🔧 Colorado - Ignition Coil Replacement

Replacing the ignition coils on your Colorado is a straightforward repair. The ignition coils sit on top of the spark plugs and create the high voltage needed to fire each cylinder.

Difficulty Level: Beginner | Estimated Time: 30-60 minutes

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before starting. The coil area sits on top of the engine and can stay hot.
• ⚠️ Disconnect the negative battery cable before unplugging ignition coils to prevent electrical shorts.
• ⚠️ Work on one coil at a time if you are new to this. This helps avoid mixing up connectors or bolts.
• ⚠️ Do not pull on wiring. Pull only on the plastic connector body.
• ⚠️ Keep dirt and debris away from the spark plug wells.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4-inch ratchet
• 1/4-inch extension 6-inch
• Torque wrench inch-pound 1/4-inch drive
• Flathead screwdriver small
• Plastic trim tool
• Needle-nose pliers
• Compressed air can
• Shop towels
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-4
• Dielectric grease - Qty: 1 small tube

Note: If one coil failed, you can replace only the failed coil. If the coils are original and mileage is high, replacing all four is reasonable.

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📋 Before You Begin

• Park your Colorado on level ground.
• Shift to Park and set the parking brake.
• Open the hood and let the engine cool.
• Disconnect the negative battery cable using a 10mm socket.
• Take a quick photo of the coil connectors before removing anything. Photos prevent mix-ups.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Cover

• Use both hands to lift the plastic engine cover upward from its rubber mounting points.
• If it feels stuck, use a plastic trim tool to gently help lift at the corners.
• Set the cover aside where it will not be stepped on.

Step 2: Locate the Ignition Coils

• The four ignition coils are mounted in a row on top of the engine.
• Each coil has one electrical connector and one small retaining bolt.
• An ignition coil is the black plastic part that plugs down into the spark plug tube.

Step 3: Clean Around the Coil Area

• Use a compressed air can to blow loose dirt away from the coil bases.
• Use shop towels to wipe around the top of the engine.
• This keeps debris from falling into the spark plug wells.

Step 4: Unplug the Coil Connector

• Use a small flathead screwdriver to gently lift the connector lock tab if needed.
• Press the release tab with your thumb and pull the connector straight back.
• If the connector is stubborn, use needle-nose pliers carefully on the connector body only.
• Do not pull on the wires. Wires break easily.

Step 5: Remove the Coil Retaining Bolt

• Use a 10mm socket, 1/4-inch ratchet, and 6-inch extension to remove the coil bolt.
• Place the bolt on a clean towel so it does not fall into the engine bay.

Step 6: Remove the Old Ignition Coil

• Grip the coil body by hand and twist it slightly left and right.
• Pull the coil straight upward out of the spark plug well.
• If it sticks, keep twisting gently while pulling upward. Do not pry hard against the plastic coil.

Step 7: Prepare the New Ignition Coil

• Compare the new coil to the old coil to make sure the shape and connector match.
• Apply a small pea-sized amount of dielectric grease inside the rubber boot only.
• Dielectric grease is a non-conductive grease that helps seal moisture out of the coil boot.
• Do not pack the boot full of grease. A little is enough.

Step 8: Install the New Ignition Coil

• Push the new coil straight down into the spark plug well by hand.
• Press until you feel the boot seat onto the spark plug.
• Make sure the bolt hole lines up with the mounting hole.

Step 9: Reinstall the Coil Bolt

• Start the bolt by hand first to avoid cross-threading.
• Use a 10mm socket and 1/4-inch ratchet to snug the bolt.
• Use a 1/4-inch drive inch-pound torque wrench to tighten the bolt to 10 Nm (89 in-lbs).
• Do not overtighten. The mounting area can crack.

Step 10: Reconnect the Electrical Connector

• Push the connector onto the coil until it clicks.
• Gently tug the connector body to confirm it is locked in place.
• If you replaced multiple coils, repeat Steps 4-10 for each remaining coil.

Step 11: Reinstall the Engine Cover

• Align the engine cover with its rubber mounts.
• Press downward by hand until the cover seats firmly.

Step 12: Reconnect the Battery

• Reconnect the negative battery cable.
• Use a 10mm socket to tighten the terminal snugly.
• Do not overtighten the battery terminal clamp.

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✅ After Repair

• Start your Colorado and let it idle for 1-2 minutes.
• Listen for smooth idle and check that the engine is not shaking.
• If the check engine light was on, use a scan tool to clear stored misfire codes after the repair.
• Road test gently for 5-10 minutes and confirm there is no hesitation or flashing check engine light.
• If the check engine light returns, the spark plug, wiring, injector, or compression may also need diagnosis.

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💰 DIY vs Shop Cost

Shop Cost: $180-$550 depending on whether one coil or all four are replaced

DIY Cost: $40-$280 parts only

You Save: $100-$270 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 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.