🔧 Sonata - Engine Mount Replacement

Replacing worn engine mounts stops excess engine movement that can cause clunks, vibration at idle, and harsh shifting. On your Sonata, there are multiple mounts (upper engine-side, upper transmission-side, and lower “torque” mounts) and you typically replace only the failed one(s) unless they’re all aged/cracked.

Difficulty Level: Advanced | Estimated Time: 2.5-5.0 hours

Assumption: Torque specs can vary by mount/bracket; verify your exact fasteners in Hyundai service info if they differ from the values below.

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⚠️ Safety & Precautions

• ⚠️ Support the engine before removing any upper mount (use an engine support bar or a floor jack with a wood block).
• ⚠️ Never put a jack directly on the oil pan without a wood block; you can crack the pan.
• ⚠️ Use jack stands on the pinch welds/subframe; never work under a car held only by a jack.
• ⚠️ Keep hands clear while raising/lowering the engine; mounts can shift suddenly.
• ⚠️ If you remove the battery or battery tray, disconnect the negative terminal first.

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🔧 Required Tools

You'll need the following tools for this repair:

• Wheel chocks
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wood block (2x6 in. approx.)
• Engine support bar (specialty)
• Metric socket set 10mm-19mm
• Metric wrench set 10mm-19mm
• Ratchet (3/8 in.)
• Breaker bar (1/2 in.)
• Extensions (3 in., 6 in., 12 in.)
• Universal joint adapter (3/8 in.)
• Torque wrench (10-200 Nm range)
• Trim clip remover
• Flathead screwdriver
• Pry bar (12-18 in.)
• Needle-nose pliers
• Penetrating oil
• Work gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Right upper engine mount - Qty: 1 (if failed)
• Left upper transmission mount - Qty: 1 (if failed)
• Lower torque mount (rear roll stopper) - Qty: 1 (if failed)
• Lower torque mount (front) - Qty: 1 (if equipped/failed)
• Engine mount fastener set - Qty: 1 (recommended if hardware is corroded)

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Open the hood and remove the plastic engine cover (if equipped) by pulling up firmly.
• If you’ll be removing the battery/battery tray for access, use a 10mm socket to disconnect the negative (-) battery terminal first.
• Plan your support method: an engine support bar holds the engine from above; a floor jack with a wood block supports from below.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Identify which mount(s) you’re replacing

• With the engine off, look for cracked rubber, separated rubber, or shiny “metal-to-metal” contact marks.
• Use a flashlight and inspect the right upper mount (passenger side), left upper mount (driver side), and the lower torque mount(s) (under the car).
• Tip: Replace the worst mount first.

Step 2: Safely support the engine

• If using an engine support bar (specialty), set it across the strut towers and tension the hook/chain to the engine lift point.
• If using a floor jack: place the wood block on the jack pad, then lightly contact the engine at a strong, flat area (typically near the oil pan area). Lift only until you see the engine weight “just” supported.
• Do not lift the engine high yet—only support it.

Step 3: Remove the right upper engine mount (passenger side) (if replacing)

• Remove any air intake ducting or covers blocking access using a flathead screwdriver (hose clamps) and 10mm socket (bolts).
• Spray mount fasteners with penetrating oil and wait 2-3 minutes.
• Use a 14mm-17mm socket (size varies by fastener) with ratchet to remove the mount-to-body nuts/bolts.
• Use a 14mm-17mm socket with ratchet and extension to remove the mount/bracket bolts at the engine side.
• Raise or lower the engine slightly with the floor jack (or adjust the support bar) until the mount slides out without forcing it.
• Install the new mount in the same orientation. Start all bolts/nuts by hand first.
• Tighten fasteners, then final torque:
  • Mount-to-body fasteners: Torque to 75-95 Nm (55-70 ft-lbs)
  • Mount/bracket-to-engine fasteners: Torque to 45-65 Nm (33-48 ft-lbs)
• Tip: If holes don’t line up, adjust engine height.

Step 4: Remove the left upper transmission mount (driver side) (if replacing)

• If access is blocked, remove the battery and tray:
  • Use a 10mm socket to disconnect battery terminals (negative first).
  • Use a 12mm socket to remove the battery hold-down.
  • Use a 12mm-14mm socket to remove the battery tray bolts.
• Support the engine/transmission weight (keep slight upward support) using the floor jack and wood block or the engine support bar.
• Use a 14mm-17mm socket with ratchet and extensions to remove the mount-to-body fasteners.
• Use a 14mm-17mm socket to remove the mount-to-transmission bracket fasteners.
• Remove the mount. You may need a gentle nudge with a pry bar (a pry bar is a strong lever used to shift parts slightly).
• Install the new mount. Hand-start all fasteners.
• Final torque:
  • Mount-to-body fasteners: Torque to 75-95 Nm (55-70 ft-lbs)
  • Mount/bracket fasteners: Torque to 45-70 Nm (33-52 ft-lbs)

Step 5: Replace the lower rear torque mount (roll stopper) (if replacing)

• Raise the front of the car with a floor jack and set it on jack stands.
• Remove the lower splash shield (if equipped) using a trim clip remover, 10mm socket, and flathead screwdriver.
• Locate the lower rear mount on/near the subframe (it looks like a small “dogbone” mount).
• Use a 17mm-19mm socket with breaker bar to loosen the through-bolt(s).
• Use a ratchet to remove the bolts fully, then remove the mount.
• Install the new mount, hand-start bolts, then torque:
  • Lower torque mount through-bolt(s): Torque to 110-140 Nm (81-103 ft-lbs)

Step 6: Replace the lower front torque mount (if equipped/if replacing)

• With the splash shield removed, locate the front lower mount near the front of the subframe.
• Use a 17mm-19mm socket and breaker bar to loosen bolts, then remove with a ratchet.
• Install the new mount and torque:
  • Lower mount fasteners: Torque to 95-130 Nm (70-96 ft-lbs)

Step 7: Reassemble and double-check

• Reinstall any removed intake pieces using a 10mm socket and tighten hose clamps with a flathead screwdriver.
• Reinstall battery tray and battery (if removed) using 12mm socket and 10mm socket. Connect positive first, negative last.
• Reinstall splash shield using trim clip remover and 10mm socket.
• Lower the engine support slowly and confirm mounts sit flat with no pinched wiring/hoses.

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✅ After Repair

• Start the engine and let it idle. Listen for knocking/clunking and watch for excessive engine movement.
• With your foot on the brake, shift from Park to Reverse to Drive. Movement should be controlled and smooth.
• Test drive at low speed first. Re-check mount fasteners afterward if any felt loose or if you heard a new noise.
• If you removed the battery, reset clock/radio presets as needed.

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💰 DIY vs Shop Cost

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

DIY Cost: $80-$450 (parts only, depending on how many mounts)

You Save: $250-$900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-5.0 hours.

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🎯 Ready to get started?

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