Parts for your 2006 Subaru Forester-Ignition coils

2006 Subaru Forester ignition coils: what they do and when to service them

Technical sources confirm ignition coils are used on the 2006 Subaru Forester. The 2006MY Subaru Forester Factory Service Manual (Engine – Ignition System) details a four-tower coil pack and leads on the non‑turbo EJ253, and individual coil‑on‑plug units on the turbo EJ255 (Forester XT). Subaru’s FAST electronic parts catalogue lists ignition coil components for both variants, and common workshop references (e.g., Haynes manual for 2003–2008 Forester) include testing and replacement procedures. So ignition coils are absolutely relevant on this model.

This Forester relies on its ignition coils to turn the 12‑volt battery feed into the high voltage needed to fire the spark plugs and light off the fuel–air mix. On the 2.5X (EJ253), a single coil pack fires pairs of cylinders in a wasted‑spark set‑up via high‑tension leads. On the Forester XT (EJ255), each cylinder gets its own coil‑on‑plug pencil coil for crisp spark control under boost. Either way, healthy coils are key to smooth running, decent fuel economy, and clean emissions.

Coils aren’t a routine “every X kilometres” replacement, but they do age from heat, vibration, and moisture. As part of regular servicing—especially when doing spark plugs—it’s smart to inspect and test them. Typical red flags include:

• Rough idle, hesitation, poor power, or hard starting
• Increased fuel use and a whiff of raw petrol from the exhaust
• Check Engine Light with misfire codes (P0301–P0304) or coil circuit codes (P0351–P0354)
• Cracks, carbon tracking, or heat discolouration on the coil or boots, perished plug leads on non‑turbo models

Service tips that workshop pros in AU/NZ lean on:

• Check coil primary/secondary resistance against FSM specs, use an oscilloscope if available for coil‑on‑plug waveforms
• On EJ253, replace tired leads with quality items and apply dielectric grease inside boots to keep moisture out
• On EJ255, inspect the pencil‑coil boots for oil contamination from cam cover leaks—clean or replace as needed
• Keep plug gaps to spec, wide gaps stress coils. Use the correct heat range plugs for local fuel and climate

When replacement is due, go OEM or trusted aftermarket coils—cheapies can create chasing‑your‑tail misfires. The EJ253 coil pack is replaced as a unit, the EJ255’s coils can be swapped cylinder by cylinder, but if one fails late in life, checking the others is sensible. Disconnect the battery, work on a cool engine, secure all connectors, and follow torque specs from the FSM. Clear any codes, take a decent test drive, and recheck for stored faults. That’s the sort of tidy work that keeps a 2006 Forester happy for many more kilometres under the bonnet.

Popular questions about 2006 Subaru Forester ignition coils

Do all 2006 Foresters use the same type of ignition coil?

No. The non‑turbo 2.5X (EJ253) uses a single four‑tower coil pack with spark plug leads. The turbo Forester XT (EJ255) runs individual coil‑on‑plug units at each cylinder. Servicing steps overlap, but parts and testing methods differ.

How long do the ignition coils typically last?

There’s no fixed interval. Many coils run beyond 150,000–250,000 kilometres, but heat and age can bring earlier failures. Treat coils as “inspect and replace when faulty,” and always verify plugs, gaps, and leads/boots so the coil isn’t masking another issue.

Is it safe to drive with a misfiring coil?

Best avoided. A misfire can overheat the catalytic converter with unburnt fuel and may foul plugs. If the Check Engine Light is flashing or the car’s running rough, reduce driving and sort the fault promptly to avoid extra cost.