The Monster Returns

[FourPoints]

I'm starting to lean to a diagnosis of worn piston rings and cylinder liners which when the oil thins allow blow -by compression to increase crankcase pressure and pushes the dipstick up forcing the oil out.

logically this makes a lot of sense. Engine gets hot while running hard pushing against the wind into heavy seas, as such the blowby increases to the point of over pressuring the crankcase faster than the vent can handle (add the chop and it presumably gets restricted from spraying oil to make things worse), and you suddenly build pressure until it blows out anything it can easily dislodge or leak past. Explains the dislodged dipstick, the inermitent problems, and most of all makes sense for an older engine that has pushed through many miles of sea over the last year and a half (and before).

 

[anchorclanker]

Rather than jumping to conclusions, sight unseen, there needs to be a logical approach to troubleshooting engine problems. A comprehensive approach is usually more efficient and cost effective in the long run. As I said elsewhere, IMHO the engine should have been removed to do the head gasket, and at that time all gaskets, seals, anything that could leak coolant or raw water or oil, should have been replaced, so they wont bite back later. Were past that now so we move on.

I had a kubota diesel powered generator in our last motorhome. The dip stick had a bonded rubber seal at the top of the stick where it fit the tube. It was 20 years old and if not pushed down firmly would push itself out and throw oil all over. I had a similar problem with a 300D Mercedes. Diesels produce a lot more turbulence in the crankcase and is why many have such large crankcase ventilation systems and rubber seals on their dipsticks. If the seal on that dipstick is aged, it could push out enough to spray oil on a brand new engine just as easily as on an old one.

A compression test would rule out the rings, then we wouldnt have to discuss it further. After 25 hours, the engine should be stabilized. Because the compression should be checked on a hot engine, that would also be a good time to retorque the head. Alternatively, a quick test is removing the oil cap while running (idling), noting if there is any excessive blowby. If its no more than baby breath on your hand, there is no need to look further, the rings are working fine. If its chugging out a lot of volume thats another story.

It can get very frustrating trying to solve problems that arise after major engine work like this. And yes, mechanics are much like doctors throwing round different diagnosis. But unlike doctors who are forced to be educated and tested, any moron can call themselves a mechanic. Often times it is best to bypass all the BS shoot from the hip guesses and speak directly with a factory tech or someone highly recommended, a real guru. But they are going to ask for compression numbers so you may as well do it before proceeding in that direction.

 

[Rick486]

For whatever it may be worth, I had an Westerbeke 4-107 spew 5 Qts of oil out of the oil pressure sender. It was very difficult to trouble shoot but once a mechanic came aboard and we refilled the engine with oil and started her up, he spotted an almost invisible stream of 40 psi oil spewing out from the sensor at a crazy angle and the steam was ricocheted off various components so it was very difficult to pin point. He had seen that happen previously so he was armed with experience of where to look.

 

[Bob Mack]

Roger:

For what it's worth, my oil leak I discussed in my prior post was solved by Drew (Andrew) from Noank Village Boatyard, who may still be very close to you. It might be worth getting him to take a quick look, if only to confirm your solution.

Best of luck. If you stop up the CT River again you might want to consider the bottom of Seldon Creek, just up from Hamburg Cove, which is a beautiful spot this time of year. I'm assuming you will be heading in the correct direction soon.

 

[Benny17441]

I don't think the bungee cord nor using less oil will improve the situation any. Neither leads to the root of the problem. Why all of a sudden the high angle of the engine becomes an issue when prior to that the boat came down to Florida and went half way up to the Chesapeake with no problems. Building up of crankcase pressure seems to be the issue and unless it is resolved the problems are bound to continue. The cost and frustration level if allowed to rise may doom the boat.

 

[Roger Long]

The cost and frustration level if allowed to rise may doom the boat.

Hauling and not going south this year will doom the boat anyway so I am going to carry on.

I tried to get a compression test today but can't get one for a week so I'm going to try the traveling diagnosis. Oil consumption on this engine is very, very low, even for a fairly new engine. It starts and runs like it was new. It's hard to believe there is anything wrong with the rings.

One wild card is the extreme shaft angle, well over Yanmar specs. Both of my oil pump outs that didn't involve water intrusion and head gasket failure have been associated with heavy pitching while motoring. The mechanics next door have seen the same problems on otherwise sound engines that were mounted at high angles in powerboats.

If nothing else, continuing on will provide entertainment for you all. I'm planning on having the mechanics in Solomons, MD that diagnosed the first dipstick expulsion problem go over the engine thoroughly, replace the high pressure oil line, and re-torque the head.

I'm running 15W40 oil already.

 

[Roger Long]

As I said elsewhere, IMHO the engine should have been removed to do the head gasket, and at that time all gaskets, seals, anything that could leak coolant or raw water or oil, should have been replaced, so they wont bite back later.

I agree but, as they say, "If wishes were horses..." Removing the engine would have meant not going south this year and probably selling the boat and getting another hobby. It's now my primary home and I've got to get it south. I wishes were dollars....

 

[anchorclanker]

I agree but, as they say, "If wishes were horses..." Removing the engine would have meant not going south this year and probably selling the boat and getting another hobby. It's now my primary home and I've got to get it south. I wishes were dollars....

Hey, I hear ya. A mans gotta do what a mans gotta do. I was just sayin what "should" have been done, in a perfect world.

I honestly feel you have a good handle on it and will be able to deal with it. I dont think the rings suddenly failed, I think what happened was a lot of stuff got screwed with and now your running around stamping out little fires. Ive had and seen lots of engines go through similar fits after some major surgery. It should be fine once you get everything settled.

 

[Benny17441]

I'm still puzzled by the sporadic elevated cranckcase pressure. I don't recall you mentioning details about the cooling system. Engine overheating could be the cause for elevated cranckase pressure and also for the failed head gasket. Engine overheating could come as a result of sustained running under heavy load or diminished flow in the cooling system. A partial blockage or a collapsing soft hose could be a cause. Make sure that the sending unit is activatin the buzzer alarm at its preset setting and keep an eye on the exaust flow and engine temperature. Like I said before engine overheating can thin out the oil and provoke compression blow-by. If you have checked the cooling system and everything is OK then move on to a compression test. In the meantime you may want to alter your ways and sail more and try not to overload the engine. Good luck.

 

[Jimm]

..

If nothing else, continuing on will provide entertainment for you all. I'm planning on having the mechanics in Solomons, MD that diagnosed the first dipstick expulsion problem go over the engine thoroughly, replace the high pressure oil line, and re-torque the head.

I'm running 15W40 oil already.

There's a first rate diesel mechanic who keep my engine humming here in Annapolis if the need arises - and thanks for the 'entertainment'

 

[Roger Long]

I'm still puzzled by the sporadic elevated cranckcase pressure.

Me too. The oil pumping seems to occur in sudden fast spurts. No one has told me rings could behave that way. It they are leaking they are leaking. Remember, this oil stayed as clean as right out the can for nearly 20 hours. The engine burns oil at about the rate of some new engines. The engine runs and starts like a new one and there is no exhaust smoke. Just the light grey of a raw water cooled engine running at the low temp forced by that kind of cooling system.

I do have quite a bit more than a baby's breath of pulsing outflow from the oil fill. If this engine were installed at a shaft angle within Yanmar specs, it definitely would be coming out of the boat for a rebuild. However, my mechanic and the three next door (with lots of high shaft angle installation experience) both tell me that the high crankcase pressure and oil pumping are common with that situation.

There was no sign of any past overheating when we looked inside the head and cylinders. Since it is raw water cooled, there is little that can go wrong with the cooling system. I have a water flow alarm just downstream of the strainer. It's very sensitive and goes off when I bring idle below 1000. I'll know about the slightest water flow disruption.

The one thing different about the operation before this last episode is that the mechanic who put in the new head gasket put in more oil than I have been doing. That may be the one thing he got wrong. I put the same amount in at the last fill. The guys next door think the amount I was running with normally was too much for an engine at this angle. The dipstick is at the aft end of the case so they think mid way between the top and bottom marks is probably what I should consider the top mark.

On the big engines I used to be involved with on sea trials, most came with a blank dipstick. The techs would carefully fill them and do some other tests and then file marks on the dipsticks. These were all high angle installations. I usually drew them right at the manufacturer's limit with some allowance for running trim.

All the breather system hoses are new. Even with all that sloshing and pumping, no liquid went into the breather line. I've confirmed that it is clear and unobstructed several times.

I'm heading down river soon with the oil about one quart down from where I used to run and maybe a quart and a half down from where it pumped out last night. Watch the SPOT to see how it works out.

Oh, yeah, I've got a big dam of oilsorb pads next to the engine beds now just in case.

Get a metal spring (Ace hardware?), though, because the heat and oily atmosphere will kill that bungy in a few weeks..

Since I will be checking the dipstick every 30-40 seconds from here on, I'm sure that I will spot any deterioration of the bungy in plenty of time to replace it.

 

[kloudie1]

You are probably correct in your observation, Roger.. If you look at the crankcase and oil pan, as the engine angle increases, the aft crankpin gets closer to the oil level .. you're losing effective oil pan volume as the engine is tilted up.. Probably close and that coupled with heavy pitching is getting the aft crank pin and con rod end into the oil and severely beating it about .. It seems like the breather should be staying free, but it may not ... or since you didn't find oil in it, it may be staying clear and the oil whirl from the crank hitting oil doing something without the vent getting to do anything about it.. I dunno.. But I think you nailed it.. High crank angle, high oil level, and heavy pitching..or rolling.. Good luck, Roger..

 

[rtshinn]

Fair winds and smooth sailing Roger, and thanks for the morbidly fascinating entertainment! :>)

 

[anchorclanker]

If your oil is already close to hitting the crank and you start pitching around a lot its going to start churning oil like mad. It can whip it into a foam, increasing its volume. The air whipped into the oil can lower oil pressure enough to light an idiot light or trigger a low pressure warning. And it can push the dipstick out. Sound familiar?

Skid loaders, which do a lot of fast maneuvers and acceleration/deceleration (similar to a wildly pitching boat) have dip sticks with screw type expanding plugs at the top, so they cannot blow out. Forget it loose and youll have a mess. BTDT. But they also have a good windage tray, and deep oil sumps with dropped pickups to keep the oil level way below the crank. Do these motors even have a windage tray?

Baby breath? I cant tell what seems excessive blowby from here. All diesels have some. I have a 16 HP two banger Yanmar in one of my tractors and can feel a light pulsation of air but its not excessive, doesnt use oil, burns clean. But whats light to me is kind of subjective eh? In any case I doubt your rings suddenly died at the 20 hour mark, I think you had oil whipping going on.

I would certainly replace that line, but I think if you lower the oil level as your thinking, your good to go. I would also replace the dip stick seal and consider securing the stick down, maybe even with a twist of wire, your bound to find rough water again.

 

[xcyz]

We only wished it was as simple as what you and Anchorclanker state. I on the other hand don't think the oil is being whipped up into a foam, reducing oil pressure or even the engine being at the incorrect angle.

Roger,
It sounds as if you just recently purchased the boat or repowered it recently, yes? If you have owned the boat with any length of time you would know the motors running characteristics. Haven't you ever run the motor before in sloppy sea's? Haven't you always filled the oil to the markings on the dip stick? Except for the last 10 +/- days, has this issue ever happen before? If the answer is "yes", then maybe you're on to something but if the answer is "no", then keep looking...

I guess I'm just surprised that a Yanmar mechanic isn't able to figure this out, sounds as if there's a lot of guessing going on.

Wish you all the best...

 

[Stu Jackson]

RG, FYI, Roger has been writing about his travels in his part of the Forum for over a year. He described his trip, last year, from Maine down to Florida and back. Most of us have been following his travels, perhaps you have not. His engine has been in his boat since he bought the boat and he had engine "issues" last year coming north through the ICW. You might be interested to read his travels in his voluminous earlier posts.

 

[xcyz]

Thanks Stu, I'll read the posts from his forum and catch up..

I'm just as frustrated as the rest. Roger has taken his boat to several engine mechanics and the issues still exist. Seems like as if he's getting nickle'd-&-dime'd to death... This can definitely take all the fun out of boat traveling.

 

[anchorclanker]

RG, and anyone else having trouble with this. Yanmar didnt build the boat. The boat builder selected the powerplant, and installed it at an angle that is beyond Yanmars suggestions. Read that again, the engine is tilted beyond the manufactures recommendations. Had the engne failed early in life due to a lubrication failure, and a factory tech noted the engine was angled beyond outside its suggested range, they would likely have denied warrantee.

The engine is made to sit basically upright, and gravity holds the oil in the sump. The oil pan is made in such way as to hold a specified amount of oil, and keep that oil way out of the way of the crankshaft at the maximum range of tilt. But it wont work sideways, and it wont work upside down.

Race cars that run on a track, often have to make drastic alterations to the oil pan if they start doing hard cornering. As cars advance in capability, creating high G forces in long sweeping turns, no amount of creativity can prevent oil starvation or oil whip. Thats where we begin to see dry sump systems. Scavenge pumps in the pan continuously draw oil away, and pump it to a tank. A second, pressure pump, then feeds the oil back into the engines oil galleys, where it goes where it would normally go, and falls off into the sump... Aerobatic aircraft have similar systems, allowing them to fly upside down. Some advanced designs have multiple scavenge pumps to keep the sump and crankshaft clear of oil.

What we believe is happening here is his engine is tilted so far, that if the oil is filled to the line on the stick, the oil is almost touching the crank. In calm waters he hasnt had a problem. But in rough seas, the engine is getting tilted even further. Each time it does, the crank whips the oil. It can take a while, but soon the oil becomes an air entrained soup. It gains volume, and now even when the boat is level, the whipping continues. Only now its constant. The crankcase can no longer breath properly. Crankcase pressure builds beyond normal. It starts trying to push oil out anywhere it can. And because the oil is full of air, oil pressure drops. Now we have a oil warning going off. We have oil all over the engine. But after its shut down, after the oil settles and the mess is cleaned up, we cant really find anything wrong. He starts it up, it idles fine, it runs just fine at full power, and it seems a big mystery. Until hes back in rough water with a full sump of oil and running hard.

 

[Stu Jackson]

Great summary, ac.

 

[anchorclanker]

I sure hope its that simple. I believe it is but only time can prove it out.

At least he has hung in there and fought a good fight. Seems a great number would have run off and bought a new engine, and who would blame them. But it would sure suck if it didn't solve the problem.

Remember guys, mechanics arent Gods. We only know what we read and learn. And I would be lying if I said I haven't learned a few things watching this story unfold. Its been a real head scratcher thats for sure.