🔧 Highlander - Timing Belt Replacement (Not Applicable: Timing Chain Equipped)

Your Highlander’s 3.5L V6 uses a timing chain, not a timing belt. That means there is no scheduled “timing belt replacement” service like on belt-driven engines.

Instead, the timing chain is designed to last the life of the engine when oil changes are kept up. Chain service is only done if there are symptoms or internal engine repairs.

Difficulty Level: Beginner (verification) | Estimated Time: 0.2-0.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns from hot parts.
• ⚠️ Keep fingers, hair, and clothing away from moving belts and fans if the engine is running.
• ⚠️ If you remove any covers near the accessory belt, keep the key/fob away from the vehicle to prevent accidental starting.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• Short 1/4" extension
• Trim clip removal tool
• Flashlight
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• No parts required - Qty: 0
• Engine oil (0W-20 full synthetic) - Qty: 7 quarts
• Oil filter - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Open the hood and let the engine cool fully.
• Have a flashlight ready so you can see labels and cover bolts clearly.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm what your engine uses

• Use a flashlight and look for any under-hood service label or emissions label that references “timing belt.”
• On your Highlander’s V6, you will not find a timing belt interval because it is chain-driven.
• If it says “chain,” there’s no belt service.

Step 2: Identify the belt you can see (this is NOT the timing belt)

• Use a flashlight to look at the belt on the passenger side of the engine bay.
• This visible belt is the serpentine belt (the external belt that runs the alternator/AC). The timing chain is internal and not visible like that.

Step 3: Quick check for timing-chain-related warning signs

• With the engine cold, start it and listen from the front of the engine bay.
• If you hear a loud rattling for more than ~1 second at cold start, that can be a sign of timing chain tensioner wear (the tensioner is a spring/oil-pressure device that keeps the chain tight).
• If you have a check-engine light with cam/crank correlation codes (example: P0016), that can also point toward chain/tensioner/guide wear.

Step 4: Optional—remove the plastic engine cover for a better look around

• Use a 10mm socket, 1/4" drive ratchet, and short 1/4" extension to remove engine cover fasteners (if equipped).
• Use a trim clip removal tool if any plastic clips are present.
• Lift the cover off and set it aside.

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✅ After Repair

• Reinstall the engine cover using the 10mm socket and 1/4" drive ratchet (snug only; do not over-tighten).
• If your goal was “timing belt maintenance,” the correct maintenance on your Highlander is regular oil changes using 0W-20 to protect the chain and tensioner.
• If you noticed persistent rattling at startup or have a check-engine light, chain system diagnosis is the next step (this is usually not a beginner DIY job).

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💰 DIY vs Shop Cost

Shop Cost: $0-$0 (no timing belt service on this engine)

DIY Cost: $0-$0 (verification only)

You Save: $0-$0 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This verification takes a shop approximately 0.2-0.5 hours.

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🎯 Ready to get started?

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