🔧 Sonata - Engine Mount Replacement

This procedure replaces the four main powertrain supports on your Sonata: the passenger-side engine mount, driver-side transmission mount, front roll-stop mount, and rear roll-stop mount. Replace one mount at a time while supporting the engine and transmission so the powertrain cannot shift.

Difficulty Level: Advanced | Estimated Time: 5-8 hours

Assumption: This procedure covers replacement of all four mounts on a stock U.S.-market 2.4L Sonata.

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⚠️ Safety & Precautions

• Never work beneath a vehicle supported only by a floor jack. Use properly rated jack stands.
• Use an engine support bar from above. A support bar spans the fenders and holds the engine with an adjustable chain.
• Do not place a jack directly against the aluminum oil pan. If temporary lower support is necessary, use a wide wood block and only light pressure.
• Remove only one mount at a time. Removing multiple mounts can allow the engine and transmission to move suddenly.
• Disconnect the negative battery cable before removing the battery tray or transmission mount.
• Wear safety glasses and mechanic’s gloves. Mount brackets are heavy and can pinch fingers.
• Allow the exhaust system and engine to cool completely before working near the rear mount.

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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
• 14mm combination wrench
• 17mm combination wrench
• 19mm combination wrench
• 3/8-inch drive ratchet
• 1/2-inch drive breaker bar
• 3/8-inch drive 6-inch extension
• 1/2-inch drive 10-inch extension
• Torque wrench rated 10-150 ft-lbs
• Engine support bar rated 1,000-lb minimum (specialty)
• Hydraulic floor jack rated 2-ton minimum
• Jack stands rated 2-ton minimum
• Wheel chocks
• 12-inch by 12-inch wood block
• Trim-clip removal tool
• Flat-blade screwdriver
• Needle-nose pliers
• Paint marker
• Mechanic’s gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Passenger-side engine mount - Qty: 1
• Driver-side transmission mount - Qty: 1
• Front roll-stop mount - Qty: 1
• Rear roll-stop mount - Qty: 1
• Engine-mount self-locking nuts and bolts - Qty: 1 complete set
• Transmission-mount self-locking nuts and bolts - Qty: 1 complete set
• Roll-stop self-locking bolts - Qty: 1 complete set

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📋 Before You Begin

• Park your Sonata on level, solid ground. Shift into Park, apply the parking brake, and chock both rear wheels.
• Open the hood and allow the engine and exhaust to cool.
• Use a 10mm socket to loosen the negative battery-terminal nut. Disconnect and isolate the negative cable.
• Install the engine support bar across the reinforced inner-fender areas. Attach its chain to the factory engine lifting eye and remove slack without lifting the vehicle.
• Use a paint marker to trace each mount’s original position before loosening it. This helps preserve powertrain alignment.
• Keep each mount’s hardware separate. Several bolts look similar but may have different lengths.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and secure the front of the vehicle

• Use the hydraulic floor jack at the front-center lifting point to raise your Sonata.
• Place the jack stands beneath the reinforced side support points and lower the vehicle onto them.
• Gently shake the vehicle to confirm it is stable before going underneath.
• Use a trim-clip removal tool and 10mm socket to remove the lower engine splash shield.

Step 2: Remove the intake assembly

• Use a flat-blade screwdriver to loosen the air-intake hose clamp at the air-filter housing.
• Use needle-nose pliers to release any attached hose clamp, then disconnect the hose without pulling on its wiring.
• Use a 10mm socket to remove the air-filter housing fasteners.
• Lift the air-filter housing and intake duct from the engine compartment.
• Cover the open intake to keep debris out.

Step 3: Remove the battery and battery tray

• Verify that the negative cable is already disconnected.
• Use a 10mm socket to disconnect the positive terminal. Keep the wrench away from grounded metal.
• Use a 12mm socket to remove the battery hold-down bracket, then lift the battery straight upward.
• Use a 12mm socket and extension to remove the battery-tray bolts.
• Release the attached wiring retainers with the trim-clip removal tool and remove the tray.

Step 4: Replace the passenger-side engine mount

• Confirm that the engine support bar chain is tight enough to carry the engine’s weight without raising it.
• Use a 17mm socket and breaker bar to loosen the mount-to-engine bracket fasteners.
• Use a 14mm or 17mm socket, as fitted, to remove the mount-to-body fasteners.
• Adjust the engine support bar only a few millimeters if a bolt binds. Never force a loaded bolt out.
• Remove the old mount and place the new mount in the same orientation.
• Install every fastener by hand before tightening anything.
• Use the torque wrench to tighten the engine-side fasteners to 59-74 Nm (44-55 ft-lbs).
• Use the torque wrench to tighten the body-side fasteners to 65-80 Nm (48-59 ft-lbs).
• Remove support-bar tension gradually and verify that the mount settles without twisting.

Step 5: Replace the driver-side transmission mount

• Use the engine support bar to support the transmission side of the powertrain. Reposition the chain only at a factory lifting point.
• Use a 17mm socket and breaker bar to loosen the transmission-mount fasteners exposed beneath the battery tray.
• Use a 14mm or 17mm socket, as fitted, to remove the mount-to-body fasteners.
• Adjust the support bar slightly until the bolts slide out without binding.
• Remove the mount and compare its locating tabs and orientation with the replacement.
• Set the new mount over the locating points and start all fasteners by hand.
• Use the torque wrench to tighten the transmission-side fasteners to 50-64 Nm (37-47 ft-lbs).
• Use the torque wrench to tighten the body-side fasteners to 65-80 Nm (48-59 ft-lbs).
• Do not pull misaligned holes together with bolts.

Step 6: Replace the front roll-stop mount

• The roll-stop mount limits forward and backward engine movement during acceleration and braking.
• From beneath the front of your Sonata, locate the mount between the powertrain bracket and front subframe.
• Use a 17mm or 19mm socket and breaker bar to loosen the through-bolt and mounting bolts.
• Use the engine support bar to move the powertrain only enough to unload the through-bolt.
• Remove the old mount and install the replacement with its locating tabs in the original direction.
• Start the through-bolt and mounting bolts by hand.
• Use the torque wrench to tighten the mount-to-subframe fasteners to 88-108 Nm (65-80 ft-lbs).
• Use the torque wrench to tighten the through-bolt to 108-128 Nm (80-94 ft-lbs).

Step 7: Replace the rear roll-stop mount

• Work only after the exhaust has cooled. The rear mount sits close to hot exhaust components.
• Use a 17mm or 19mm socket, extension, and breaker bar to loosen the rear mount through-bolt and bracket bolts.
• If the bolt binds, use the engine support bar to move the powertrain slightly. Do not pry against the exhaust or aluminum transmission case.
• Remove the old mount and install the new mount in the same orientation.
• Start all fasteners by hand to prevent cross-threading.
• Use the torque wrench to tighten the mount-to-subframe fasteners to 88-108 Nm (65-80 ft-lbs).
• Use the torque wrench to tighten the through-bolt to 108-128 Nm (80-94 ft-lbs).

Step 8: Verify powertrain alignment

• Use the paint-marker outlines to confirm that the mounts sit in their original positions.
• Check that no hose, wiring harness, intake tube, or exhaust part is stretched or trapped.
• Use the torque wrench to recheck every accessible mount fastener at its specified torque.
• Gradually release and remove the engine support bar.

Step 9: Reinstall the battery tray and intake

• Position the battery tray and use a 12mm socket to install its bolts. Tighten them securely without crushing the plastic tray.
• Install the battery and use a 12mm socket to secure its hold-down bracket.
• Use a 10mm socket to connect the positive terminal first.
• Reinstall the air-filter housing and use a 10mm socket to secure its fasteners.
• Reconnect the intake hose and use a flat-blade screwdriver to tighten its clamp.
• Use a 10mm socket to connect the negative battery terminal last.

Step 10: Reinstall the splash shield and lower the vehicle

• Use the trim-clip removal tool and 10mm socket to reinstall the lower splash shield and all retainers.
• Use the hydraulic floor jack to raise the vehicle slightly, remove both jack stands, and lower your Sonata slowly.
• Remove the rear wheel chocks only after the vehicle is fully on the ground.

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✅ After Repair

• With the hood open and parking brake applied, start the engine and listen for knocking, rubbing, or abnormal vibration.
• Hold the brake pedal firmly and shift slowly through Reverse, Neutral, and Drive. The engine should move slightly but should not jump or clunk.
• Turn the engine off immediately if a mount twists, a hose stretches, or metal contacts the body.
• Expect the clock and saved radio settings to require resetting after the battery disconnect.
• Take a short, low-speed test drive. Check for vibration at idle, clunks during acceleration, and contact over bumps.
• After the test drive, inspect all four mounts and verify that no fastener has shifted.

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💰 DIY vs Shop Cost

Shop Cost: $1,100-$1,900 (parts + labor)

DIY Cost: $350-$750 (parts only)

You Save: $750-$1,150 by doing it yourself!

Shop labor rates vary by location. This repair takes a shop approximately 4-6 hours.

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🎯 Ready to get started?

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