Belts and pulleys
Most engines use one serpentine belt to drive the alternator, water pump, power steering pump, and A/C compressor. An automatic tensioner keeps it tight, and idler pulleys guide it. A timing belt, where an engine has one, keeps the crankshaft and camshafts in step and is usually replaced on a set schedule.
Common parts
- 1Serpentine and V-ribbed belts
- 2V-belts on older vehicles
- 3Timing belts and timing belt kits with water pumps
- 4Belt tensioners and tensioner pulleys
- 5Idler pulleys
- 6Crankshaft pulleys and harmonic balancers
Finding the right fit
Belts are sized by rib count and length. The routing often changes with options such as A/C, so a diagram on a label under the hood helps. Timing belt kits vary by engine, and some include the water pump because it is driven by the same belt.
Hoses and clamps
Hoses connect the engine to the radiator and heater, and carry vacuum, fuel vapor, and crankcase gases. Many are molded to a specific shape.
Common parts
| Ref | Part group |
|---|---|
| BH-01 | Upper and lower radiator hoses |
| BH-02 | Heater hoses |
| BH-03 | Bypass and coolant pipes |
| BH-04 | Vacuum and PCV hoses |
| BH-05 | Power steering hoses |
| BH-06 | Hose clamps and quick-connect fittings |
Signs of trouble
A hose that feels soft, swollen, or crunchy when the engine is cool is due for replacement. Look for cracks near the clamps and white or green crust from dried coolant. A hissing at idle can come from a cracked vacuum hose, which can also set a lean code.
Finding the right fit
Molded hoses are matched to the engine and sometimes to the radiator style. Universal hoses can work in a pinch but may kink. Use the clamp type the vehicle was built with, or one rated for the job.
Fitment checklist
- Count the belt ribs and read the length printed on the old belt
- Photograph the routing or find the diagram label under the hood
- Check whether the engine has a timing belt or a timing chain
- On a timing belt job, decide whether to replace the water pump and idlers at the same time
- Squeeze each coolant hose on a cool engine; replace soft, swollen, or cracked ones
- Match the clamp type to the one the vehicle came with
Before you order
Start with the year, make, model, and engine, then narrow it down with the trim, drive type, and any option the part depends on. The VIN is the most reliable way to do that, because many parts catalogs and dealer counters decode it to the exact build. If the old part is in hand, its original-equipment number is the best cross-reference. Aftermarket brands publish their own numbers and usually list the original number they replace. Two listings that both say they fit can still differ, so compare the photos, connectors, mounting points, and the notes in the listing. The find the right part guide covers this step, and the all makes reference lists each maker’s official parts catalog.
Once you know the part number, compare the same number across stores. Look past the first price at the core charge, shipping, the return window, and what the warranty covers and who honors it. A remanufactured part, a new aftermarket part, and an original-equipment part can each be the right choice, but they are not the same purchase. The compare prices and warranties guide walks through what to read. Prices on PartIndex carry the date they were recorded, so confirm the current price and fitment with the retailer before you buy.