold, not after running.

 

[BradC]

Congrats!

Generators are governed to a fixed RPM. So, the RPM should be about the same (+/- ~3% or so) regardless of idle or full load. Engine RPM is a fixed ratio to AC 60Hz.

At this point, I'd let it run with a modest load for a good long time, maybe with a healthy dose of mystery oil in the oil.

Then, after it has cleaned itself up a bit, maybe tune it up then.

Id suspect that air in the fuel lines finally got purged. But, maybe it was the wd40.

Keep in mind -- valves need to adjusted cold, not after running.

We're going out to enjoy the leaves changing in the TN River Gorge on Sunday, so I might let the sucker run for a few hours while underway and see how things look afterwards. Change the fluids and call it good.

Thanks for all your help Greg, and to Ski for the assist too.

brad