How to Replace Spark Plugs in Chevrolet Cars

by Contributing Writer; Updated June 12, 2017

The plugs provide the spark necessary to ignite the compressed air and fuel mixture in the combustion chamber. Over time, however, the spark plugs will wear out. When this happens, you may notice that your Chevrolet car is harder to start when the engine is cold. It will also generally run poorly and may begin to misfire. Replacement spark plugs can be purchased from most auto parts stores.

Under The Hood:

 How to Replace Spark Plugs in a Chevy Silverado

Remove the black, negative battery cable. Allow the engine to cool. Depending on the temperature and climate it may take the engine 30 minutes to 2 hours to cool.

Gain access to the spark plug wires that are located on the side of the engine. Lift the plastic cover on the side to access the spark plug wires.

Grasp the spark plug wires by the boot of the wire. The wire boot is the cap that connects directly to the Silverado engine. Turn the boot halfway to the right and then halfway to the left to loosen the wire from the plug.

Attach the socket to the spark plug. Turn the wrench to the left to unscrew and remove the old spark plug.

Clean the inside of the wire boot with the wire brush. Lightly spray the boot and threads of the new spark plug with silicone lubricant.

Insert the new spark plug into the engine and manually screw it in place. Use the tension tester tool to find the tension of the spark plug. The appropriate tension level is printed on the spark plug's packaging. Tighten or loosen the spark plug to achieve the required tension.

Replace the spark plug wires. Turn the plug back and forth to lock it in place. Replace the plastic cover back onto the engine and return the battery cable to the battery.

Items you will need

  • 5/8 spark plug socket

  • Socket wrench and extension

  • Wire brush

  • Silicone lubricant

  • New spark plug

  • Tension tester tool

 How to Replace Spark Plugs in a Chevy Impala

Pull the hood release, lift the hood and slide the hood brace into place. Allow the Chevy Impala engine to cool for at least 30 minutes after turning it off.

Locate the spark plug wires. On Chevy Impala models, they are on the sides of the engine. Later models are located close to the top of the engine, while models built before 1989 are located toward the bottom of the engine.

Grab the spark plug wire at the end, or boot, near the engine mount. Turn the wire in each direction until the locking mechanism releases. When the lock releases, pull the wire boot to remove the wire.

Connect the extender and the wrench to the socket. Slide the spark plug socket onto the spark plug. Turn the wrench counter-clockwise until the spark plug is free from the spark plug well.

Clean the spark plug well and the spark plug boot with a wire brush or canned air. If you use the wire brush, gently brush the areas as not to harm any components.

Apply one to two drops of clean engine oil onto the new spark plug threads if the Chevy Impala is more than 20 years old. For newer Chevy Impala models, apply a thin coat of anti-seize compound onto the spark plug threads. No matter what the Chevy Impala model is, apply one or two drops of anti-seize compound inside the wire boot.

Insert the new spark plug into the socket. Place the new spark plug into the well and turn it clockwise to tighten it. Remove the socket and test the spark plug tension with the tension tool. The spark plug package contains the manufacturer's recommended tension for the spark plug.

Place the spark plug wire on the spark plug and turn it half turn in each direction until you hear a click. Gently pull back on the boot to test the wire to see if it is locked in place.

Repeat Steps 2 through 8 on all of the other spark plug wires.

Items you will need

  • Spark plug socket

  • Socket wrench with extension

  • Wire brush or canned air

  • Motor oil or anti-seize compound

  • New spark plug

  • Tension test tool

 How to Change the Spark Plugs on a 2008 Chevy Aveo

Check the gap between the center and ground electrode on all four new NGK IFR6E11 (or equivalent) spark plugs. The correct gap range for the 2008 Aveo is 0.039 to 0.043 inches. If any plugs are not within the specified range, exchange them for new plugs. Do not attempt to adjust the plugs, as iridium plugs are not adjustable.

Remove the four bolts securing the plastic engine cover to the engine, using a ratchet and socket. Pull the engine cover from the Aveo's engine.

Grab a spark plug wire boot -- the thick, rubber end going into the engine -- and pull it upward with a slight twisting motion to remove it from the spark plug.

Inspect the spark plug wire for any visual defects, such as: splitting, cracking, severe aging or brittleness. If any defects exist, replace the spark plug wires as a set.

Remove the spark plug from the engine, using a ratchet, 6-inch extension and a spark plug socket.

Pull the old spark plug from the spark plug socket and insert a new NGK IFR6E11 (or equivalent) spark plug into the socket. Feel for the spark plug to lock into place in the spark plug socket.

Hand-tighten the spark plug into the engine, using a spark plug socket and a 6-inch extension. Attach a torque wrench to the extension and tighten the spark plug to 18 foot-pounds.

Install the spark plug wire on top of the spark plug and press it downward until you feel it "click" into place.

Replace all four spark plugs, following Steps 3 through 8.

Set the plastic engine cover back on the engine and tighten the four retaining bolts to 2 to 3 foot-pounds, using a torque wrench and socket.

Items you will need

  • 4 new NGK IFR6E11 (or equivalent) spark plugs

  • Spark plug gap tool

  • Ratchet

  • Socket set

  • Spark plug wire set

  • 6-inch extension

  • Spark plug socket

  • Torque wrench

 How to Replace the Spark Plugs in a Chevy 350

Open the hood of your car or truck and locate the negative battery cable on the battery. Remove the retaining bolt from the battery cable end with a wrench, then remove the negative cable from the battery. Isolate the cable so it cannot make contact with the battery while you are working on the spark plugs and ignition components.

Locate the spark plugs on the outboard sides of the cylinder heads. Each plug will have a spark plug wire running to it. Select a spark plug to start at--it does not matter which one--and grasp the spark plug wire boot, then pull it off the plug. Twisting the boot as you turn it will help to loosen it if it is sticking.

Install a spark plug socket over the spark plug, then attach a 3/8-inch drive ratchet to the socket. Turn the spark plug counterclockwise to loosen it, then remove it from the head. Discard the old spark plug.

Install a new spark plug into the hole in the cylinder head, threading it in by hand to avoid cross threading it. Tighten the spark plug with a spark plug socket and ratchet. Place a small amount of dielectric grease in the boot on the spark plug wire, then push it on to the plug until it snaps into place on the plug.

Move to the next spark plug in the line and repeat the process, never taking more than one spark plug wire loose at a time. When you have completed all the plugs, install the negative battery cable back on the negative terminal of the battery. Tighten the retaining bolt with a wrench until it is snug, then about 1/4 turn more.

Test run the engine after all the plugs have been replaced to verify it is running correctly. Close the hood.

Items you will need

  • Wrench set

  • Socket set with spark plug socket

  • Ratchet

  • Dielectric grease

 How to Replace Spark Plugs in a 2004 Chevrolet Malibu

Open the hood and loosen the metal securing belt on the air intake using a screwdriver. Pull the air intake off of the engine. Locate the four spark plugs on the driver's side of the engine.

Remove the rubber-covered wire caps from the tips of each spark plug. Remove the spark plugs from the engine using the ratchet and spark plug socket.

Gap all four new spark plugs using the spark plug gapper set to .032. Insert all four new spark plugs into the engine and tighten them to 13 foot-pounds using a torque wrench.

Replace the air intake onto the engine and tighten the metal securing belt using the screwdriver. Close the hood.

Items you will need

  • Screwdriver

  • Ratchet

  • Spark plug socket

  • Replacement spark plugs (4)

  • Spark plug gapper

  • Torque wrench

 How Can I Change the Spark Plug of a Chevy Trailblazer?

Remove the Spark Plugs

Remove the air cleaner assembly from the top of the engine to gain access to all the spark plug wires, if necessary. Pull out the first spark plug wire by twisting and pulling the wire boot. If you have a Trailblazer with a 4.2L engine, unplug the ignition coil electrical connector and unbolt the coil mounting bolt; then pull the ignition coil from the cylinder head. Work with one spark plug at a time to prevent mixing the wires or coils.

Clean the base around the spark plug of dirt and debris, if necessary. Use compressed air or a bicycle air pump. This will keep contaminants from entering the combustion chamber once you remove the spark plugs. Now unscrew the spark plug from the cylinder head using a ratchet, ratchet extension and a spark plug socket. If the spark plug seems stuck, spray the base of the spark plug with penetrating oil or silicone spray following the product's instructions.

Install the New Spark Plugs

Gap the spark plug using a wire feeler gauge. If necessary, consult the Vehicle Emissions Control Information (VECI) label or your car owner's manual for the correct gap specification for your Trailblazer model. The VECI label is in the engine compartment on the top radiator support, firewall or near the strut towers.

Install the spark plug by hand using the spark plug socket and ratchet extension. Then tighten the plug using the ratchet, but don't over-tighten it. Install the spark plug wire, making sure the wire boot snaps in place over the plug terminal. If you have a 4.2L engine model, install the ignition coil over the plug and tighten the coil mounting bolt; then plug the coil electrical connector. Remove and install the rest of the spark plugs following the same procedure. Then replace the air cleaner assembly if you had to remove it.

 How to Change the Spark Plugs in a Chevy Astro Van

Pull the spark plug wire out of the top of the engine. When changing all the spark plugs, only work on one spark plug and wire at a time so that you don't end up mixing up the plug wires. This will mix up the firing order of the spark plugs.

Connect the socket extension to the plug socket. Then connect the extension to the socket wrench.

Lower the socket into the spark plug well. Grab onto the end of the spark plug with the spark plug socket. The interior of the spark plug socket is rubberized and the plug should slide into the end of the plug socket.

Turn the spark plug counterclockwise to loosen and remove it.

Pull the spark plug out of the plug well.

Remove the spark plug from the plug socket. Insert a new plug with the electrodes facing out of the socket.

Thread and tighten the spark plug into the spark plug well.

Slide the plug wire down into the plug well until it sits firmly over the end of the spark plug. You will be able to feel the end of the plug seal over the end of the spark plug.

Items you will need

  • Replacement spark plugs

  • Spark plug socket

  • Socket extension

  • Socket wrench

 How to Change the Spark Plugs on a 2004 Chevrolet Cavalier

Removing the Plugs

Remove the negative battery cable to prevent electrical power to the engine.

If the engine is a 2.2 liter, you will see the spark plug cables and can gently twist them to free them from the plugs. If the engine is a 2.4 liter, unplug the coil connector and remove the four retaining bolts, and remove the coil from the engine. The spark plug cables will be visible; gently twist them to free them from the plugs.

Clean the spark plug well to keep any debris from falling into the cylinder when the plugs are removed. Canned air works well, but if it is not available, a brush or other cleaning equipment may be used.

Use a spark plug socket with the rubber insert to remove the plug.

Installing the Plugs

Inspect the spark plug boot and wire for breaks or tears. Replace the spark plug wire if any problems are found.

Check the gap on the new plugs with a feeler gauge by inserting the proper size wire measure between the electrodes with only a slight drag. The gap size will be found in the owner's manual.

Seat the new spark plugs in the cylinder head by hand. If resistance is felt before the plug is seated, back the plug out and start again to prevent cross threading, which can cause damage to the cylinder head and the spark plug.

Tighten the plug to the manufacturer's specifications once it is seated.

Apply a silicon spark plug connection compound to the boot and plug before re-installing the spark plug wire. Re-install the coil on the 2.4 litre engine.

Items you will need

  • 5/8 spark plug socket

  • Straight socket extension

  • Silicone spark plug boot compound

  • Spark plug gap gauge

 How to Change the Spark Plugs on a 2.2-liter S-10 Pickup

Unbolt the negative battery cable from the battery terminal with the socket wrench and set the cable off to the side.

Detach the spark plug wires from the coil packs on the valve cover in the engine compartment. Pull the wires free from the spark plugs in the cylinder head.

Unplug the spark plugs with a spark plug socket and socket wrench.

Set the spark plug gap at 0.45 mm on a new spark plug, and plug the new spark plug into the cylinder head.

Apply a dab of dielectric grease inside the end caps on the replacement spark plug wire. Plug one end of the wire into the coil terminal and connect the other end of the wire into the top of the spark plug.

Repeat Steps 4 and 5 to install the remaining three spark plugs and spark plug wires.

Connect the negative battery cable onto the negative terminal on the battery. Start the S-10 to make sure the engine turns over and runs normally.

Items you will need

  • Socket wrench

  • Spark plug socket

  • Replacement spark plugs and wires (if the S-10 has wires)

  • Spark plug gapping tool

  • Dielectric grease

 How to Replace Spark Plugs in a Chevy Avalanche

Pop the hood and allow the engine to cool. Do not remove a spark plug from a warm engine.

Locate the spark plug wires. Some Avalanche models have spark plugs running along the sides of the engine, below the engine cover. Other models have spark plugs on top of the engine.

Remove one wire from a spark plug. Clamp the wire puller on the boot, or tip, of the spark plug wire, turn it 180-degrees to the left and pull out. If you remove more than one wire at a time, they need to be marked. If a wire is connected to the wrong spark plug, the engine will misfire.

Attach the socket to the spark plug and turn it counter-clockwise to loosen the spark plug. Remove the socket and turn the plug by hand to release it from the cylinder block. Do not use a flexible extender on spark plugs.

Brush out the wire boot and the spark plug in the engine. Be careful because scrubbing too hard causes damage to the thread and boot.

Spread a thin coat of anti-seize compound over the thread of the new spark plug and insert it into the well. Turn the spark plug to the right to tighten it.

Tighten the spark plug 1/4 turn with the socket to set the plug.

Replace the spark plug wire and turn it 180-degrees to the right and to the left until you feel or hear a click. Repeat Steps 2 through 7 for each spark plug.

Items you will need

  • Spark plug wire pullers

  • 5/8 socket

  • Socket wrench with extender

  • Wire brush

  • New spark plugs

  • Anti-seize compound

 How to Replace Spark Plugs in a Chevy Cobalt

Turn off the Chevy Cobalt and pop the hood. Allow the engine at least 30 minutes to cool completely. Do not remove a spark plug from a warm engine.

Locate the spark plug wires on the engine. These are normally located across the front of the engine. Grab the first spark plug's wire boot. This is the larger piece at the end of the spark plug. Twist the boot 1/2 turn in both directions to loosen the boot and then remove the spark plug wire.

Attach the socket to the extender and the extender to the socket wrench. Place the socket over the spark plug. Turn it one to three times in a counter-clockwise movement to loosen the spark plug. Remove the socket and continue to twist the plug by hand to remove the spark plug from the engine.

Clean the spark plug wire boot with the wire brush. Lightly scrub the inside of the boot to remove any corrosion or debris.

Rub a thin layer of anti-seize compound onto the threads of the new spark plug.

Slide the new or cleaned spark plug into its spot on the engine. Turn the spark plug clockwise into the slot. Use the socket to turn the spark plug 1/4 turn clockwise to secure it. Place the boot on the spark plug and turn it 1/2 turn in each direction until you feel or hear a click.

Repeat the above steps for all of the spark plugs. Do not attempt to remove all of the wires from the spark plugs at the same time. If the spark plug wires are placed on the wrong spark plug, the engine becomes sluggish and it may cause permanent damage to the engine cylinders.

Items you will need

  • 3/8-inch socket

  • Socket wrench with extender

  • Wire brush

  • New spark plugs

  • Anti-seize compound

 How to Change Spark Plugs on a 2.4L Sunfire

Check the gap between the center and ground electrode on the base of all four new AC Delco 41-942, or equivalent spark plugs, using a spark plug gap tool. The correct gap for the 2.4-liter engine is 0.048 to 0.052 inches. Exchange any incorrectly gapped plugs for new ones, as the recommended plugs are not adjustable.

Remove the four bolts securing the engine cover -- the plastic cover on top of the engine that reads "2.4L Twin Cam" -- using a ratchet and socket. Press the locking button on the wiring harness plugging into the driver's side of the engine cover, and pull the harness from the cover -- this harness actually connects to the coil pack assembly, which attaches to the underside of the cover.

Pull upward on the engine cover, using a slight wiggling motion to remove it -- notice the white assembly on the underside of the cover, this is the coil pack assembly. If any of the rubber boots from the base of the coil pack assembly remained stuck to a spark plug, pull the boot from the spark plug with a slight wiggling motion and press the boot back onto the bottom of the coil pack assembly.

Remove all four spark plugs, using a ratchet, spark plug socket and 6-inch extension. Hand-thread the four new spark plugs into the engine, and tighten them to 13 foot-pounds, using a torque wrench, 6-inch extension and a spark plug socket.

Apply a coat of dielectric grease to the inside of all four rubber boots on the coil pack assembly. Line the boots on the coil pack assembly up with the tops of all four spark plugs, and press the coil pack assembly onto the spark plugs until you feel it click into place. Tighten the four engine cover-retaining bolts to 16 foot-pounds, using a torque wrench and socket.

Items you will need

  • Ratchet

  • Socket set

  • 6-inch extension

  • Spark plug socket

  • Torque wrench

  • Dielectric grease

 How to Change the Spark Plugs on a 2003 Chevy Impala

Allow the Impala to sit until the engine is cool. While the engine is cooling, assemble your tools and locate the spark plugs by following the wires onto the engine block. The front three are easy to see, but the three on the rear bank of cylinders are concealed by the intake manifold. You will have to trace the spark plug wires on those with your hands.

Disconnect the negative battery cable. Raise and support the front end of the vehicle. Due to the placement of the plugs on the rear bank of cylinders, it will be easier to remove and install them from underneath the vehicle or through the side. Squirt a non-silicone penetrating lubricant into each spark plug well to aid in the removal of the plugs.

Remove the wire from the first spark plug. Fit the spark plug socket onto the extension bar and attach the bar to the ratchet wrench. Fit the socket over the spark plug and wiggle it until it seats. Gently turn the handle of the wrench counterclockwise. Remove and discard the plug once you unscrew it.

Coat the threads of the new plug with anti-seize compound. Apply a small amount of dielectric grease over the electrode. Guide the new plug into place using the extension and socket. Carefully hand-tighten the plug until it will not turn any more. Fit the ratchet onto the extension and tighten it slightly. Press the spark plug wire onto the electrode until it clicks. Repeat Steps 3 and 4 for the other two plugs on the front bank of cylinders.

Slide under the Impala and remove the spark plug wire from the right-most plug. Fit the socket onto the extension and use the extension to guide the socket onto the plug. Fit the end of the ratchet onto the extension and turn it counterclockwise to remove the plug.

Coat the threads of the new plug with anti-seize compound and the electrode with dielectric grease. Guide the new plug into place using the extension and socket. Carefully hand-tighten the plug until it will not turn any more. Fit the ratchet onto the extension and tighten it slightly. Press the spark plug wire onto the electrode until it clicks. Repeat Steps 5 and 6 for the other two plugs on the rear bank of cylinders. Slide out from under the Impala. Reconnect the negative cable to the battery. Close the hood.

Items you will need

  • Penetrating oil

  • 6 long-life spark plugs

  • Dielectric grease

  • Thread anti-seize compound

  • Spark plug socket

  • Ratcheting socket wrench

  • Socket extension

 How to Change the Spark Plugs on a 2002 Chevy Blazer LS

Locate the spark plug wires -- there are six of them, starting from the top of the distributor, between the rear of the engine intake section and firewall, with 90-degree elbows; there's a seventh, short wire, on top of the distributor, providing the electrical current to the distributor. The seventh wire is markedly shorter than the six ones leading to the spark plugs.

Follow each spark plug wire to locate the spark plug locations. Do not remove the wires from the plugs yet.

Wrap each spark plug with a small masking tape flag and write the plug number on the flag. The plugs on the driver's side of the engine should be numbered as follows: "1" in the front, "3" in the middle and "5" in the rear. The passenger's side plugs should be numbered as follows: "2" in the front, "4" in the center and "6" in the rear.

Remove the plug wires from the spark plugs and position them out of the way -- pull on the wire boot, not on the wire itself.

Clean the areas around each spark plug with compressed air or shop rags. After the plugs are removed, openings will be visible in the cylinder heads -- keep away any debris from entering into the heads, as it is not good for engine operation.

Fold the soft flap inside the passenger's side fender well back to access spark plugs 2, 4 and 6. Remove spark plugs 2 and 4, using a ratchet wrench, 6-inch extension and 5/8-inch spark plug socket. For spark plug 3, attach the 6-inch extension to the ratchet, universal joint to the extension, then the spark plug socket to the universal.

Jack the forward driver's side wheel and place it on a jack stand. This extends the suspension and lowers the driver's side wheel and tire for greater access to the more difficult to reach plugs on the driver's side -- there is a jack point just behind the forward driver's side wheel well; be sure to set the emergency brake before jacking.

Fold the soft flap inside the driver's side fender well back. Locate the steering shaft -- it is the long bar with the orange covering directly in view from the fender well opening. The driver's side plugs will also be accessed through the wheel well.

Slide the orange covering upwards toward the firewall. Additionally, rotate the steering wheel until the flat part of the bar is facing upward. These two procedures allow more access to the number 3 spark plug.

Remove spark plugs 1 and 5, using the ratchet, extension, universal joint and 5/8-inch spark plug socket. Remove spark plug 3, using the ratchet with an extension attached to it, a universal on the extension, a 3-inch extension on the universal and the spark plug socket on the extension.

Set the gap on the new spark plugs to 0.060-inch, using a spark plug gapping tool. Apply a tiny amount of anti-seize compound to the plug threads.

Install new plugs into the number 1, 3 and 5 locations by reversing the removal procedure. Once installed, tighten the plugs just past finger-tight. Torque the spark plugs to 11 foot-pounds with the torque wrench.

Lower the Blazer to the ground.

Install the new plugs into the number 2, 4 and 6 locations by reversing the removal procedure. Use the same tightening technique as for the driver's side plugs.

Reattach the spark plug wires. Pay special attention to ensuring that the wires are attached to the proper plugs. Remove the masking tape flags from the wires.

Items you will need

  • New spark plugs, AC Delco part number 41-993

  • Ratchet wrench

  • Universal joint

  • Socket set

  • 6-inch extension

  • 3-inch extension

  • 5/8-inch spark plug socket

  • Jack

  • Jack stand

  • Anti-seize compound

  • Spark plug gapping tool

  • Compressed air with blower attachment or shop rags

 How to Change Spark Plugs on a 2002 Chevrolet Malibu

Removal

Lift the vehicle hood and support it with the hood prop rod. Allow the engine to cool completely before continuing the procedure.

Twist the spark plug boot for one of the front spark plugs one half turn and pull the boot directly off of the spark plug, working with only one plug and wire at a time. Follow the wire to the coil packs located on top of the intake manifold near the firewall and remove the spark plug wire from its respective coil pack terminal.

Open the new box of spark plug wires and lay them all out next to each other. Straighten out the old wire and use the new wire that matches its length the best. Plug the new wire onto its respective coil pack terminal.

Connect the spark plug socket to the short extension and ratchet. Place the spark plug socket onto the spark plug and rotate the plug counter-clockwise with the ratchet until it is free, and lift the spark plug from the engine.

Installation

Set the gap on the new spark plugs to .060 inches with the spark plug gap tool. Remove the extension and plug socket from the ratchet and insert the new spark plug into the spark plug socket so that the rubber grommet holds it in place.

Set the spark plug into the spark plug hole on the front of the cylinder head and gently rotate it clockwise until hand tight. Tighten the spark plug to 11 foot-pounds with the small torque wrench.

Install the spark plug into the spark plug socket so that the rubber grommet holds the plug, and reach around the engine and thread the rear plugs into place carefully so as to not cross thread the plug into the cylinder head. Tighten the rear spark plugs to 11 foot-pounds with the small torque wrench.

Repeat the removal and installation steps for each plug one at a time to avoid mixing up the firing order of the plugs and wires.

Items you will need

  • 5/8-inch spark plug socket

  • Small Extension

  • Ratchet

  • Small torque wrench.

  • Spark plug wire set

  • 6 New spark plugs

  • Spark plug gapper

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.