🔧 Highlander - Timing Chain Service Guidance

Your Highlander’s 2.7L inline-4 engine does not use a timing belt. It uses a timing chain, which is designed to last much longer and usually is not replaced as routine maintenance.

If you are hearing chain rattle, have cam/crank timing codes, poor running, or oil-related chain tensioner issues, this becomes an advanced timing chain repair that requires precise engine timing setup.

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

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⚠️ Safety & Precautions

• ⚠️ Do not attempt to “replace the timing belt” on your Highlander because there is no timing belt to replace.
• ⚠️ Timing chain work can cause severe engine damage if the camshaft or crankshaft timing is set incorrectly.
• ⚠️ Disconnect the negative battery cable before working near the starter, alternator, or engine wiring.
• ⚠️ Support the engine correctly before removing any engine mount parts.
• ⚠️ Never rotate the crankshaft backward unless the service procedure specifically allows it.
• ⚠️ Work only on a cool engine to avoid burns from coolant, oil, and exhaust parts.

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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
• 22mm socket
• 3/8-inch ratchet
• 1/2-inch breaker bar
• 1/2-inch torque wrench
• 3/8-inch torque wrench
• Crankshaft pulley holding tool (specialty)
• Harmonic balancer puller (specialty)
• Engine support bar (specialty)
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum
• Plastic trim clip remover
• Gasket scraper plastic
• Drain pan 10-quart minimum
• Coolant funnel kit
• Feeler gauge set
• 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 - Qty: 1
• Timing chain tensioner - Qty: 1
• Timing chain guide set - Qty: 1
• Timing cover sealant RTV - Qty: 1
• Front crankshaft seal - Qty: 1
• Valve cover gasket set - Qty: 1
• Engine oil filter - Qty: 1
• Engine oil 0W-20 synthetic - Qty: 5 quarts
• Toyota-compatible long-life coolant - Qty: 1 gallon
• Accessory drive 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.
• Disconnect the negative battery cable using a 10mm socket.
• Raise the front of the vehicle with a floor jack rated 3-ton minimum and support it with jack stands rated 3-ton minimum.
• A timing chain is a metal chain inside the engine that keeps the crankshaft and camshafts moving together at the correct time.
• An engine support bar holds the engine from above when a mount must be removed.
• If your Highlander only needs normal maintenance, do not replace the timing chain unless there is a confirmed fault.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm This Is Not a Timing Belt Job

• Open the hood and locate the front of the engine on the passenger side.
• Use a flashlight if needed to inspect the engine front cover area.
• Your Highlander has a sealed metal timing cover, not an external timing belt cover.
• No belt service interval applies.

Step 2: Drain Engine Oil and Coolant

• Place a drain pan 10-quart minimum 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 10-quart minimum under the radiator drain area and drain coolant carefully.
• Use nitrile gloves and safety glasses because coolant is toxic and slippery.

Step 3: Remove Engine Covers and Accessory Belt

• Use a 10mm socket to remove any plastic engine cover fasteners.
• Use a plastic trim clip remover to release splash shield clips under the passenger side.
• Use a 19mm socket on the belt tensioner to relieve belt tension.
• Slide the accessory drive belt off the pulleys and remove it.
• Take a belt routing photo first.

Step 4: Support the Engine

• Install the engine support bar (specialty) across the upper body structure.
• Attach the support chain to the engine lift point.
• Apply light upward tension only. Do not lift the vehicle by the engine.
• A floor jack rated 3-ton minimum with a wood block may be used under the engine oil pan only as light backup support.

Step 5: Remove Passenger-Side Engine Mount Components

• Use a 14mm socket and 17mm socket to remove the passenger-side mount bracket bolts as needed for access.
• Keep bolts organized by location because lengths can vary.
• During reassembly, tighten mount fasteners to the matching Toyota specification for their position. If exact bolt location is uncertain, stop and verify before tightening.

Step 6: Remove the Crankshaft Pulley

• Install the crankshaft pulley holding tool (specialty) to hold the pulley still.
• Use a 22mm socket with a 1/2-inch breaker bar to loosen the crankshaft pulley bolt.
• Use a harmonic balancer puller (specialty) to remove the pulley without prying on it.
• Do not pry against the timing cover because it can crack or bend.

Step 7: Remove Valve Cover and Timing Cover

• Use a 10mm socket to remove ignition coil fasteners and valve cover bolts.
• Lift the valve cover off carefully and remove the old gasket.
• Use a 10mm socket, 12mm socket, and 14mm socket to remove timing cover bolts.
• Use a plastic gasket scraper to separate sealant areas gently.
• Do not gouge the aluminum sealing surfaces.

Step 8: Set Engine to Top Dead Center

• Use a 22mm socket on the crankshaft bolt to rotate the engine clockwise only.
• Align the crankshaft and camshaft timing marks to their service positions.
• Use a paint marker to mark the old chain and sprockets before removal.
• Top Dead Center means piston number 1 is at the top of its compression stroke.
• Correct timing is critical.

Step 9: Remove Timing Chain Tensioner and Guides

• Use a 10mm socket to remove the timing chain tensioner bolts.
• Use a 12mm socket to remove guide bolts as equipped.
• Remove the timing chain guides and keep note of their positions.
• Remove the timing chain from the sprockets without rotating the camshafts or crankshaft.

Step 10: Install New Timing Chain and Guides

• Match the colored timing chain links to the crankshaft and camshaft timing marks.
• Install the new timing chain guides using a 10mm socket or 12mm socket as applicable.
• Install the new timing chain tensioner.
• Use a 3/8-inch torque wrench to tighten small guide and tensioner bolts to Toyota specification for each bolt size.
• Do not guess torque on small aluminum-thread bolts because stripped threads are expensive to repair.

Step 11: Verify Timing Before Closing Engine

• Use a 22mm socket to rotate the crankshaft clockwise by hand two full turns.
• Stop immediately if the engine locks or feels like metal contact.
• Recheck that all timing marks return to the correct alignment.
• Use a feeler gauge set only if checking related clearances during deeper inspection.
• Hand-rotate before starting.

Step 12: Reseal Timing Cover and Reinstall Valve Cover

• Use a plastic gasket scraper and shop towels to clean old sealant from the timing cover and engine block.
• Apply timing cover sealant RTV in the factory bead pattern.
• Install the timing cover and start all bolts by hand.
• Use a 3/8-inch torque wrench to tighten timing cover bolts in stages to Toyota specification by bolt size.
• Install the new valve cover gasket and reinstall the valve cover with a 10mm socket.

Step 13: Reinstall Crankshaft Pulley and Engine Mount

• Install the crankshaft pulley by hand, making sure it seats straight.
• Use the crankshaft pulley holding tool (specialty) and 22mm socket to tighten the crankshaft pulley bolt to Toyota specification.
• Reinstall engine mount brackets using a 14mm socket and 17mm socket.
• Use a 1/2-inch torque wrench to tighten mount fasteners to Toyota specification for their exact bolt position.

Step 14: Reinstall Belt, Fluids, and Battery Cable

• Use a 19mm socket to move the belt tensioner and install the accessory drive belt.
• Install a new engine oil filter and refill with engine oil 0W-20 synthetic.
• Refill the cooling system with Toyota-compatible long-life coolant using a coolant funnel kit.
• Reconnect the negative battery cable using a 10mm socket.
• Torque battery terminal nut to 5 Nm (44 in-lbs).

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✅ After Repair

• Start the engine and let it idle. Listen for rattling, knocking, or chain slap.
• Check for oil leaks around the timing cover, valve cover, oil filter, and drain plug.
• Check for coolant leaks and allow trapped air to bleed from the cooling system.
• Watch the temperature gauge and shut the engine off if it begins to overheat.
• After the first full heat cycle, recheck oil level and coolant level.
• If the check engine light comes on, scan for camshaft/crankshaft correlation codes before driving far.

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💰 DIY vs Shop Cost

Shop Cost: $1,500-$2,800 parts + labor

DIY Cost: $300-$750 parts only

You Save: $1,000-$2,000 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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