Yanmar Problems

[CAELESTIS]

Originally Posted by bstreep

Turbos can be rebuilt rather than replaced. These are very common turbos (they are used on diesel automobile engines all over the world - I found out about using EZ Off from a VW forum). Rebuild kits aren't that expensive, and it's not that hard to do.

Yes, I am having it rebuilt at $550. The Yanmars use a IHI turbo (at least on the small engines). I will also pull the injectors and have them cleaned/bench tested. Just like the Clint Eastwood movie . . .for a few dollars more.

[noelex 77]

Just out of interest a met a German cruiser today with a 56 foot Oyster. He got a rope around his dinghy prop just before he got back to his boat. In the 30 knot wind he could not row into wind so he needed a rescue, after we sorted the problem we sat down and had a coffee.
He told me in his other boat (doesn't everyone have two yachts?) had a Yanmar turbo engine. The turbo had given him endless trouble from new. He got a specialist Yanmar expert who suggested just replacing the turbo with a clear pipe and accepting the loss in horsepower.
Now he, like me, never expected this to work at all, fuel metering all wrong etc, but the mechanic assured him that he had done it many times.
3 years later he said the engine ran beautifully without the turbo.

Make of this tale what you will. It still sounds crazy to me, but this guy was smart, meticulous and assured me it worked great. The normally aspirated Yanmar 54 and the turbo 75 motors are very close in design it may just be a worthwhile emergency, or troubleshooting option even if you don't make the change permanently.

[Sailor g]

Originally Posted by bstreep

Turbos can be rebuilt rather than replaced. These are very common turbos (they are used on diesel automobile engines all over the world - I found out about using EZ Off from a VW forum). Rebuild kits aren't that expensive, and it's not that hard to do.

EZ Off? Never heard of using that. Sounds interesting. Could your please tell more?

[bstreep]

Originally Posted by Sailor g

EZ Off? Never heard of using that. Sounds interesting. Could your please tell more?

OK, disclaimer follows: DO NOT DO THIS TO YOUR ENGINE. I'm not responsible for this bad advice:

What the VW guys do is they put their cars on ramps, don a full protective suit, fire up the diesel, crawl under the car, and spray EZ Off Oven Clean (the old nasty stuff, not the non-toxic stuff) into the intake and through the turbo. It removes the carbon from the turbo without removal. I can't imagine what it does to the rest of the engine and components. Not something I'd try.

HOWEVER. What I did is THIS: Remove the turbo (it takes a couple of hours), clean with EZ Off Oven Cleaner, worked like a charm. Removes all of the carbon quickly and easily. That was a year and a half ago - still runs great!

[Bash]

Originally Posted by bstreep

OK, disclaimer follows: DO NOT DO THIS TO YOUR ENGINE. I'm not responsible for this bad advice:

What the VW guys do is they put their cars on ramps, don a full protective suit, fire up the diesel, crawl under the car, and spray EZ Off Oven Clean (the old nasty stuff, not the non-toxic stuff) into the intake and through the turbo. It removes the carbon from the turbo without removal. I can't imagine what it does to the rest of the engine and components. Not something I'd try.

HOWEVER. What I did is THIS: Remove the turbo (it takes a couple of hours), clean with EZ Off Oven Cleaner, worked like a charm. Removes all of the carbon quickly and easily. That was a year and a half ago - still runs great!

Yanmar makes a product called "Turbowash" that works while the engine is running.

Google it.

[bstreep]

Originally Posted by Bash

Yanmar makes a product called "Turbowash" that works while the engine is running.

Google it.

I have it, and now I use it regularly. It's quite a bit less noxious than EZ Off. And I used a bunch of it before pulling the turbo.

I could be wrong, but the Yanmar Turbo Wash smells and feels like "Fantasitic" cleaner.

[Dockhead]

Originally Posted by hpeer

I just saw this thread. I had a similar thread running in June as I had a similar problem. 4JH4-TE. Would run up to 1,800 load or no load. Sent the pump to a rebuild shop, they said that although it was dirty there was nothing wrong. They cleaned it, checked adjustments, and returned it.

Problem solved.

My conclusion was that something was mucking with the governor bit of the pump.

I contend that it is a misnomer to call these gizmos fuel pumps. Yeah, they do that. But they do a WHOLE lot more also. I think it is far more accurate to call them MECHANICAL COMPUTERS.

2¢

More or less exactly what happened to me.

Took injection pump off and sent it for extensive and expensive diagnostics at a specialized firm. They said pump like new, no problems whatsoever. Put it back on and voilà, problem gone.

I have no idea what was going on

[Dockhead]

Originally Posted by noelex 77

Just out of interest a met a German cruiser today with a 56 foot Oyster. He got a rope around his dinghy prop just before he got back to his boat. In the 30 knot wind he could not row into wind so he needed a rescue, after we sorted the problem we sat down and had a coffee.
He told me in his other boat (doesn't everyone have two yachts?) had a Yanmar turbo engine. The turbo had given him endless trouble from new. He got a specialist Yanmar expert who suggested just replacing the turbo with a clear pipe and accepting the loss in horsepower.
Now he, like me, never expected this to work at all, fuel metering all wrong etc, but the mechanic assured him that he had done it many times.
3 years later he said the engine ran beautifully without the turbo.

Make of this tale what you will. It still sounds crazy to me, but this guy was smart, meticulous and assured me it worked great. The normally aspirated Yanmar 54 and the turbo 75 motors are very close in design it may just be a worthwhile emergency, or troubleshooting option even if you don't make the change permanently.

Why wouldn't it work? Fueling is adjusted for the extra mass of boosted intake charge by the boocon. No turbo, no pressure, no extra fuel injected.

I wouldn't try it; I need more than 54 horsepower to move my roughly 25 ton boat. Mine's the 4JH3 HTE, turbo, intercooler, 100 hp.

[CAELESTIS]

Well, my 4JH4-TE is not running yet, but the injector service said I have 3 bad injectors, and 1 marginal one. Not sure how this could happen in 490 hrs. Fuel filters were clean, and the tank is less than 2 yrs old.

[delmarrey]

Originally Posted by CAELESTIS

Well, my 4JH4-TE is not running yet, but the injector service said I have 3 bad injectors, and 1 marginal one. Not sure how this could happen in 490 hrs. Fuel filters were clean, and the tank is less than 2 yrs old.

I guess you could say the motor is broke-in now.
It seems funny (not), some yanmars run fine for hours on end and others have trouble right off. It must be the installation and who did it.

Were the fuel lines clean on installation?
Were the fuel filters sealed up in bags before being installed?
Were the injectors in a clean environment before they were installed?
And so on. These all should be under factory quality control. If anything was changed out before the motor was run there's a chance debris can get into the system causing problems. Heck, even the turbo is crap.

Is the engine room clean, free from dust? I wonder if the tractor motors are having the same problems?

[donradcliffe]

Originally Posted by CAELESTIS

Well, my 4JH4-TE is not running yet, but the injector service said I have 3 bad injectors, and 1 marginal one. Not sure how this could happen in 490 hrs. Fuel filters were clean, and the tank is less than 2 yrs old.

My first suspicion would be that at some point you got water in your fuel.

[Kenomac]

Originally Posted by svserengeti

As I reported earlier, I have had the same low rpm issues reported earlier at the beginning of this thread & in fact, the exact same symptoms.

After scratching my head, cleaning turbo chargers, etc. for 4 months now, I decided to go back to basics. As we all know, basics with regards to a diesel engine mean ----Fuel, Fuel, Fuel.

Although I fully believed that my fuel supply was 100%- I tried isolating parts of it to make sure. I bypassed the dual Racor primary filters and also the secondary yanmar filter on the engine. I ran the engine and also returned the fuel into a 5 gallon can. Lo and behold, the engine ran up to rpm's at no load and also under load. Next, I plumbed the 5 gallon diesel can to the supply side of the yanmar filer & the engine also ran fine and came up to 3600rpm under load at full throttle.

So, I have not closed the book yet, but i know that in my case, the problem lies somewhere between the fuel manifold (I have two separate tanks) and the Racor primary filter and/or fuel lines up to the secondary yanmar fuel filter on the engine.

I'll keep you posted on my progress. What really pisses me off, is that I know that fuel is almost always the problem with a diesel engine, but I naively thought that my fuel supply system was intact. The filters were clean, and there did not appear to be any leaks or air intrusion into the supply lines. Obviously, due to my earlier mentioned discovery, that is not the case. I suspect that I have air leaking somewhere into the supply lines between the manifold and the secondary filter. The other possibility is that I have a blockage somewhere in that vicinity.

I am happy to be finally chasing this problem down to a manageable outcome

Have your turbo pressure checked out. I just went through the exact same thing, fuel source and pressure checked, turbo removed and cleaned, then finally the last thing... checked the turbo output pressure. The results.... dead turbo requiring replacement. Over 1000 euros spent to diagnose, very frustrating. Our Yanmar 100hp turbo diesel engine would also run up over 3600 rpm with clean fuel from a 5 gal can. But under load would only rev to 1600 rpm... no turbo boost pressure was the problem.

Our 100hp Yanmar turbo only had 900 hours on it when the turbo failed, probably due to the incompetent delivery crew's captain who didn't rev the engine up to blow out the carbon from the exhaust manifold during a 1200 mile delivery.

[bstreep]

Just to pile on: A year and a half after pulling and cleaning our turbo, it quit again. Pulled it on Sunday, and this time took it to a shop. They cleaned it up, tested it and proclaimed "It's just fine". They did say "You need to run the crap out of this engine, to keep the turbo clean".

I just continue to conclude that a turbo doesn't belong on a sailboat engine.

[hellosailor]

EZ-Off is, or at least the traditional flavor of it is, just plain lye. Sodium hydroxide. A very good and aggressive cleaner for many things but IIRC it will also chew the hell out of some aluminum alloys, so it really should be used with care and preferably acid neutralized (since it is alkaline) if it gets on anything. Would also chew the hell out of rubber hoses and other "soft" parts.

Same thing as traditional plumbing drain cleaner, but in a paste or spray form instead of crystals.

I suppose you could send out an oil sample after using it, to see if you've really gotten it all out of an engine. Or, just change the oil to make sure of that.

[Steve W]

I wonder if EZ -Off would clean up a carboned-clogged exhaust elbow that seems to be a common issue with some Yanmars? From the descriptions above, it sounds possible the elbow could be removed, cleaned and replaced with just some labor, gaskets and EZ-Off.