🔧 Highlander - Timing Component Service

Your Highlander with the 2.7L inline-4 does not use a timing belt. It uses a timing chain, which is internal to the engine and is not a normal maintenance replacement item like a belt.

If you are hearing chain rattle, have cam/crank correlation codes, or have a front engine oil leak, the timing chain system may need diagnosis and repair. This is a major internal engine job.

Difficulty Level: Advanced | Estimated Time: 8-12 hours

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⚠️ Safety & Precautions

• ⚠️ Disconnect the negative battery cable before working near the starter, alternator, or engine wiring.
• ⚠️ Support the engine correctly before removing the right-side engine mount.
• ⚠️ Do not rotate the crankshaft or camshafts independently once the timing chain is removed.
• ⚠️ Incorrect valve timing can cause poor running, no-start, or internal engine damage.
• ⚠️ Engine oil and coolant may spill during this repair; clean spills immediately.
• ⚠️ Let the engine cool fully before opening the cooling system.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 12mm socket
• 14mm socket
• 17mm socket
• 19mm socket
• 21mm socket
• 3/8-inch ratchet
• 1/2-inch breaker bar
• 1/2-inch torque wrench
• 3/8-inch torque wrench
• Serpentine belt tool
• Crankshaft pulley holder (specialty)
• Harmonic balancer puller (specialty)
• Engine support bar (specialty)
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Trim clip removal tool
• Plastic scraper
• Drain pan
• Funnel
• Paint marker
• Shop towels
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Timing chain kit - Qty: 1
• Timing chain tensioner - Qty: 1
• Timing chain guides - Qty: 1 set
• Front timing cover sealant - Qty: 1
• Crankshaft front seal - Qty: 1
• Valve cover gasket - Qty: 1
• Engine oil (0W-20 synthetic) - Qty: 5 quarts
• Oil filter - Qty: 1
• Toyota Super Long Life coolant - Qty: As needed
• Serpentine belt - Qty: 1

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📋 Before You Begin

• Park your Highlander on level ground and let the engine cool completely.
• Set the parking brake and place wheel chocks behind the rear wheels.
• A timing chain is the metal chain that keeps the crankshaft and camshafts synchronized.
• A timing mark is a factory reference mark used to align rotating engine parts correctly.
• Take photos before removing hoses, brackets, and wiring connectors.
• Label bolts by location. Toyota engines often use several similar-looking bolt lengths.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect the Battery

• Use a 10mm socket to loosen the negative battery terminal.
• Move the cable away from the battery so it cannot spring back and touch the post.
• Tip: Negative cable comes off first.

Step 2: Raise and Support the Front

• Use a floor jack to lift the front of your Highlander at the approved front jacking point.
• Place jack stands under the front support points.
• Gently lower the vehicle onto the stands and shake the vehicle lightly to confirm it is stable.

Step 3: Remove Lower Splash Shields

• Use a 10mm socket and trim clip removal tool to remove the lower engine splash shield fasteners.
• Set the splash shields aside in order.

Step 4: Drain Engine Oil and Coolant

• Place a drain pan under the engine oil drain plug.
• Use a 14mm socket to remove the oil drain plug and drain the oil.
• Reinstall the oil drain plug and torque to 40 Nm (30 ft-lbs).
• Move the drain pan under the radiator drain area and drain coolant as needed.
• Use nitrile gloves and safety glasses when handling used fluids.

Step 5: Remove the Serpentine Belt

• Use a serpentine belt tool on the belt tensioner to release belt tension.
• Slide the belt off the pulleys and remove it from the engine bay.
• A tensioner is a spring-loaded pulley that keeps the belt tight.
• Tip: Photograph belt routing first.

Step 6: Support the Engine

• Install an engine support bar across the upper body support area.
• Attach the support chain to the engine lifting point and take up light tension.
• Do not lift the engine high; just support its weight.

Step 7: Remove the Right Engine Mount Area

• Use a 14mm socket and 17mm socket to remove the right-side engine mount bracket fasteners as needed for timing cover access.
• Keep the bolts grouped by bracket location.
• On reassembly, tighten common engine mount fasteners to factory spec if available; do not guess if a bolt location differs.

Step 8: Remove the Crankshaft Pulley

• Install the crankshaft pulley holder to hold the pulley still.
• Use a 19mm socket and 1/2-inch breaker bar to loosen the crankshaft pulley bolt.
• Use a harmonic balancer puller to remove the crankshaft pulley.
• A harmonic balancer is the large crank pulley that also helps reduce engine vibration.

Step 9: Remove Valve Cover

• Use a 10mm socket to remove ignition coil and valve cover fasteners as needed.
• Move wiring gently aside without pulling on the wires.
• Remove the valve cover and old gasket.
• Use a plastic scraper to clean gasket surfaces without scratching aluminum.

Step 10: Set Engine to Top Dead Center

• Use a 19mm socket on the crankshaft bolt area to rotate the engine clockwise only.
• Align the crankshaft and camshaft timing marks to the factory reference positions.
• Use a paint marker to add your own reference marks on the old chain and sprockets before removal.
• Do not rotate the engine counterclockwise.

Step 11: Remove the Front Timing Cover

• Use 10mm socket, 12mm socket, and 14mm socket to remove timing cover bolts.
• Note bolt length and position carefully.
• Use a plastic scraper to gently separate the cover at the sealant seam.
• Do not pry hard on the aluminum sealing surfaces.

Step 12: Remove Chain Tensioner and Guides

• Use a 10mm socket to remove the timing chain tensioner bolts.
• Use a 10mm socket or 12mm socket to remove timing chain guide bolts as equipped.
• Remove the chain guides and timing chain.
• Keep the camshaft sprockets and crankshaft sprocket from moving.

Step 13: Install New Timing Chain

• Match the colored links on the new timing chain to the timing marks on the crankshaft and camshaft sprockets.
• Use your paint marker reference marks as a backup check only.
• Install the new chain guides using a 10mm socket or 12mm socket.
• Install the new tensioner using a 10mm socket.
• Torque small timing guide and tensioner fasteners to the correct Toyota specification for their exact location before final assembly.

Step 14: Verify Timing by Hand

• Use a 19mm socket to rotate the crankshaft clockwise two full turns.
• Stop if you feel hard resistance.
• Recheck that the crankshaft and camshaft timing marks return to their correct positions.
• If the marks do not align, do not start the engine.

Step 15: Reinstall the Timing Cover

• Use a plastic scraper and shop towels to clean old sealant from the engine and cover.
• Apply new front timing cover sealant to the specified sealing path.
• Install the timing cover carefully without smearing the sealant.
• Use 10mm socket, 12mm socket, and 14mm socket to install bolts in their original positions.
• Tighten timing cover bolts evenly; torque depends on bolt size and location.

Step 16: Install Crankshaft Pulley

• Install the crankshaft pulley by hand until seated.
• Use the crankshaft pulley holder to hold the pulley.
• Use a 19mm socket and 1/2-inch torque wrench to tighten the crankshaft pulley bolt to the correct Toyota specification.
• Do not use an impact gun for final tightening.

Step 17: Reinstall Valve Cover

• Install the new valve cover gasket into the valve cover groove.
• Place the valve cover onto the cylinder head.
• Use a 10mm socket to install the fasteners by hand first.
• Tighten gradually in an even pattern; small valve cover fasteners are easy to overtighten.

Step 18: Reinstall Engine Mount and Belt

• Use 14mm socket and 17mm socket to reinstall the right-side engine mount brackets.
• Remove the engine support bar only after all mount fasteners are installed and tightened.
• Use the serpentine belt tool to install the new serpentine belt following the original routing photo.

Step 19: Refill Fluids

• Use a funnel to refill engine oil with 0W-20 synthetic oil.
• Use a funnel to refill coolant with Toyota Super Long Life coolant.
• Check that the oil drain plug and coolant drain are closed before filling.

Step 20: Reconnect Battery and Start Engine

• Use a 10mm socket to reconnect the negative battery terminal.
• Start the engine and let it idle.
• Listen for abnormal rattling, knocking, or chain noise.
• Shut the engine off immediately if it runs rough or makes loud mechanical noise.

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✅ After Repair

• ✅ Check for oil leaks around the timing cover, valve cover, oil filter, and drain plug.
• ✅ Check coolant level after the engine warms up and cools back down.
• ✅ Confirm the serpentine belt tracks straight on every pulley.
• ✅ Clear any stored engine codes with a scan tool if diagnostic codes were present before repair.
• ✅ Road test gently, then recheck oil and coolant levels.

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💰 DIY vs Shop Cost

Shop Cost: $1,800-$3,200 (parts + labor)

DIY Cost: $300-$750 (parts only)

You Save: $1,050-$2,900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 8-12 hours.

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🎯 Ready to get started?

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