Parts for your 2009 Subaru Impreza-Drive belt tensioner

2009 Subaru Impreza drive-belt tensioner — is it used?

For the 2009 Subaru Impreza range (EJ-series engines: 2.0/2.5 non‑turbo and WRX/STI turbo), a separate spring‑loaded accessory drive‑belt tensioner is not fitted. Subaru’s factory documentation shows the accessory belts are tensioned either by a manual adjuster on the alternator bracket (alternator/power steering belt) or by a stretch‑fit A/C belt that runs without a tensioner.

Technical references backing this up include the Subaru Service Manual for MY2009 Impreza (Engine – Drive Belt sections for H4 SOHC and H4 Turbo), which specifies belt adjustment via the alternator pivot and jack screw, plus installation procedures for the stretch A/C belt using a special tool. The Subaru parts catalogue for the same model year lists belts, idler pulleys and brackets, but no spring‑loaded accessory belt tensioner assembly. Later FB‑series engines (introduced after this model year) moved to a single serpentine belt with an automatic tensioner, which can cause confusion when cross‑referencing parts.

Why no tensioner on this model? The EJ accessory layout uses two shorter V‑ribbed belts. Tension on the alternator/PS belt is set mechanically at service time, and the A/C belt is designed to maintain correct tension by virtue of its stretch profile. This keeps the setup compact under the bonnet, reduces parts count and cost, and has proven reliable when belts are adjusted or replaced correctly.

What should owners and workshops do instead?

• Inspect both belts at regular service intervals (around every 20,000 km): look for cracking, glazing, fraying, or squeal on cold start.
• Adjust the alternator/PS belt using the jack screw on the alternator bracket, lock the pivot and slider bolts to spec after setting tension.
• Replace the A/C stretch belt rather than attempting to “retension” it. Use the correct installation tool to avoid damaging the belt or pulleys.
• If there’s chirping or slippage after rain, check belt condition, pulley alignment and the alternator bracket hardware before assuming a missing “tensioner”.

Referenced technical sources: Subaru Service Manual (MY2009 Impreza, Engine/Drive Belt procedures – H4 SOHC and H4 Turbo), Subaru genuine parts catalogue (Accessory Drive – Alternator & A/C belts, idlers, brackets), and Subaru Technical Information System service publications for EJ accessory drive layouts.

Popular questions

Does a 2009 Subaru Impreza have a drive‑belt tensioner?
No. It uses a manual adjuster on the alternator for the alternator/power‑steering belt and a stretch‑fit A/C belt with no tensioner. If someone is searching for a spring‑loaded tensioner on this model, they won’t find one under the bonnet.

How are the belts adjusted or replaced on a 2009 Impreza?
Set the alternator/PS belt tension using the alternator jack screw, then tighten the pivot and lock bolts. The A/C belt is replaced, not adjusted, it’s a stretch belt that needs the correct installation tool. Always follow torque specs and steps from the Subaru service manual.

When should the accessory belts be replaced?
Typically at 80,000–100,000 km, or sooner if there are cracks, glazing, squeals or visible damage. Conditions, climate and accessory load can shorten that interval, so regular inspections at service time are a good idea across Australia and New Zealand.