How to Change Spark Plugs in Your Subaru
When I first got my Subaru Outback Wagon, I was at a loss as to where the spark plugs were on this "boxer" type engine. Without any manuals or mention in the Subaru owners guide, I thought I'd better let the Subaru mechanic do it because of some special tool. So, that cost me a good $100 for their time and plugs.
In actuality, the process is easy and any DIY mechanic can do it and save the money. The only problem is that the limited space and access to them on both sides of the engine may cause frustration. You may think spending the money is worth it.
The following is for most Subaru engines, but there may be differences on your Subaru. The spark plugs and wires are nearly invisible when compared to other cars. On the Subaru, the plug is actually beneath a protective square cap held on by an adjacent bolt. You should be using a long extension rod attached to a rachet and a swivel knuckle to allow you to angle the plug remover tool. Removing and replacing is an act of being careful due to lack of space.
1. 2.5 L NON-TURBO MODEL
1) Remove the intake duct and intake chamber.
2) Remove the battery.
3) Disconnect the spark plug cord.
4) Remove the spark plug with a spark plug socket.
5) Tighten the new spark plug lightly with hand, and then secure with a spark plug socket to the specified torque.
Recommended spark plug: NGK: PFR5B-11
Tightening torque: 21 N⋅m (2.1 kgf-m, 15.2 ft-lb)
NOTE:
• Be sure to place the gasket between the cylinder head and spark plug.
• If the torque wrench is not available, tighten the spark plug until gasket contacts cylinder head; then tighten further 1/4 to 1/2 turns.
2. 2.5 L TURBO AND 3.0 L MODEL
1) Remove the battery and battery carrier.
2) Remove the air cleaner case.
3) Detach the connector from ignition coil.
4) Remove the ignition coil.
• 2.5 L Turbo model and 3.0 non-Turbo
Recommended spark plug: NGK: ILFR6B
Tightening torque: 21 N⋅m (2.1 kgf-m, 15.2 ft-lb)
Most of the steps above provide more space and easier access, if you are able to change the plugs without the steps, great.