5287021 5287020 4980639 5267127 Engine Drive Belt Idler Tensioner Pulley For ISF3.8

A belt tensioner is a device that applies a predetermined amount of tension to the engine's accessory drive belt (serpentine belt). Its primary function is to maintain constant, optimal tension on the belt as it wears and stretches over time. This prevents the belt from slipping, squealing, or throwing off, ensuring that critical components like the alternator, water pump, and A/C compressor operate reliably. This belt tensioner 5287021 5287020 4980639 5267127 is engineered for maximum durability and precise fitment in  ISF3.8 engines. Manufactured to meet or exceed OEM standards, it ensures optimal engine performance and a long service life under heavy-duty conditions.

Whether for full engine rebuilds or quick replacements, DDP Engine provides you with the most reliable parts at unbeatable wholesale prices.

Parameter Details
Product Name: Belt Tensioner
Part Number: 5287021 5287020 4980639 5267127

Condition: Brand New / High-Quality OEM / Aftermarket
Warranty: 6 Months / 1 Year
Engine Model:  ISF3.8

Application:

Light trucks: Commonly equipped with ISF3.8S3122 (122 hp), ISF3.8S5154 (154 hp, China V emission standard), or ISF3.8S5168 (168 hp, China V/China VI emission standard), used for urban delivery, suburban heavy-duty transport, or logistics. 

Light commercial vehicles/MPVs/pickups: Mostly use 141–154 hp China IV/China V versions, balancing power and fuel consumption.

Small construction machinery and generator sets: Some export or special vehicles use 122–154 hp China III/China IV models (such as forklifts, compressors, emergency generators). Since China III engines are no longer allowed to be registered in China, they are now mostly used in off-highway or overseas markets.

Chassis and Special Purpose Vehicles: For light-duty special purpose vehicles under 9.6 meters with blue/yellow license plates (such as refrigerated trucks, sanitation vehicles, and engineering vehicles), a version with 154 horsepower or above and meeting China V emission standards or above is typically selected to meet load and power requirements.

Why Choose DDP Engine:
100% Quality Guaranteed: All parts undergo rigorous testing to ensure perfect compatibility and premium performance.
Fast Worldwide Shipping: Large inventory in stock. Orders are typically processed within 3-7 working days with reliable global express and Transportation.
Professional Technical Support: Unsure about the part number? Contact our engineering team for exact cross-reference matching.
Flexible Solutions: Providing Genuine, OEM, and premium Aftermarket spare parts to fit your budget.