Instructions

Autolite highly recommends that you consult with your vehicle’s owner’s manual for any specific instructions for changing the spark plugs. Engines can vary widely by make and model. These instructions should be considered for general guidance only.

Replacing spark plugs can be a simple job, if you take things one step at a time. Given a basic understanding of mechanical matters, here's a guide to the proper procedures in changing spark plugs.

1. Carefully remove the spark plug wires. Grasp the plug wire boot, twist about one-quarter turn to break the seal, then lift straight off. Use plug boot pullers if the boot doesn't break free easily. Number plug wires with tape as you remove them to avoid crossing them. (illus. 1)

2. Loosen each spark plug so it can be removed. Clean the seat area with a blast of compressed air, or by blowing through a soda straw. This prevents dirt from falling into the combustion chamber when the old plugs are removed. (illus. 2)

3. Remove the plugs and line them up in cylinder order. Inspection of the firing ends of the plugs can identify a number of engine problems that may need correction. (illus. 3)

4. Gap new plugs as recommended in your owner's manual or a Spark Plug Catalog. Use a feeler gauge to measure the gap between the center and ground electrode. The gauge should pass through snugly but easily. If it's too loose or too tight, reset the gap.

5. Screw new plugs in by hand until tight. If the plug starts to go in hard, use a thread chaser to clean the threads. Use a torque wrench to tighten the spark plugs following the manufacturer's recommendations, or refer to a torque chart in the Spark Plug Catalog. If you don't have a torque wrench, see the bottom of the torque chart for hand tightening recommendations.

6. Replace spark plug wires in the correct order. Check to see if the boots are brittle or cracked, and if there is corrosion on the connector inside the boot. If any of these conditions are present, the spark plug wire should be replaced.

7. Start the engine. If it misfires or idles roughly, the wires are crossed or not connected to the plugs correctly. Check the firing order and connections closely.

Autolite highly recommends that you consult with your vehicle’s owner’s manual for any specific instructions for changing the spark plugs. Engines can vary widely by make and model. These instructions should be considered for general guidance only.

Replacing spark plugs can be a simple job, if you take things one step at a time. Given a basic understanding of mechanical matters, here's a guide to the proper procedures in changing spark plugs.

1. Carefully remove the spark plug wires. Grasp the plug wire boot, twist about one-quarter turn to break the seal, then lift straight off. Use plug boot pullers if the boot doesn't break free easily. Number plug wires with tape as you remove them to avoid crossing them. (illus. 1)

2. Loosen each spark plug so it can be removed. Clean the seat area with a blast of compressed air, or by blowing through a soda straw. This prevents dirt from falling into the combustion chamber when the old plugs are removed. (illus. 2)

3. Remove the plugs and line them up in cylinder order. Inspection of the firing ends of the plugs can identify a number of engine problems that may need correction. (illus. 3)

4. Gap new plugs as recommended in your owner's manual or a Spark Plug Catalog. Use a feeler gauge to measure the gap between the center and ground electrode. The gauge should pass through snugly but easily. If it's too loose or too tight, reset the gap.

5. Screw new plugs in by hand until tight. If the plug starts to go in hard, use a thread chaser to clean the threads. Use a torque wrench to tighten the spark plugs following the manufacturer's recommendations, or refer to a torque chart in the Spark Plug Catalog. If you don't have a torque wrench, see the bottom of the torque chart for hand tightening recommendations.

6. Replace spark plug wires in the correct order. Check to see if the boots are brittle or cracked, and if there is corrosion on the connector inside the boot. If any of these conditions are present, the spark plug wire should be replaced.

7. Start the engine. If it misfires or idles roughly, the wires are crossed or not connected to the plugs correctly. Check the firing order and connections closely.

Autolite highly recommends that you consult with your vehicle’s owner’s manual for any specific instructions for changing the spark plugs. Engines can vary widely by make and model. These instructions should be considered for general guidance only.

Replacing spark plugs can be a simple job, if you take things one step at a time. Given a basic understanding of mechanical matters, here's a guide to the proper procedures in changing spark plugs.

1. Carefully remove the spark plug wires. Grasp the plug wire boot, twist about one-quarter turn to break the seal, then lift straight off. Use plug boot pullers if the boot doesn't break free easily. Number plug wires with tape as you remove them to avoid crossing them. (illus. 1)

2. Loosen each spark plug so it can be removed. Clean the seat area with a blast of compressed air, or by blowing through a soda straw. This prevents dirt from falling into the combustion chamber when the old plugs are removed. (illus. 2)

3. Remove the plugs and line them up in cylinder order. Inspection of the firing ends of the plugs can identify a number of engine problems that may need correction. (illus. 3)

4. Gap new plugs as recommended in your owner's manual or a Spark Plug Catalog. Use a feeler gauge to measure the gap between the center and ground electrode. The gauge should pass through snugly but easily. If it's too loose or too tight, reset the gap.

5. Screw new plugs in by hand until tight. If the plug starts to go in hard, use a thread chaser to clean the threads. Use a torque wrench to tighten the spark plugs following the manufacturer's recommendations, or refer to a torque chart in the Spark Plug Catalog. If you don't have a torque wrench, see the bottom of the torque chart for hand tightening recommendations.

6. Replace spark plug wires in the correct order. Check to see if the boots are brittle or cracked, and if there is corrosion on the connector inside the boot. If any of these conditions are present, the spark plug wire should be replaced.

7. Start the engine. If it misfires or idles roughly, the wires are crossed or not connected to the plugs correctly. Check the firing order and connections closely.

Autolite highly recommends that you consult with your vehicle’s owner’s manual for any specific instructions for changing the spark plugs. Engines can vary widely by make and model. These instructions should be considered for general guidance only.

Service Procedure - Removal

• Thin wall 9/16” spark plug socket, various length extensions and ratchet. (Do not use a standard deep well socket)
• Beam or dial style torque wrench, (non clicking type).
• Carbon dissolving carburetor cleaner.
• Compressed air and blow gun.
• Shop Vacuum.
• Nickel Anti-Seize.

IMPORTANT: You MUST adhere to this procedure exactly to prevent breaking spark plugs during removal! Engine must be completely cold (room temperature) before beginning.

Spark Plug Removal

1. Remove coil on plug assemblies and set aside. Using compressed air and shop vac, clean spark plug wells of all dirt and debris.

2. Using a ratchet, back out each spark plug 1/8 to 1/4 of a turn. Fill the spark plug well with carburetor cleaner to just above the hex on the spark plug. (½ to 1 teaspoon) (see illustration #2).

3. Allow a minimum of 30 minutes soak time for the carb cleaner to wick down to the ground electrode shield and soften the carbon deposits at this time.

NOTES: Review the product label on the carburetor cleaner and adhere to all precautionary statements. Use at room temperature with appropriate PPE, (personal protective equipment).

4. Tighten and then loosen the spark plugs working them back and forth to remove. Use the beam style torque wrench and do not exceed 33ft. lbs. removal torque (see illustration #3). If more than 33ft. lbs. is required; place an additional ½ teaspoon of carb cleaner in the well and wait another 15-30 minutes for the carbon to dissolve.

5. Rpeat the back and forth effort working the spark plug loose. Some screeching and high effort will be noticed. Remove the spark plugs.

6. Using the shop vac and a small hose, clean out the plug well and combustion chambers of excessive carb cleaner.

WARNING: Excessive carburetor cleaner in the combustion chamber can cause the engine to hydro lock, remove as much as possible.

Spark Plug Installation

1. New plugs should be installed using a thin film coating of high temperature nickel anti-seize on the ground electrode shield. DO NOT coat the ground strap. (see illustration 4)

2. Tighten spark plugs to 25ft lbs.

The following are general instructions for the removal and installation of glow plugs. For more detailed instructions pertaining to your specific vehicle, consult an appropriate repair manual. Follow all safety precautions.

Technical Tips:

Tip 1: Be careful not to break or fracture the glow plug in the head. If glow plug breaks or fractures in the head you may have to push the pieces into the combustion chamber and remove the pieces through the injector hole using a magnet or claw tool. In some engines the heads must have to be taken out to remove the pieces. Make sure not do damage the threads.

Tip 2: Sometimes glow plugs go bad because glow plug timer system is not working correctly. If glow plugs stay on too long they could burn out. Make sure your timer system is working correctly before you install new glow plugs.

1. Remove the valve cover (Ford) if required.

2. Remove the parts needed to gain access to the glow plugs.

3. Disconnect the electrical connector/s.

4. Using the correct deep socket or combination wrench, remove the glow plug from the cylinder head. Turn a ¼-1/2 of a turn and spray penetrating oil lubricant, turn the wrench or socket back and forth until it feels loose, keep going until is out.

5. Screw the glow plug reamer into the glow plug opening all the way in then out to remove carbon deposits.

6. Install the new glow plug.

7. Reconnect the connector to the glow plug terminal.

8. Replace the valve cover with a new gasket (if required).

9. Reinstall any parts removed for glow plug access.