How Long Does She Have, Doc?

[windsaloft]

Westerbeke 21 engine, 1985 manufacture.
Current Hours around 2280 total.
Indications from meticulous records and other items of prior owners is that it was well cared for, regularly serviced and run intelligently for most of its life.

There was a 15 month owner who bought and held the boat just before us (prior owners were original), didn't do much sailing but motored around a lot looks like 300 hours or so!. He paid a mechanic for "routine service."

About 100 hours ago, at 2180, prepping for a big trip, we had a reputable mechanic do a bunch of stuff that the manuals and records indicated it was time for:
- new heat exchanger (old one was shot)
- one new and two rebuilt injectors (they all failed miserably on the bench, bad spray, wrong opening pressure, afterdrip)
- valve clearances set - they weren't far off, he said.
- timing and idle set
- compressions checked -- rear/lowest cylinder was only marginal, probably got water sucked into it with 15 month owner doing some cranking on low batteries.....compressions are 425/405/370.....
- glow plugs checked and excellent
- rpm at max checked and was okay.

When all this work was done, the sooty oil problem I describe below was present, but the sooty transom was not.

So, now 100 hours later......
- engine still starts up immediately and runs like a champ
- black sooty floating stuff that smells like sooty diesel comes out and floats on the water at start, then stops
- motoring for an hour or so gets the transom somewhat black, and when you hose it off, you get a diesel sheen on the water. The transom soot is enough to make the boat need scrubbing after each few hours of motor run.
- little to no oil consumption....
- oil turns very black and sooty after only a few hours of running, even after doing a few rounds of changing it each few hours to see if we could get the sootiness out.
- engine no longer reaching full rpm despite totally clean prop.

My diagnosis is that the compression in that back cylinder is getting worse, the engine cannot make full power b/c of it, the fuel in the other cylinders is too rich b/c of the lagging cylinder, and now that the injectors are properly set, the right amount of fuel is being put in them.....and the oil is sooting b/c of blow by on the piston rings in the bad cylinder.

Question is -- engine still running well and making enough power for what we do --- but, if going to head off across the Pacific, is this a nagging problem that can go on for a long while, or.......are the oil passages in the engine quickly clogging and I'll have some kind of main bearing failure and I am an idiot to not mortgage something to pay for a repower?

Despite the dire description, the thing starts like a champ and runs quite smoothly. IT is just the sooty oil and sooty transom that has my attention, and wondering how long it has to live.

Opinions? (Local reputable mech says to let it go til it dies, but it would be rather inconvenient if that happened in, say, Tonga.

[GordMay]

Originally Posted by windsaloft

... but, if going to head off across the Pacific, is this a nagging problem that can go on for a long while ...
... Opinions? (Local reputable mech says to let it go til it dies, but it would be rather inconvenient if that happened in, say, Tonga.

There’s a certain utility in your mechanic’s, “don’t fix it, if it ain’t broke, philosophy”; but in this case (preparing for a tanspac) I’d recommend trusting your instincts, that this is a problem, just waiting (for the most inopportune time) to happen.

Even if this "nagging" problem goes on for a long while (best case scenario); you have to ask yourself how long you wish to be nagged.

Stuff happens - especially to the unprepared.
Everyone eventually has the missfortuine to get caught out in bad weather; but anyone who starts out in bad weather, is surely getting what they deserve.

***

Do as I say, not as I do

Preventative: I generally recommend that others take care of problems, and potential problems, as soon as they discover (suspect) them.

Corrective: I often delay unpleasant (including expensive ones) tasks until they worry me, or fail.

[windsaloft]

Another local reputable mech suggests: Change the oil each 10-15 hours, since you don't use it that much -- and keep going forever. Interesting idea. Of course, he is a rabid fan of the Pardey's no engine cruising.........hmmm.

[Talbot]

Change engine, or at least the rings on the dodgy cylinder.

Check how much money you can get for the engine as is, and how much the replacement would cost, then consider what would happen in the middle of a major storm if you needed the engine .

[fred]

Tough question....lots of variables.... WAG...

If anyone predicts the failure date....
I want them to pick my lotto numbers.....

What is the oil pressure?? At idle? At 2k RPMs?
Big difference??? That is as critical as compression.

The lagging cylinder is not going to improve and will get worse as the hours build.
Track the compression, is it losing a pound of pressure for every 10hrs....20hrs????
That will give you a idea how long the cyl. will last.
The soot is the unburned fuel from that cylinder and, as is, will never stop.

I've worked on engines like yours. They will run with little or no compression in 1 cylinder. Runs fine, starts right up....

Would I take it on a world cruise....NO WAY !!!

I've been out there...you do not want the lingering thought.....

When will that engine fail????

When motoring in a crowded anchorage?
Approaching a dock with very expensive mega yachts all around?
When trying to power off a lee shore?? UGH...

I'd advise you to rebuild that cylinder, you'll sleep better.

fred

[windsaloft]

when i have looked at another W21 disassembled on the bench, it seems to me that to rebuild the cylinder requires removing the engine from the boat. Both mechs I have talked with advise that --- By the time you pull, tear down, reassemble, and reinstall, and buy rebuild parts, how far off are you from the repower bill?

[fred]

""" By the time you pull, tear down, reassemble, and reinstall, and buy rebuild parts, how far off are you from the repower bill? """

Could be alot....
Get quotes.

What does a w21 cost these days???

When I do a rebuild, I do not pull the engine, just raise it high 'enuf to get the oil pan off.

To pull the engine on most boats requires cutting the deck or cabin apart always compromisig the integrity of the structure.

On a repower, lots of items must be changed or upgraded to the new engine... IE:
~ Remove deck or cabin
~ Rebuild deck or cabin
~ Motor mounts
~ Control cables
~ Cooling lines
~ Exhaust pipe
~ Fuel lines
~ Tranny?? Coupler??

The costs add up big time over a rebuild.

fred

[windsaloft]

Beta Marine.........they seem to beat Yanmar on all fronts, to include a new trannie with their engine vs hooking in to the aged Hurth and hoping for the best. Thoughts on Beta (Kubota)?

[Ex-Calif]

This seems to be a mechanical reliability versus an efficiency issue.

The sooty transom is, as you describe, unburned fuel or incomplete combustion. This could be caused by low compression.

That would be my next check.

- Cold engine compression
- Hot engine compression
- Differential compression

It seems the fuel system is sorted so I would not suspect incorrect fuel delivery.

The good news in my opinion is that this engine is not likely to "blow up." Mechanical reliability seems good. However, the concern here is that if the engine is old enough to be getting low compression the "next' potential issue is conrod lower bearings. A good mechanic with a contact stethescope might be able to pick up tapping and other noises. Once the conrod clearances start opening up the "pounding" spells a short death for the conrod. If this occurs the knocking will get quite noticeable beofre anything lets go.

If not heading out for an extended voyage I would not worry about it.

Considering your plans I would do some more investigating before making the decision. Most likely this engine would just continue to show deteriorating performance over time - 300-500-1,000 hours? - Who knows?

Ultimately you have to decide how much you value the security.

[canuck1955]

Excuse a silly question by a newbie.

Everyone mentions xxx hrs on their diesel ie I have a1982 xyz diesel with 2000 hours and have concerns because it is old???

I have a diesel rabbit with 400,000 km on it. At an average speed of 40kph thats 10000 hrs.

Do marine diesels wear out so fast that 2000 or so hours is considered a lot and the engine is tired and worn out? I have seen postings where people are talking about 1000 hrs and replacing the engine?

[Ex-Calif]

Calendar time and engine time count.

A marine diesel over 2,000 hours will have a lot more start cycles than a car. The initial start and warm up period are harder on an engine than continuous duty. i.e. city miles are harder than highway miles.

Additionally, corrosion, condensation and the salty marine environment are tough as well.

There isn't a hard and fast rule about how long your marine diesel will last.