🔧 IS - Timing Belt Replacement

Your IS does not use a timing belt. It uses a timing chain, which is designed to last much longer and usually isn’t a scheduled maintenance item.

If you’re chasing a rattle, check-engine light, or cam/crank timing codes, the job becomes a timing chain service (chain/tensioner/guides). This is a big, precision job and mistakes can cause severe engine damage.

Difficulty Level: Advanced | Estimated Time: 8-14 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cold engine; hot coolant and turbo components can burn.
• ⚠️ Support the vehicle with jack stands; never rely on a jack.
• ⚠️ Disconnect the negative battery terminal before starting.
• ⚠️ Keep fingers clear when rotating the crankshaft; pinch hazard.
• ⚠️ If timing is set wrong, the engine can be damaged on startup.
• ⚠️ RTV sealant and solvents need ventilation; avoid skin/eye contact.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Drain pan (at least 10-quart)
• Shop towels
• Metric socket set (8mm-22mm)
• 1/4" drive ratchet
• 3/8" drive ratchet
• 1/2" drive breaker bar
• Torque wrench (10-80 ft-lbs)
• Torque wrench (50-250 ft-lbs)
• Metric combination wrench set (8mm-22mm)
• Allen key set (metric)
• Trim clip remover tool
• Flathead screwdriver
• Phillips screwdriver
• Pry bar (small)
• Harmonic balancer/crank pulley puller kit (specialty)
• Crank pulley holding tool (specialty)
• Engine support bar (specialty)
• RTV gasket scraper (plastic)
• Brake cleaner spray
• Paint marker
• Funnel

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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, OEM-style) - Qty: 1
• Front crankshaft seal - Qty: 1
• Accessory drive belt - Qty: 1
• Engine oil (0W-20 full synthetic) - Qty: 6 quarts
• Oil filter - Qty: 1
• Engine coolant (Toyota/Lexus pink, prediluted) - Qty: 2 gallons
• Replacement plastic clips (splash shield/liner) - Qty: 1 set

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Disconnect the battery using a 10mm socket on the negative terminal.
• Raise the front and support with jack stands at the pinch welds or approved lift points.
• Remove the lower splash shield using a trim clip remover tool and 10mm socket.
• Take photos as you disassemble.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Drain fluids (as needed for timing cover removal)

• Place a drain pan under the radiator drain.
• Open the drain and drain coolant.
• Drain engine oil if the timing cover area will be opened (helps reduce mess).

Step 2: Remove intake ducting and access covers

• Remove the engine cover by pulling upward (it is press-fit).
• Loosen clamps with a flathead screwdriver and remove intake ducting for working room.

Step 3: Support the engine

• Install an engine support bar (specialty) across the strut towers and take the engine’s weight.
• This prevents engine drop when mounts come off.

Step 4: Remove the accessory drive belt

• Relieve belt tension using the correct socket on the belt tensioner (use your metric socket set and ratchet).
• Slip the belt off and inspect it; replace if cracked or glazed.

Step 5: Remove right-side mounting/brackets (as required for cover access)

• Remove the right-front wheel using a 21mm socket (common lug size) and remove the right inner fender liner with a trim clip remover tool.
• Remove necessary engine mount/bracket fasteners using a metric socket set and breaker bar.
• Torque to OEM specification during reassembly (mount fastener torque is critical and model-specific).

Step 6: Remove the crank pulley (harmonic balancer)

• Install a crank pulley holding tool (specialty) to keep the crank from turning.
• Remove the crank bolt using a breaker bar and appropriate socket from your metric socket set.
• Use a harmonic balancer/crank pulley puller kit (specialty) to pull the pulley off straight.
• Torque to OEM specification when reinstalling the crank bolt (this is very high torque and must be exact).

Step 7: Remove the front timing cover

• Remove all timing cover bolts using a metric socket set and ratchet.
• Carefully break the RTV seal using a plastic RTV gasket scraper and a small pry bar only at cast pry points.
• Clean sealing surfaces using brake cleaner spray and shop towels.
• Do not gouge aluminum surfaces.

Step 8: Set cylinder #1 to TDC on compression

• Rotate the crankshaft by hand using a socket and 1/2" drive ratchet until timing marks align.
• Use a paint marker to mark chain and sprocket alignment points before disassembly.
• Only rotate clockwise unless OEM says otherwise.

Step 9: Remove tensioner and guides

• Remove the timing chain tensioner bolts using a metric socket set.
• Remove the chain guides using a metric socket set.
• Torque to OEM specification on tensioner/guide fasteners during install (small bolts can strip easily).
• Timing chain tensioner: it’s a spring/oil-pressure device that keeps the chain tight.

Step 10: Remove and install the timing chain

• Remove the chain from sprockets carefully, keeping track of timing positions.
• Install the new chain aligning the chain’s colored links (if present) to the sprocket timing marks.
• Reinstall new guides and tensioner using your metric socket set and torque wrench.
• Torque to OEM specification for all timing components.

Step 11: Verify timing before sealing

• Rotate the engine by hand two full revolutions using a socket and 1/2" drive ratchet.
• Re-check timing marks alignment.
• If anything is off, stop and correct it before proceeding.

Step 12: Replace the front crank seal and reseal the timing cover

• Remove the old crank seal carefully with a seal puller from your puller kit (or a careful pry with a small tool), avoiding crank surface damage.
• Install the new seal squarely using an appropriate driver from the puller/installer kit or a suitable large socket.
• Apply timing cover sealant (RTV) as a continuous bead per the sealant instructions.
• Install the timing cover and hand-start all bolts, then tighten evenly using a torque wrench.
• Torque to OEM specification for timing cover bolts (overtightening can crack the cover).

Step 13: Reinstall crank pulley, mounts, and belt

• Reinstall the crank pulley and crank bolt using the crank pulley holding tool (specialty) and torque wrench.
• Torque to OEM specification for the crank bolt (critical).
• Reinstall engine mount/brackets using a metric socket set and torque wrench, then remove the engine support bar.
• Install the accessory belt using a ratchet to move the tensioner.

Step 14: Refill fluids

• Refill engine oil using a funnel; replace the oil filter.
• Refill coolant using a funnel.
• Bleed air from the cooling system per OEM procedure (air pockets can cause overheating).

Step 15: Reconnect battery and initial start

• Reconnect the battery negative terminal using a 10mm socket.
• Start the engine and listen for abnormal rattles.
• Check for oil/coolant leaks around the timing cover and crank seal area.

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✅ After Repair

• Let the engine reach operating temperature and confirm the radiator fans cycle normally.
• Recheck coolant level after a full cool-down and top off if needed.
• Inspect for leaks again after a short test drive.
• If the check engine light is on, scan for codes before driving further.
• Recheck oil level on level ground.

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💰 DIY vs Shop Cost

Shop Cost: $1,800-$3,500 (parts + labor)

DIY Cost: $350-$900 (parts only)

You Save: $1,450-$2,600 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 8-14 hours.

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🎯 Ready to get started?

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