Parts for your 2010 Subaru Forester-Drive belt tensioner

2010 Subaru Forester drive-belt tensioner — is it actually used?

Short answer: on most 2010 Subaru Forester petrol models sold in Australia and New Zealand (the 2.5-litre EJ25), a separate spring-loaded drive-belt tensioner isn’t fitted. These engines run two accessory belts: the alternator/power-steering belt is tensioned by moving the alternator on its bracket with an adjuster screw, and the A/C belt is either a stretch-fit belt or tensioned with a simple manual idler, not an automatic tensioner assembly.

That means a catalogue “drive-belt tensioner” unit isn’t relevant to the common EJ25-powered 2010 Forester. Ordering a tensioner for these petrol variants will usually result in a part that doesn’t install, because the system relies on bracket adjustment and/or a manual idler rather than a spring-loaded arm.

There is an exception. The 2010 Forester 2.0D (EE20 diesel), offered in ANZ markets, uses a single serpentine belt with an automatic accessory belt tensioner. If the vehicle is the diesel, a drive-belt tensioner absolutely applies. So the need for a tensioner on a 2010 Forester hinges on engine type: petrol EJ25 = no separate auto tensioner