New engine for 155d???

[NelsonMountain]

Hello All,
New to the list and new to fixing my tractor. Love my yanmar 155d but it's running on one cylinder, says the mechanic, after I sunk in $500 for a fuel pump. I don't work on my own engines unfortunately. I don't know if it's worth it to get a new engine. I bought it used for $4500 at 350hrs. It now has 634hrs. I use it regularly for my 10 acres, tilling, mowing, bucket hauling...etc. since I don't do my own engine fixing and its pricey to haul it in for repair. Of course from now on I will only rely on myself for the maintenance instead of the ex. I can do the simple things.
Do I look for something else or will I run into the same problem?
Can I part it out to help with a new one?
replace engine? is it worth it? or will it be a continual repair scene?
can it sit for a year without harm before I fix it? (I'm leaving for a year or two)
Help for a good decision is appreciated.
I just discovered this forum and am learning lots , THANKS!

 

[mark777]

Finding a new or replacement engine seems quite hasty to me. Often a dropped or dead cylinder is a fuel or injector related problem that can be diagnosed and repaired easily.

Shop for a better mechanic....I think I would look for a dealer mechanic that does side work or an independent shop that's willing to work on anything is a much better solution then replacing the engine. Even when the engines are worn completely out, they are much less expensive for an entire overhaul versus another engine.

 

[kenmac]

Don't know why your mech. can't get your dead cylinder up & going. Agree with mark. Find a better mechanic

 

[NelsonMountain]

the fuel pump was replaced. He says it is getting fuel. He also said that an overhaul...or rebuild as he said would cost more than a new engine..or more than what I paid.
I know of only one more place in town that works on diesel tractors. I could take it there, but what could I say to sound intelligent because they see a woman come who doesn't know engines and see dollar signs...know what I mean?
You input is help , anything I can get.

 

[js5020]

You really need to find someone else,,,, I have never rebuilt an engine that cost more than a new one, unless there is major internal damage. Can you fill out your profile or atleast give us your state so someone can hopefully recomend an honest reputable establishment.

 

[roxynoodle]

I am a woman, too, so I know what you mean. I have learned a lot about tractors on this forum and from my neighbors, thankfully. That left me wondering if you have any good neighbors who know tractors who could take a look at it for you. They might be able to tell you exactly what's wrong or even be able to fix it for you! Or, they might know a good independent mechanic who can fix it. I have been lucky to have a lot of neighbors who know tractors and they know people like hydraulics specialists, etc. Talk to your local people and see who they know.

 

[mark777]

I am a woman, too, so I know what you mean. I have learned a lot about tractors on this forum and from my neighbors, thankfully. That left me wondering if you have any good neighbors who know tractors who could take a look at it for you. They might be able to tell you exactly what's wrong or even be able to fix it for you! Or, they might know a good independent mechanic who can fix it. I have been lucky to have a lot of neighbors who know tractors and they know people like hydraulics specialists, etc. Talk to your local people and see who they know.

There is great wisdom in your words.

NelsonMountain,

once you find that person willing to repair your engine, I would gently but firmly request a written estimate and a complete understanding that there is a dollar limit on what you're willing to spend. This does send the signal that you won't tolerate any 'padding' with the price of parts and labor.

 

[oldmech]

Hi ! I think with (If 634 hrs) your engine is good. First ask at your ( diesel)Mechanic shop to take Compression on each cylinder. If compression Good. May be one injector. if Bad compression on one cylinder may just one valve. Do not change your engine. Good luck! Oldmech

 

[rhett]

hi NelsonMountain,

that mechanic sounds like an unknowledgeable one, lazy or out to rip of the public.

it is running on one cylinder. OK, it is not seized. more than likely it is a simple fuel injector issue. but, any diesel mechanic worth his/her salt would first and foremost run a "Compression Test", simply because compression is the requirement of the diesel fuel ignition on these engines.

How Diesel Engines Work

Like a gasoline engine, a diesel is an internal combustion engine that converts chemical energy in fuel to mechanical energy that moves pistons up and down inside enclosed spaces called cylinders. The pistons are connected to the engine crankshaft, which changes their linear motion into the rotary motion needed to propel the vehicle wheels. With both gasoline and diesel engines, energy is released in a series of small explosions (combustion) as fuel reacts chemically with oxygen from the air. Diesels differ from gasoline engines primarily in the way the explosions occur. Gasoline engines start the explosions with sparks from spark plugs, whereas in diesel engines, fuel ignites on its own.

Air heats up when its compressed. This fact led German engineer Rudolf Diesel to theorize that fuel could be made to ignite spontaneously if the air inside an engine cylinders became hot enough through compression. Achieving high temperatures meant producing much greater air compression than occurs in gasoline engines, but Diesel saw that as a plus. According to his calculations, high compression should lead to high engine efficiency. Part of the reason is that compressing air concentrates fuel-burning oxygen. A fuel that has high energy content per gallon, like diesel fuel, should be able to react with most of the concentrated oxygen to deliver more punch per explosion, if it was
injected into an engines cylinders at exactly the right time. Diesel calculations were correct. As a result, although diesel engines have seen vast improvements, the basic concept of the four-stroke diesel engine has remained virtually unchanged for over 100 years. The first stroke involves drawing air into a cylinder as the piston creates space for it by moving away from the intake valve. The pistons subsequent upward swing then compresses the air, heating it at the same time. Next, fuel is injected under high pressure as the piston approaches the top of its compression stroke, igniting spontaneously as it contacts the heated air. The hot combustion gases expand, driving the piston downward in whats called the power stroke. During its return swing, the piston pushes spent gases from the cylinder, and the cycle begins again with an intake of fresh air.

So, if there is 400 psi plus compression, fuel delivery must be the problem. It could be as simple as a, loose or cracked fuel line, "vapor lock" at one injector, clogged injector or as bad as the need for an injector replacement. The fuel pump replacement seems it was unnecessary if the engine ran.

As everyone said before me, ask friends for help first, then let that path lead you to an honest qualified mechanic.

Rhett

 

[rhett]

can it sit for a year without harm before I fix it? (I'm leaving for a year or two)

Diesel Fuel has a "Shelf Life" of 18 to 24 months. If the tractor will sit idle for more than 6 months I would add a "Fuel Stabilizer". If the tractor has been idle for more than, lets say a year, empty the fuel tank and refill with fresh diesel fuel. Not pushing the "Shelf Life" limits.

Of course, all lubricants are always recommended to be changed every 6 months.
Rhett