🔧 Highlander - Engine Mount Replacement

Replacing engine mounts on your Highlander means supporting the engine safely, removing the worn mount, and installing a new mount without putting stress on the hybrid transaxle, exhaust, wiring, or hoses. Engine mounts hold the engine in place and absorb vibration, so bad mounts can cause clunks, shaking, or excessive engine movement.

Difficulty Level: Advanced | Estimated Time: 2-5 hours depending on mount location

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⚠️ Safety & Precautions

• ⚠️ Your Highlander is a hybrid. Do not touch orange high-voltage cables or high-voltage components.
• ⚠️ Disconnect the 12-volt battery before working near engine wiring or the inverter area.
• ⚠️ Never place any part of your body under an engine supported only by a jack.
• ⚠️ Use a wide wood block between the floor jack and engine oil pan to spread the load. Do not jack directly on the bare oil pan.
• ⚠️ Support the engine only enough to remove mount load. Lifting too high can damage hoses, wiring, exhaust parts, or the hybrid transaxle.
• ⚠️ If removing any mount near the lower subframe, support the vehicle with jack stands on solid ground.

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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
• Ratchet wrench
• Breaker bar 1/2-inch drive
• Torque wrench rated 10-250 Nm
• 3-inch socket extension
• 6-inch socket extension
• Universal joint socket adapter
• 14mm combination wrench
• 17mm combination wrench
• Flat-blade screwdriver medium
• Trim clip removal tool
• Floor jack rated 3-ton minimum
• Jack stands rated 3-ton minimum
• Wheel chocks
• Wood block 2x6-inch minimum
• Work light
• Paint marker
• Safety glasses
• Mechanic gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine mount assembly - Qty: 1 per failed mount
• Engine mounting bolts - Qty: As needed if damaged or corroded
• Engine mounting nuts - Qty: As needed if damaged or corroded
• Underbody splash shield clips - Qty: As needed

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📋 Before You Begin

• Park your Highlander on a level surface.
• Set the parking brake and place wheel chocks behind the rear wheels.
• Open the hood and let the engine cool completely.
• Use a 10mm socket to disconnect the negative terminal from the 12-volt battery.
• Take clear photos of the mount, brackets, bolt positions, wiring clips, and hose routing before removing anything.
• Use a paint marker to mark the original mount position before loosening bolts.
• A breaker bar is a long-handled wrench used to loosen tight bolts with less effort.
• A torque wrench is used to tighten bolts accurately so they are not too loose or too tight.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and Secure the Vehicle if Needed

• Use wheel chocks to block the rear wheels.
• Use a floor jack rated 3-ton minimum to lift the front of your Highlander only if you need lower mount access.
• Place jack stands rated 3-ton minimum under the front support points.
• Gently lower the vehicle onto the jack stands.
• Shake the vehicle lightly by hand to confirm it is stable before working underneath.

Step 2: Remove Lower Splash Shields if Needed

• Use a 10mm socket to remove splash shield bolts.
• Use a trim clip removal tool to remove plastic splash shield clips.
• Use a flat-blade screwdriver medium to release any stubborn clip centers.
• Set the splash shields aside in order.

Step 3: Support the Engine

• Place a wood block 2x6-inch minimum on the floor jack pad.
• Position the floor jack under a strong, flat area of the engine oil pan.
• Raise the jack slowly until the wood block just contacts the oil pan.
• Lift only enough to take weight off the mount. Do not raise the engine more than necessary.
• Tip: Small jack movements are safest.

Step 4: Inspect the Mount and Nearby Parts

• Use a work light to inspect the engine mount rubber for cracks, separation, leaking fluid, or collapsed rubber.
• Use a work light to check nearby hoses, wiring, and brackets before loosening bolts.
• Use a paint marker to mark the mount’s original position on the bracket and body.

Step 5: Remove Components Blocking Access

• Use a 10mm socket to remove small brackets or covers blocking the mount.
• Use a 12mm socket or 14mm socket to remove nearby support brackets if they block access.
• Use a flat-blade screwdriver medium to release wiring harness retainers from brackets, if needed.
• Do not stretch or pull on wiring harnesses.

Step 6: Loosen the Mount Through-Bolt or Center Nut

• Use a 17mm socket, 19mm socket, or 21mm socket with a breaker bar 1/2-inch drive to loosen the main mount fastener.
• Use a 17mm combination wrench to hold the opposite side if the bolt spins.
• Do not fully remove the bolt until the engine is supported and the mount load is relieved.

Step 7: Remove Mount-to-Body and Mount-to-Bracket Bolts

• Use a 14mm socket or 17mm socket with a ratchet wrench to remove the mount-to-body bolts.
• Use a 14mm combination wrench or 17mm combination wrench where a socket will not fit.
• Use a 3-inch socket extension, 6-inch socket extension, or universal joint socket adapter for hard-to-reach bolts.
• Keep each bolt grouped by location so it goes back in the same place.

Step 8: Remove the Old Engine Mount

• Use the floor jack to raise or lower the engine slightly until the mount is free of tension.
• Remove the main through-bolt or center nut by hand once loose.
• Lift the mount out of the engine bay or lower opening by hand.
• If the mount will not slide out, use the floor jack to adjust the engine height a very small amount.
• Do not pry against the hybrid transaxle case, inverter, or aluminum engine covers.

Step 9: Compare the New Mount

• Place the old and new engine mount side by side.
• Confirm the stud locations, bolt holes, bracket shape, and rubber orientation match.
• Confirm any arrows, alignment marks, or locating pins face the same direction as the old mount.

Step 10: Install the New Engine Mount

• Set the new mount into position by hand.
• Use the floor jack to raise or lower the engine slightly until bolt holes line up naturally.
• Install all bolts and nuts by hand first to avoid cross-threading.
• Use a 14mm socket, 17mm socket, 19mm socket, or 21mm socket to snug the fasteners, but do not fully tighten yet.
• Tip: Start every bolt before tightening.

Step 11: Torque the Engine Mount Fasteners

• Use a torque wrench rated 10-250 Nm with the correct socket to tighten smaller mount bracket bolts to Torque to 52 Nm (38 ft-lbs).
• Use a torque wrench rated 10-250 Nm with the correct socket to tighten main mount bolts or nuts to Torque to 95 Nm (70 ft-lbs).
• If your replacement mount instructions give different torque values, use the instructions supplied with the part.
• After torquing, slowly lower the floor jack until the engine weight rests fully on the new mount.

Step 12: Reinstall Removed Brackets and Covers

• Use a 10mm socket, 12mm socket, or 14mm socket to reinstall any brackets or covers removed for access.
• Use a flat-blade screwdriver medium to guide wiring clips back into their original brackets.
• Make sure no wiring, hoses, or clips are trapped under the mount or bracket.

Step 13: Reinstall Lower Splash Shields

• Lift the splash shield into position by hand.
• Use a trim clip removal tool to help align plastic clips if needed.
• Press plastic clips in by hand until seated.
• Use a 10mm socket to reinstall splash shield bolts.

Step 14: Lower the Vehicle and Reconnect Battery

• Use a floor jack rated 3-ton minimum to lift the vehicle slightly off the jack stands.
• Remove the jack stands rated 3-ton minimum.
• Lower your Highlander slowly to the ground.
• Use a 10mm socket to reconnect the negative 12-volt battery cable.
• Tighten the battery terminal snugly. Do not overtighten it.

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✅ After Repair

• ✅ Start your Highlander and let it idle while you watch the engine for abnormal movement.
• ✅ Shift from Park to Reverse and Drive while holding the brake firmly. Listen for clunks.
• ✅ Check that no warning lights remain on after the vehicle is restarted.
• ✅ Test drive gently at low speed first, then recheck for noise or vibration.
• ✅ Recheck accessible mount fasteners after the first drive if the mount instructions recommend it.
• ✅ If vibration is worse after replacement, stop driving and recheck mount orientation and fastener seating.

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💰 DIY vs Shop Cost

Shop Cost: $450-$1,200 per mount (parts + labor)

DIY Cost: $120-$450 per mount (parts only)

You Save: $330-$750 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-4.0 hours depending on mount location.

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🎯 Ready to get started?

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