2. Typically, when replacing spark plugs, you must use a special socket on an extension arm with a ratchet. This head has a rubber O-ring installed to protect the porcelain insulator from damage, as well as to secure the spark plug during installation. You will also need extension cords and a probe to check and adjust the interelectrode gap (see illustration). To tighten new spark plugs to the required torque, you must use a torque wrench.
25.2. Tools needed to replace spark plugs:1. End head for a spark plug - On the inner surface of the head there is a special coating that protects the porcelain insulator of the spark plug; 2. Torque wrench - It is advisable to use it when tightening spark plugs to ensure reliability; 3. Ratchet Lever - Standard accessory in addition to the spark plug socket. When performing the procedure on various models, it is necessary to use various extensions and hinge sections to get to one or more candles with limited access; 4. Extension Rod - To allow one or more spark plugs to be unscrewed or tightened (depending on the car modification) Extensions and universal joints may be needed; 5. Feeler gauge for checking spark plug gaps - Using this feeler gauge, you can check spark plug gaps. Make sure that the gauge is designed to check the gap of the appropriate type of spark plugs.
Note: These models use spark plugs that are 3 mm longer than the standard spark plugs used on earlier vehicles. Make sure that the depth of the spark plug wrench head matches the length of the spark plugs. If a shallow head is used, the ceramic insulator may be destroyed.
3. When replacing spark plugs, first purchase and adjust the spark plugs, then replace each spark plug individually. When purchasing candles, make sure they match the type. The type of spark plugs is indicated in the specifications of this chapter, as well as in the operating manual that comes with the new car.
4. Wait until the engine cools down before removing the spark plugs. While waiting for the engine to cool, inspect the new spark plugs and adjust their interelectrode gaps.
5. Check compliance with the gap standard by inserting a feeler gauge of the required thickness into the gap between the electrodes located on the tip of the spark plug (see illustration). The gap between the spark plug electrodes must correspond to the value given in the specifications of this chapter or on the emission control system information plate. The plate is stuck in the engine compartment. The probe wire should pass between the electrodes with little resistance. If the gap does not comply with the norm, make an adjustment using a feeler gauge, bending the outer electrode until the gap is brought to the required value (see illustration). If the outer electrode is not exactly centered over the inner electrode, use a feeler gauge to bend it. Inspect the porcelain insulator for cracks (if there are cracks, the spark plug is not suitable for use).
25.5a. Spark plug manufacturers recommend using a taper gauge to check for proper clearance. Insert the thin edge of the meter into the gap and turn it so that the meter is sandwiched between the electrodes. Determine the thickness using the scale on the meter. It is prohibited to insert the meter with force and use it to bend the electrode.
25.5b. To change the gap, bend the outer electrode by inserting it into the hole in the meter. Avoid cracking or splitting the porcelain insulator of the center electrode
Caution: When checking the gap of spark plugs with platinum or iridium electrodes, do not pass a feeler gauge between them, as this may damage the coating, which will reduce the service life of the spark plugs. In this case, it is necessary to use a cone thickness gauge.
6. Remove the ignition coils from the cooled engine (see chapter 5). Remove the spark plug boots by twisting and pulling them up slightly.
7. If possible, use a jet of compressed air to remove dirt and foreign particles from the area adjacent to the spark plugs. This procedure will prevent dirt from entering the cylinders when removing the spark plugs.
8. Remove the spark plugs by unscrewing them counterclockwise with a spark plug wrench (see illustration).
25.8. To unscrew the spark plug, use a spark plug wrench with an extension. In order to get to one or more spark plugs, some modifications require the use of extensions of various lengths and sections with a flexible joint
9. Compare each removed spark plug with the spark plugs shown in the illustration to assess the technical condition of the engine (see illustration). Apply some anti-seize compound to the threads of the new spark plugs (see illustration).
25.9a. To determine the technical condition of the engine, inspect the removed spark plugs
25.9b Apply anti-seize compound to the threaded part of the spark plug, avoiding it getting on the lower threads
10. Screw the spark plug in with your fingers, and then use a torque wrench to tighten it. Difficulties often arise when aligning the threads of the spark plug and the hole. To make this task easier, stretch a piece of rubber hose onto the spark plug before installation (see illustration). The flexible piece of hose will act as a joint when the threads are aligned. If the spark plug is misaligned, having a piece of hose will prevent damage to the hole threads.
25.10 Using a piece of rubber hose will help align the threads when inserting the spark plug into its mounting hole and will prevent damage to the cylinder head
11. Put the cover on the coil and install it on the spark plug.
12. Follow the described procedure on the remaining candles.