Parts for your 2007 Toyota Highlander-Spark plugs

2007 Toyota Highlander (Kluger): Spark Plugs, Purpose and Servicing Advice

Yes, the 2007 Toyota Highlander (known as Kluger in Australia and New Zealand) uses spark plugs. This is confirmed by Toyota’s 2007 Highlander Repair Manual and Scheduled Maintenance Guide, and by Denso and NGK catalogues for the 2.4‑litre 2AZ‑FE and 3.3‑litre 3MZ‑FE petrol engines. Both engines use coil‑on‑plug ignition with long‑life iridium plugs.

Spark plugs do the crucial job of igniting the air–fuel mix in each cylinder. With a strong, consistent spark, the Highlander starts crisply, runs smoothly, sips less petrol, and keeps emissions in check. On these engines, Toyota specifies iridium plugs because they hold their sharp edge and stable gap for far longer than copper types, which is why the service interval is extended.

For most 2007 Highlanders/Klugers, the correct plugs are iridium, gapped to about 1.1 mm, with OEM‑equivalent Denso or NGK part numbers depending on engine variant. Always match by engine code and confirm in the owner’s manual or dealer parts system. Typical tightening torque is around 18 N·m, over‑torquing can damage threads, and under‑torquing can affect heat transfer.

Replacement timing: Toyota’s guidance for the iridium plugs is up to 160,000–192,000 km under normal use. Shorter intervals make sense if the vehicle tows, idles a lot, or mainly does short trips. Clues it’s time to replace include rough idle, sluggish acceleration, misfire under load, harder cold starts, poorer fuel economy, or a check‑engine light with misfire codes.

• Use quality iridium plugs and keep the gap at 1.1 mm if pre‑set.
• Do not use anti‑seize on new Denso/NGK plugs, it alters torque. Fit them to a cool engine.
• Add a tiny smear of dielectric grease inside each coil boot to ease future removal and prevent tracking.
• Blow debris from plug wells before removal, and torque to spec.
• I4 2.4L is straightforward for DIY. V6 3.3L has a tight rear bank and may require upper intake removal—many owners prefer a technician for that job.

Staying on top of spark plug health keeps this Highlander/Kluger feeling lively and efficient, and helps protect the catalytic converters by preventing long‑term misfires.

FAQs

What spark plug type and gap suit a 2007 Toyota Highlander/Kluger?
These engines take long‑life iridium plugs (OEM‑equivalent Denso or NGK) with a 1.1 mm gap. Part numbers vary by engine code (2AZ‑FE vs 3MZ‑FE), so it’s best to match by VIN or engine label and follow Toyota’s specification. Torque to about 18 N·m on a cool engine and avoid anti‑seize on new plugs.

How often should the plugs be replaced?
Toyota’s schedule for the 2007 model year allows up to 160,000–192,000 km for iridium plugs in normal use. Replace earlier if there are symptoms like rough idle, hesitation, reduced fuel economy, or misfire codes, or if the vehicle tows, idles for long periods, or mostly does short, cold runs.

Can a home mechanic change them?
The 2.4L I4 is quite DIY‑friendly with basic tools, a torque wrench, and care under the bonnet. The 3.3L V6’s rear bank is much tighter and may require removing the upper intake manifold, many owners choose a professional for that job to save time and avoid air leaks.