one cylinder bad

[mestrezat]

A fellow cruiser just returned to his boat after two years to find his engine won't start. Final diagnosis was one cylinder had rust in it while the other three were just fine. Is in the process of repairing but can't seem to figure out how just one cylinder got fouled. It's a Yanmar engine. Afraid it might happen again.
Any thoughts?

[MBWhite]

The most common cause would be an open exhaust and an open exhaust valve allowing moisture into that cylinder.

There can be other causes- cracked block, cracked head, head gasket failure but if it was running and then parked for a couple of years without a thorough winterization that is what I would suspect first. Look on the backside of the exhaust valve during the teardown and also the valve seat to see if they have corrosion on them. They might need to be lapped or otherwise resurfaced in addition to the cylinder clean out.

Was a yard hired to winterize the boat in the first place?

[MBWhite]

Oops just noticed you are in Malaysia, so I guess we can rule out a cracked head due to poor winterization!

[Ex-Calif]

Originally Posted by mestrezat

A fellow cruiser just returned to his boat after two years to find his engine won't start. Final diagnosis was one cylinder had rust in it while the other three were just fine. Is in the process of repairing but can't seem to figure out how just one cylinder got fouled. It's a Yanmar engine. Afraid it might happen again.
Any thoughts?

Basically don't leave the engine sitting for two years...

As to how one cylinder got fouled?

Well on a 4-banger one cylinder will be compressing (both valves closed), one will be powering (both valves closed), one will be intaking (exhaust closed) and one will be exhausting (exhaust open)

I am guessing it's the one with the open exhaust valve that is open to the relatively dirty and corrosive exhaust byproducts in the exhaust system. But you'll never know.

As to why if didn't start, presuming it did when it was left idle, it could be anything from a gummy injector pump to bad fuel, to failed lift pump.

Leaving these things idle for 2 years is not a good idea.

[mestrezat]

I talked to him this morning after getting the replies. They(mechanic and owner) got it started. When they pushed the start button, the engine turned but wouldn't start so the mechanic turned switches in the boat to combine all the batteries in to one large bank and it started and has started ever since. Now there is no raw water going through the engine so they are going after that problem today. I suggested they look at the through hull to see if it's crusted over. I've been here 3.5 months and when I dove on the bottom the other day, any thing that was metal was solidly encrusted in inch thick+ life forms. Couldn't even see the intake for my water maker. Never have seen such growth in any marina I've ever been in. The owner tells me they had the bottom cleaned two weeks ago and blew pressurized air down the intake and bubbles came out along side the boat. They had pulled the impeller a short time ago and it appeared to be fine.
As to the cylinder problem, not only was there rust in there but also some debris as well. When this first came up, I also thought it was the valves letting humidity in but wanted to throw it out to more experienced folks to get you input.
Any thoughts about the raw water problem?

[Ex-Calif]

Wow - These guys are nuts - It sounds like.

It's been in the water alone for 2 years? Holy cow!

There was a thread here recently about recommissioning a diesel. We ended up with a pretty good list of things to do and it sounds like these guys aren't doing many of them - LOL...

Check/change the oil, filters etc
Check/change the fuel, filters etc
Check/change engine belts
Check/change fresh water fluid, cap etc
Check/change the raw impeller, inlet strainer thru hulls, disconnect supply to pump and check for water flow - reattach
Remove injectors for cleaning
While injector are out rotate engine, spray light coating of oil in cylinders
Remove water supply from riser
Charge batteries
Run starter and inspect for water flow to riser
Check for oil pressure
Check for fuel from injector lines
Attach water hose to riser
Check/clean exhaust riser, exhaust mixer etc.
Attempt start

There may be a few more steps. Maybe others will chine in...

[MBWhite]

Originally Posted by Ex-Calif

Wow - These guys are nuts - It sounds like.

It's been in the water alone for 2 years? Holy cow!

There was a thread here recently about recommissioning a diesel. We ended up with a pretty good list of things to do and it sounds like these guys aren't doing many of them - LOL...

Check/change the oil, filters etc
Check/change the fuel, filters etc
Check/change engine belts
Check/change fresh water fluid, cap etc
Check/change the raw impeller, inlet strainer thru hulls, disconnect supply to pump and check for water flow - reattach
Remove injectors for cleaning
While injector are out rotate engine, spray light coating of oil in cylinders
Remove water supply from riser
Charge batteries
Run starter and inspect for water flow to riser
Check for oil pressure
Check for fuel from injector lines
Attach water hose to riser
Check/clean exhaust riser, exhaust mixer etc.
Attempt start

There may be a few more steps. Maybe others will chine in...

My gut feeling is that the owner probably does not have the budget to do a thorough recommissioning. Plus, we do not know why the boat was left to begin with, maybe there was a death in the family and he had to go home in a hurry and once halfway around the planet all the myriad of "important" things that need to get done all conspire to keep you from what you were doing before, then next thing you know 3 weeks has turned into two years...

Anyway, I've had a few instances in my life where I was getting fed up with some lazy or irresponsible ass only to realize later they were just normal people dealing with some terrible situations not of their own making that I wouldn't have wished on anyone.

At any rate, to get back to the water pump issue I am now guessing that the boat has been in the water all of this time. It is possible that something has made a home in the cooling intake. OOps, let me back up a bit here.... If you have no cooling water from the pump output you can only have 3 things that cause this (well 4, if there is a mechanical issue preventing the impeller from turning) But either the impeller is faulty/worn/disintegrated, the water intake is obstructed, or the cooling water supply line has a vacuum leak somewhere.

An inspection will show if the impeller is bad and just bump the starter or turn the pulley if belt drive to verify it turns. This may seem simple but I once installed a new water pump to fix an overheat which it did not do, long story short is the new impeller spun on the shaft which took me several days (hey I was green back then!) to figure out after checking out every other possibility.

If there is a vacuum leak in the line it will seep water. This would have been noticed by now so I do not think it is the cause but it needs mentioning for the sake of completeness.

That leaves an obstruction to be the most likely cause. If possible try to snake a wire down the line. Hopefully the intake has a seacock on it, close that and remove the hose from there and put a straight section that goes above the water line if need be. If there is a tough blockage and this is legal to do where you are, try pouring white vinegar down it to loosen up any barnacles or mussels, etc that may have made a home in there.

I once had to fix an overheating engine that turned out to be caused by a cigarette filter of all things. It made its way into the intake of a race boat and past the seacock but jammed up at the fitting. It was not dislodged by air and in fact passed all the bubbles too but when the pump started sucking it would seal up the intake, and it was just a tiny regular cigarette filter....

Anyway, I'd try using a section of 3/16" steel cable if possible, if you can get that through maybe chuck it in a cordless drill and let it rattle around a little bit but do not do the drill thing if it is still hooked up to the cooling lines as there is the possibility of eating away at the inside of a line leading to a midnight surprise at some point in the future. And as mentioned, I'd suggest some vinegar soaking if it is allowed.

Best of luck!

Mark

[mestrezat]

The solution(according to the mechanic) was a faulty seal on the raw water filter. I was sucking air into the lines. I would have thought that plenty of water would have still gotten pulled in but maybe not. As of now, he has water coming out his exhaust.
Now his alternator has died. If he didn't have bad luck, he wouldn't have any!

[Ex-Calif]

Originally Posted by mestrezat

The solution(according to the mechanic) was a faulty seal on the raw water filter. I was sucking air into the lines. I would have thought that plenty of water would have still gotten pulled in but maybe not. As of now, he has water coming out his exhaust.
Now his alternator has died. If he didn't have bad luck, he wouldn't have any!

Seems like he is slowly working his way through my list - LOL...

Boats - Pay me now or pay me tomorrow.

[Arthur Garfield]

Like Ex-Calif ---- WOW,2 years sitting in tropical waters !

With that I figure none or little sealing out humidity.I expect much more to be "looked after" with this vessel.

All the Best !

[mestrezat]

I found out his freezer/frig has lost all it's freon. Gave him a can of the stuff(had since Mexico) and loaned him my hose to put it in. Let's see what we find tomorrow. At least the couple has a good attitude about it. I think I'd be tearing my hair out by now but at least he's in a good marina that has help available locally and it's not breaking the bank being here. I think I'd have hired a man to visit the boat and at the least start the engine once every two weeks or so. On the plus side, he did have an air conditioner set on a timer to run most days for a couple of hours so mold wasn't an issue when they get back.

[MBWhite]

Just make sure it is the right type of refrigerant before he puts it in, most likely it will be R134 but can be R12 or R22 (or others, depends on teh system). Also have him make sure it has leaked out, if the unit was sealed it is very rare for them to leak.