🔧 ES350 - Ignition Coil Replacement

Your ES350 uses one ignition coil per cylinder (6 total). Replacing a bad coil restores smooth running and prevents misfires that can damage the catalytic converters.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns.
• ⚠️ Disconnect the negative battery terminal to prevent accidental shorts.
• ⚠️ Keep dirt out of the intake—cover openings with a clean rag immediately.
• ⚠️ Do not pull on wiring; release connectors by the lock tab first.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 3/8" drive ratchet
• 6" socket extension
• 12" socket extension
• Torque wrench (in-lb)
• Torque wrench (ft-lb)
• Flat trim tool
• Needle-nose pliers
• Shop flashlight
• Clean shop rags
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 6
• Upper intake manifold gasket set - Qty: 1
• Dielectric grease - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground, set the parking brake, and open the hood.
• Remove any loose jewelry and tie back long hair.
• Use a 10mm socket to disconnect the negative battery terminal and isolate it so it can’t spring back.
• Label hoses/connectors with tape if needed.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Pull up on the plastic engine cover to release it from the rubber grommets.
• Set it aside where it won’t get stepped on.

Step 2: Replace the front-bank ignition coils (easy access)

• Locate the three front ignition coils (closest to the radiator).
• Press the connector lock tab and unplug each coil.
• Use a 10mm socket with a 1/4" drive ratchet and 6" socket extension to remove each coil hold-down bolt.
• Twist the coil slightly, then pull straight up to remove it.
• Apply a tiny smear of dielectric grease (a non-conductive moisture-blocking grease) inside the new coil boot.
• Push the new coil straight down until it seats fully.
• Install the bolt and Torque to 10 Nm (89 in-lbs) using a torque wrench (in-lb).
• Reconnect the electrical connector until it clicks.

Step 3: Remove intake ducting to reach the rear bank

• Use a flat trim tool to release any plastic clips holding the intake duct/resonator in place.
• Use a 10mm socket and 3/8" drive ratchet to loosen fasteners/clamps as needed.
• Remove the intake ducting and set it aside.

Step 4: Remove the upper intake manifold (rear bank access)

• Unplug any visible electrical connectors on the upper intake manifold area (press lock tab, then pull off).
• Use needle-nose pliers to release hose clamps and slide hoses off carefully.
• Use a 10mm socket, 3/8" drive ratchet, and 12" socket extension to remove the upper intake manifold bolts/nuts.
• Lift the upper intake manifold straight up and off.
• Immediately place clean shop rags into the exposed intake openings to keep bolts/dirt from falling in.
• Do not reuse flattened intake gaskets.

Step 5: Replace the rear-bank ignition coils

• Remove the three rear ignition coils (closest to the firewall).
• Unplug each coil connector (press lock tab).
• Use a 10mm socket with a 1/4" drive ratchet and 6" socket extension to remove each coil bolt.
• Twist and pull the coil straight up to remove it.
• Apply a light smear of dielectric grease inside each new coil boot.
• Install each coil, then Torque to 10 Nm (89 in-lbs).
• Reconnect each electrical connector until it clicks.

Step 6: Reinstall the upper intake manifold

• Remove the rags from the intake openings.
• Install new upper intake manifold gasket set onto the manifold (make sure it sits flat and aligned).
• Set the upper intake manifold back into place without pinching any wires or hoses.
• Hand-start all bolts/nuts first to avoid cross-threading.
• Tighten evenly in a crisscross pattern using a 10mm socket and 3/8" drive ratchet.
• Torque to 21 Nm (15 ft-lbs) using a torque wrench (ft-lb).
• Reconnect all hoses and electrical connectors you removed.

Step 7: Reinstall intake ducting and engine cover

• Reinstall the intake ducting and clips using a flat trim tool as needed.
• Snug any 10mm socket fasteners/clamps securely (do not overtighten plastic).
• Press the engine cover back onto its grommets.

Step 8: Reconnect the battery

• Reconnect the negative battery terminal using a 10mm socket.
• Make sure the terminal is tight and cannot rotate by hand.

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✅ After Repair

• 🔍 Start the engine and let it idle for 2–3 minutes; it may run slightly rough at first if the battery was disconnected.
• Listen for hissing (vacuum leak) around the intake manifold; if present, shut off and recheck hoses/gaskets.
• Road test for misfire/hesitation.
• If the check engine light was on for a misfire, clear codes with a scan tool and confirm they don’t return.

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💰 DIY vs Shop Cost

Shop Cost: $450-$950 (parts + labor)

DIY Cost: $180-$600 (parts only)

You Save: $270-$350+ by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.