- ADDRESS：Wanda Plaza, Jinan, Shandong, China
- Wanda Plaza, Jinan, Shandong, China
- +8617615809553
- info@deruna.com
Maintaining the correct engine temperature is critical for efficiency, performance, and longevity. The 1001421004 Thermostat is a vital engine cooling system component. It is an essential part of genuine Sinotruk howo parts for thermal management. This precision valve regulates coolant flow between the engine and radiator. The 1001421004 ensures the diesel engine reaches its optimal operating temperature quickly. It then maintains that temperature consistently under all load and environmental conditions.
Thermostat
Термостат
Termostato
The thermostat, part number 1001421004, is a temperature-sensitive valve. It is installed within the engine’s coolant passage, typically near the cylinder head. Its primary function is to block coolant flow to the radiator when the engine is cold.
This allows the engine to warm up rapidly by circulating coolant only within the engine block. Once the coolant reaches a specific temperature (e.g., 82°C or 90°C), the 1001421004 valve begins to open. It modulates flow to the radiator to dissipate excess heat.
This process maintains a stable engine temperature. It is crucial for efficient combustion, proper lubrication, and minimal emissions. The genuine 1001421004 is calibrated precisely for the SINOTRUK Howo’s engine specifications.
Optimized Fuel Efficiency & Reduced Wear
Promotes fast engine warm-up, minimizing cold-running time when fuel consumption and engine wear are highest.
Lower Exhaust Emissions
A correctly warmed engine runs cleaner, ensuring the catalytic converter or DPF operates efficiently to reduce harmful emissions.
Consistent Engine Performance & Power
Maintains ideal temperature for peak combustion efficiency, ensuring full power output and responsive throttle.
Prevents Overheating & Cooling System Stress
Accurately regulates coolant flow, preventing overheating under load and avoiding unnecessary strain on the water pump and hoses.
| Parameter / Feature | Specification / Description |
|---|---|
| OEM Part Number | 1001421004 |
| Component Name | Engine Coolant Thermostat |
| Brand & Application | SINOTRUK Howo diesel engines, integrated into the coolant housing. |
| Primary Function | Regulate engine coolant temperature by controlling flow to the radiator. |
| Opening Temperature | Precisely calibrated (e.g., 82°C, 88°C, 90°C) as per engine design requirements. |
| Type | Wax pellet-type thermostat with jiggle pin or bypass valve. |
| Construction | Brass or aluminum housing, stainless steel spring, precision wax actuator. |
| Product Condition | New, 100% Genuine OEM Part. Includes sealing gasket where applicable. |
The 1001421004 thermostat uses a reliable wax-pellet actuation system. A copper capsule contains a specially formulated wax that expands dramatically when heated. This capsule is in direct contact with the engine coolant.
When the coolant is cold, the wax is solid, and a spring holds the valve tightly closed. As coolant warms to the rated temperature, the wax melts and expands. This expansion pushes a piston that opens the main valve against the spring force.
The valve opens progressively, modulating coolant flow to the radiator. A jiggle pin or small bypass hole allows air to escape and a minimal coolant bleed. This prevents air locks and ensures smooth operation of the 1001421004 unit.
When the engine cools, the wax contracts, and the spring reseals the valve. This cycle happens continuously to maintain a narrow temperature band. The precision of this mechanism is why genuine parts are essential.
A thermostat failing in the OPEN position is a common issue. The engine will take an excessively long time to warm up. The temperature gauge will stay in the low range, even during highway driving.
This leads to poor heater performance in the cabin. Fuel consumption will increase due to prolonged cold-running operation. Engine oil may not reach optimal viscosity, accelerating component wear.
A thermostat stuck in the CLOSED position is more severe. The engine will overheat rapidly as coolant cannot reach the radiator. The temperature gauge will rise into the red zone, triggering warning lights.
Erratic temperature gauge fluctuations can indicate a sticky 1001421004 thermostat. The valve may be opening and closing inconsistently. Any of these symptoms require immediate diagnosis and replacement.
Replacing the thermostat is a moderate-difficulty task. Ensure the engine is completely cool before starting. Place a large drain pan beneath the radiator or engine block coolant drain plug.
Drain a sufficient amount of coolant to level below the thermostat housing. The 1001421004 is typically located where the upper radiator hose meets the engine. Remove the hose clamp and hose from the housing.
Unbolt the thermostat housing cover. Carefully remove the old 1001421004 thermostat and its gasket. Thoroughly clean the mating surfaces on the housing and engine block of any old gasket material.
Install the new thermostat with the correct orientation (often marked “TO RADIATOR”). Use a new gasket sealed according to instructions. Reassemble, refill with correct coolant mixture, and bleed air from the system.
Engine temperature directly affects oil performance. Cold oil is thick and does not lubricate as effectively. The 1001421004 thermostat shortens the time the engine runs with cold, inefficient oil.
Conversely, excessive heat can break down oil, reducing its viscosity and protective additives. By preventing overheating, the thermostat preserves the oil’s integrity. This extends oil change intervals and protects bearings and cylinders.
Consistent temperature also reduces thermal stress on engine components. It prevents warping of cylinder heads and damage to head gaskets. The 1001421004 is a key factor in achieving maximum engine life.
For fleet managers, this translates to lower total cost of ownership. Fewer engine repairs and longer intervals between overhauls are direct results. A simple thermostat has a major economic impact.
The 1001421004 thermostat is engineered for a wide range of operating environments. In frigid climates, its fast and reliable closure is critical. It ensures the engine can generate enough heat to reach operating temperature.
This protects against freeze-ups and ensures cabin heating is available. In scorching desert or tropical conditions, its accurate opening is vital. It must respond instantly to rising temperatures to initiate cooling.
The materials used in the genuine 1001421004 resist corrosion from coolant additives. The wax pellet formulation remains stable across extreme temperature cycles. This reliability is essential for trucks in international freight.
Using the correct temperature rating for your climate is sometimes advised. However, the OEM-specified 1001421004 is designed for the global operating range of the Howo. It is the balanced choice for most conditions.
A suspected faulty thermostat can be tested. With a cold engine, start it and feel the upper radiator hose. The hose should remain cool until the engine temperature gauge reaches the normal range.
Then, the hose should quickly become hot as the 1001421004 valve opens. If the hose gets hot immediately on a cold start, the thermostat is stuck open. If it never gets hot and the engine overheats, it’s stuck closed.
For preventative maintenance, consider replacing the thermostat during major coolant system services. This is often at 2-4 year or 200,000 km intervals. It is inexpensive insurance against overheating or poor efficiency.
Always use the recommended coolant type and mixture ratio. Contaminated or incorrect coolant can damage the thermostat’s wax pellet and cause premature failure. Follow the manufacturer’s service schedule strictly.
The Engine Thermostat, part number 1001421004, is a small yet masterful component in the SINOTRUK Howo’s cooling system. Its precise regulation of engine temperature is fundamental to achieving optimal fuel economy, minimizing emissions, and ensuring maximum engine durability.
Insist on the genuine 1001421004 thermostat to guarantee the exact opening temperature, reliable operation, and perfect fit required for heavy-duty thermal management. Protect your engine’s heart by choosing authentic OEM cooling system components for every preventative maintenance cycle.
We are a first-class heavy duty vehicles and spare parts supplier in China. which covers from engine, gearbox, cab, axle assemblies to main assembly accessories, electrical parts and other chassis parts like brake, clutch and steering parts.
A PROFESSIONAL CHINA TRUCK AND SPARE PARTS SUPPLIER
@Copyright DERUNA
