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Engine warranty provision

Cummins offers the best warranty policy.

Cummins warranty provision

Cummins offers the best warranty repair. Authorized service dealers from Cummins play a key role in delivering warranty repairs to customers. Cummins and its dealers should strive to make customers more satisfied with their expectations.

Customer expectations for Cummins and authorized service dealers are;

  • Customer-oriented quality and service
  • Repair all faults resulting from material failure and assembly failure
  • Providing customer benefits with rapid service
  • Fair and consistent handling of all customers

The basic principles of all service procedures are;

  • Cummins expects a high level of servicing capability, such as when it comes to making products Cummins pays for repairing all faults due to poor quality or poor assembly
  • Cummins is not liable for damage caused by negligence or negligence on the part of the customer
  • The service representative must understand the customer about correct operation so that subsequent malfunctions or negligence will not occur.

Cummins delegated authority to each region in accordance with the above basic principles and procedures.

General administrative information

All Cummins products are accompanied by a warranty that is defined by Cummins and Customer's responsibilities in the event of defects resulting from material defects or improper assembly at the time of sale.

The dealer locations shall determine the repair coverage covered by Cummins if the defect is covered by warranty. The limits of the warranty range depend on the following:

  • Type of product
  • Application
  • km / hour on engine and time in service
  • Coverage extensions purchased


During warranty repair, there is a responsibility for the following breakdown between customer and Cummins.

Customer Responsibilities:

  • Customer is responsible for Customer must use and maintain in accordance with Cummins operating and maintenance instructions.
  • Customer must maintain the operating hours. If the operating time system does not work, the engine operating time is considered to be 400 hours per month for all applications.
  • Before the expiration of the applicable warranty period
    • Register the warranty to the designated Cummins dealer immediately
    • If necessary, submit a document proving the date of the warranty start
    • Make arrangements to repair the product and, if necessary, transport the engine to a place where there is repairable equipment.

Cummins & designated dealer Responsibilities: Warranty repairs must be made at an authorized dealer locations from Cummins

  • Cummins distributors and branches
  • Repairs repaired by a Cummins dealer or branch

Special failure

Fuel system repair procedures (A, B, & C series engines)

Fuel system


  • The fuel system has the same warranty as the engine
  • Periodic maintenances which are defined in the Operation and maintenance manual do not include
  • If the fuel pump is damaged by water or foreign substances, it is not included in the warranty repair

Valve adjustment

  • It does not include the definition of routine maintenance of the operating and maintenance manual. Regular maintenance is customer responsibilities.
  • Failure of gap defect after periodic maintenance period is not included in warranty repair.
  • B and C series fuel systems are guaranteed for 1 year, without limitation, by the manufacturer (BOSCH, LUCAS CAV, NIPPONDENSO, STANDYNE)

Warranty repair administration procedure

Warranty start date: The determination of the date of initiation of the warranty varies depending on the equipment application. Each local service dealers will determine the exact date of the warranty initiation, and if necessary, the owner is responsible for providing evidences of the date of initiation of the warranty.

The engine that the owner keeps is based on the date of the first installation or the first 1 year after delivery. In the case of automobile engines, the OEM (equipment maker) date purchased, and for the test equipment, the warranty start date shall be the first test date.

Engine warranty period: The warranty period of the engine is subject to the terms of contract when purchasing the product.


Electronic engine operation and maintenance instructions.

The recently developed Cummins electronic control engine differs from the conventional mechanical version. For accurate and reliable repairs, we recommend that you use a Cummins authorized service locations. There are many conditions of high temperature, high pressure, and high speed in the electronic control engine because the existing technology is applied. This requires careful management of the user. Please refer to the following.

Fuel filter

The latest fuel systems require more precise machining and durability at higher pressures. For this purpose, fuel filters are designed to filter very fine foreign substances. When using a non-genuine fuel filter, there is a risk of damaging the fuel system components due to large particles.


Modern fuel systems can be sensitive to moisture. Please check / remove the water in the fuel from time to time. It is recommended that you use the authorized gas stations where you can trust in. In particular, diesel is slightly different in Winter and Summer, so it is recommended that you do not store it for a long time.

Engine oil

Engine oil circulates inside the engine and functions as lubrication, cooling, and cleaning. As a way to distinguish engine oil, the 15W40 is about the temperature-dependent viscosity. Chemical composition and performance related items are indicated by CI/CJ, and the following alphabet (I/J) is recommended for domestic 4 seasons, 15W40. As you go backwards, it appears as a recently developed engine oil.


The rotation speed of a recently produced turbocharger are very high. Lubrication, warm-up and balance are therefore very important. In recent years, the exhaust gas temperature is also becoming higher than ever before, and management of the turbocharger is required. Sudden acceleration can cause damage to the turbocharger rotation shaft before a sufficient preheat and lubrication after starting the engine. If the engine stops in a very hot state after completion of the work, the lubricant supplied can be shut off to the turbocharger. This can damage engine and turbocharger for limited cold air. Please wait a little longer when turning the engine on or off.

Various sensors

The sensors mounted on the electronic control engine are designed to detect the engine speed and control the fuel injection amount by grasping the operating conditions. It is mainly related to the fuel system, and other parts have many compatibility with mechanical type.


In order to effectively operate the diesel engine in the winter, you need to change the operating environment of the engine appropriately. Here is going to provide some tips to improve start ability, fast preheating, fuel economy and increase uptime in terms of fuel, lubricant, inspiration, cooling water, etc., on the operation of the engine during the winter season.

Engine idling

Long-term (more than 15 minutes) no load operations of the engine is not recommended. When operating the engine at idle speeds (650 to 1,000 rpm) in winter, Fuel consumption and wear increases and it will have an adverse effect to the engine. In the low temperature state by the incomplete combustion, unburnt tar and carbon are deposited on the valve and valve guide. As a result, it causes valve sticking.

At low speed idle (650 ~ 700 rpm), the coolant temperature and flow rate are not maintained enough to heat the driver’s seat. If you cannot prevent radiant heat and radiant heat loss in winter, engine will not be able to maintain the coolant temperature and combustion temperature. Therefore, it is necessary to use sufficient auxiliary devices to prevent long idle driving.

If you need the inevitably long time idling, such as when a driver needs to sleep in the driver’s seat, and the cooling-water temperature shall maintain at least 60 ° C with enough idle rpm. If the ambient temperature is -18 °C, the speed of the engine will be about 1,200 rpm. An on-off type fan and radiator shutter must be used for this operation.

Electrical system

The battery is usually used as a power source for engine cranking. If the temperature of the battery is lowered, the ability to charge to produce the required output is also reduced. Such battery output degradation and load increase of engine cranking can cause poor engine start in winter. Cummins recommend to start normal electric system higher than -18 °C (0 °F). The ways for the battery to provide proper output is to increase the temperature of the battery or use of additional battery. The size of the starter circuit, the length and the connectivity determines the power transfer capability to the starter. Less size of the wire will be the result of higher resistance to the flow of power. If the wire is released or corrosion can be reduced more than 50% of the battery output before power is supplied to the starter.

Fuel system

The flow of diesel fuel is determined by the pour point and the cloud point of the fuel. Often the fuel is stark in the winter is called waxing phenomenon. The waxing temperature of the fuel depends on the fuel.

When the engine is operated under the cloud point of the fuel, the wax crystals circulate with the fuel and the screen & the filter are blocked. It causes higher resistance in sharply bent fuel lines and fittings.

Even if a pour point additive is used, only the size of the waxy crystals in the fuel can be reduced. It does not change the temperature at which waxing crystals are formed.

The only way to stop the waxing of the fuel is to use a low pour point fuel or maintain the temperature of the fuel over the pour point. To use fuel heaters is another way to operate engine regardless of temperature. When a fuel heater is used, it is important to consider the deterioration of fuel lubrication characteristics although the fuel temperature should be above the pour point.

The fuel system resistance at the fuel pump inlet side should not be more than 4 inches Hg (100 mm) with selected fuel heater and filter regardless of engine speed. The use of mixed fuels (for example, mixing of No.1 and No.2 diesels) can lower the waxing production temperature, but it increases fuel consumption as the calorific value of the fuel decreases together (compared to No. 2 diesel).

Mixed fuels also degrade fuel lubrication and reduce the life of fuel system components.

* Caution: Do not use alcohol or gasoline as fuel additives which becomes unstable under certain conditions, There is a risk of explosion when mixed with diesel fuel.

Lubricant system

Regarding winter driving, two important physical feature of lubricating oils used in engines are the pour point and viscosity. Viscosity is more important than anything else. The oil must flow freely within the oil pan and the engine must be able to cycle freely.

If the engine is started with the oil in the crankcase solidified, it will result in a significant engine failure by a lack of lubricant. The oil must maintain a sufficiently low pour point, so it always to be kept in a liquid state even at low temperatures. The viscosity of the oil controls the engine's friction and oil circulation. The effect of oil viscosity on the engine is as follows:

  • Starting and preheating
  • Power
  • Fuel consumption
  • Engine cooling
  • Startup wear
  • Oil consumption
  • Engine noise

The first five elements can be improved by using low viscosity oil and the other two elements can be improved with high viscous oil. The viscosity of the lubricant is one of the most important factors determining the engine's start ability.

If the viscosity is too high, cranking resistance will be increased. If the appropriate pour point and viscosity of the lubricating oil used is not ensured, you need to warm up the oil before starting the engine.

Intake Air system

Regarding the inspiratory system, both air density and air temperature should be considered. Air density increases as the ambient temperature decreases. As a result, the highest cylinder pressure increases for turbocharger engines. Increase in cylinder pressure can cause the following types of issues. 1) Block breakage 2) Leakage of head gasket 3) Excessive stress of crankshaft bearing 4) Damage of camshaft when using hydraulic engine brake 5) Relaxation or breakage of head bolt 6) Distortion of Piston ring 7) Piston breakage

There is a direct relationship btw the intake air temperature and combustion temperature. If cold intake air is entered, the combustion temperature will be lowered. When the combustion temperature is low, a part of the diesel fuel burns incompletely. Thus, the material of the incomplete combustion tar typed are deposited on the valve guide and the valve system. It is fixed when the valve is open. Unclosed valve and piston will hit and major failure occurs. In addition, the intake air of a low temperature may result in the explosion in the outside of engine so called detonation and also piston seizure.

Cooling water system

The cooling water is used as the heat transfer medium in engines but it is easy to freeze in winter. A method for lowering the freezing point of water as much as possible is to mix 60% of ethylene glycol and 40% of water approximately. The water starts to be frozen at about -50° C (-60 ° F) in this combination. In about -1°C -10°C or lower temperatures, it is suggested to do pre-heating the cooling water, or optionally use a starting aid. At below -23°C, it is recommended to use both.