Parts for your 2010 Subaru Impreza-Drive belt pulley

2010 Subaru Impreza drive-belt pulley — what it does and how to look after it

Based on the Subaru Service Manual for MY2010 Impreza (GE/GH/GR) V-belt section, the Subaru FAST parts catalogue, and aftermarket belt routing guides (e.g., Gates and Dayco) for EJ253/EJ255/EJ257 engines, the 2010 Subaru Impreza uses multiple accessory drive-belt pulleys. These include the crankshaft (harmonic) pulley, alternator pulley, power-steering pump pulley, A/C compressor pulley, plus idler and tensioner pulleys. So yes — a drive-belt pulley absolutely applies to this vehicle.

On the 2010 Impreza, the drive-belt pulleys transfer rotation from the crankshaft to the alternator, power steering, and air-con. The crank pulley also doubles as a harmonic damper, taming torsional vibration to keep the flat-four smooth and to protect the belt system. Many Aussie and Kiwi-delivered EJ engines of this era run two V-ribbed belts (one typically for alternator/power steering and a separate one for the A/C), though exact routing varies slightly between naturally aspirated and turbo models.

When these pulleys are healthy, the belts track straight, accessories charge and pump properly, and there’s no squeal on a cold start. When they’re tired, you’ll hear chirps or grinding, spot belt dust around the front of the engine, or notice the belt “walking” on the edge of a pulley. A failing idler or tensioner bearing can seize or wobble, and a perished rubber layer on the crank pulley/damper can cause misalignment.

As part of regular servicing, the pulleys and belts should be inspected at each service interval. Look and listen for:

• Noise: chirp, whine, or rumble from a pulley bearing
• Play or wobble when the belt is off
• Cracks or separation in the crank pulley’s rubber damper
• Belt glazing, fraying, or tracking marks on pulley faces

Replacement is straightforward for a competent home mechanic, but it’s wise to follow the Subaru workshop procedure. Disconnect the battery, note the belt routing, and spin each pulley by hand with the belt removed to check for roughness. Some variants use a stretch-fit A/C belt that needs the proper installation tool, others use an adjuster screw. Always use quality pulleys and belts, align the belt correctly in the grooves, and tighten to Subaru’s specified torque values. After fitting, run the engine, recheck alignment, and listen under the bonnet for any odd noises. Done right, fresh pulleys and belts will keep the Impreza’s electrics charging, steering light, and cabin nice and cool for many more kilometres.

Popular questions about 2010 Subaru Impreza drive-belt pulleys

Which pulleys are on a 2010 Impreza?

Expect a crankshaft (harmonic) pulley, alternator pulley, power-steering pump pulley, A/C compressor pulley, and one or more idler/tensioner pulleys. Exact layout differs a touch between NA and turbo models, but the roles are the same.

How often should pulleys be replaced?

There’s no fixed kilometre interval for pulleys — they’re changed on condition. Replace any pulley that’s noisy, rough, loose, or leaking grease. Belts are commonly renewed around 60,000–100,000 km or sooner if worn, pulleys are assessed at the same time.

What symptoms point to a bad pulley?

Cold-start squeal, persistent chirp, rumbling or grinding, visible wobble, belt dust, or the belt walking off-centre. If the crank pulley’s rubber damper is cracking or separating, replace it promptly to avoid belt misalignment or accessory damage.