We want to help you understand everything you need to know about Kukje diesel tractor engines and what puts them in a class all their own.
Let’s get started.
The Kukje engine is the best diesel engine available in any tractor from any manufacturer. And you likely never heard of them.
Right now this engine is featured in the TYM Tractor T474, T494 and T574 models.
When we say it is the best diesel of all --- we mean it and will back that statement up.
To get started --- let’s dive in and discuss emission systems and modern diesel engines. (This review only applies to diesel tractors in the 40-59hp range.)
Various manufacturers have had lots of ideas on how to inject diesel fuel into a combustion chamber.
There are two common methods in modern tractors.
Most mechanically fuel injected diesel engines have one high pressure fuel injection pump. It compresses the fuel and sends it to each of the cylinders individually. This is the most common way of making diesel engines work.
To meet emissions criteria --- tractor manufacturers use High Pressure Common Rail Fuel Injection. A single high pressure pump pressurizes the whole system. Each injector is tied to this “common rail.” Electronically-controlled injectors release the high pressure fuel into the cylinders. It is a great technology and offers many benefits.
Compared to mechanical systems, it falls severely short.
To make common rail work --- you need an ECM, a high pressure fuel pump, multiple sensors, electronic injectors, and a wire harness that ties it all together. If one of the systems fails --- the engine will be severely hindered or may not run.
This is a lot of complex systems to pack into a tractor that is exposed to mud, dirt, rain, and snow.
This system is also difficult to troubleshoot and repair. You must use expensive diagnostic software.
Mechanical fuel injection pump engines have not changed much. Once the battery has started the engine --- it runs without using any electricity --- if you have fuel.
Modern mechanical engines do have some conveniences such as oil shutoffs which protect the engine and save you big money if you ever run low on oil.
Those are the two basic "hearts" of a diesel engine.
Now let’s discuss emissions.
EGR valves return a portion of the engine exhaust back to the intake and reburn and reduce emissions.
They usually have EGR coolers. They cool the hot exhaust air before it reaches the intake. The valves are prone to carbon buildup, as well as mechanical and electronic failure.
EGR coolers can rot out or leak internally. This can push coolant into the engine. This causes a coolant leak. And these leaks are hard to spot.
The questions arise --- “Is the coolant going straight into the engine via a cracked head or bad head gasket? Is it merely a faulty EGR cooler?”
When this happens you need to have a skilled mechanic to properly diagnose it. You do not want to replace your head gasket when all you need is an EGR cooler.
DOC, DPF and DEF
Here are three acronyms you need to know:
DOC (Diesel Oxidation Catalyst)
DPF (Diesel Particulate Filter)
DEF (Diesel Exhaust Fluid)
DEF systems inject a urea solution into the passing exhaust gasses which lowers the NOX emissions. These systems are complicated because they involve DEF tanks, pumps, DEF injectors, NoX sensors, and heaters.
DEF can turn into a slush in cold temperatures --- so it needs to be kept warm in cold weather.
This further complicates the systems because they need to either have electrical heaters or heat exchangers. Both run on hot engine coolant.
Both DOC and DPF are supposed to reduce particulate emissions from diesel engines.
DOCs are like a car’s catalytic converter. They don’t do much and go un-noticed until they plug up and need to be replaced. They do not regen --- while DPF’s need to regen.
Regen is short for “regeneration.” This is the process of cleaning soot out of a DPF.