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Autopapyrus · Suzuki Swift 1.5 M15A (2008)
https://autopapyrus.com/guides/suzuki/swift/spark-plug-replacement/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Suzuki Swift 1.5 M15A (2008): Spark Plug Replacement

The M15A has 4 spark plugs, one per cylinder. Each plug is covered by its own ignition coil, which sits directly on the plug under the valve cover. The job is not difficult, but it takes care: no dirt should be left in the plug wells, and the plugs must not be overtightened.

Difficulty: Easy Time: 30-45 minutes Steps: 11

Part

  • 🔩 Spark plugs for M15A engine, M14 thread, long thread reach, with gasket washer 4 pcs Alternatives: NGK, Denso

Tools

7
  • Spark plug socket with rubber retainer (16 mm, or the size that matches the installed plugs) with an extension
  • ratchet
  • 10 mm socket for the ignition coil bolts
  • torque wrench
  • feeler gauge for checking the gap
  • compressed air or a thin tube with a rubber bulb for cleaning out the plug wells
  • clean rags
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes AutoFix (online) and 3 more. See manuals →

Step by step

11 steps
  1. Work on a cold engine so you don't strip the threads in the aluminum cylinder head. Turn off the engine and disconnect the negative battery terminal.
  2. Remove the plastic decorative covers and air ducts if they block access to the coils. Remember how they were positioned.
  3. Press the locking tab and disconnect the connector of the first coil. Remove its mounting bolt (10 mm socket) and pull the coil straight up, rocking it gently from side to side. Replace the plugs one at a time so you don't mix up the coils and connectors.
  4. Before removing a plug, blow out the plug well with compressed air. Sand and dirt must not fall into the cylinder.
  5. Unscrew the plug with the socket that has a rubber retainer. Keep the socket straight, and apply smooth, even force. If the plug feels tight, thread it back in slightly, put a few drops of penetrating oil into the well, wait, and try again.
  6. Inspect the old plug. Light brown or gray deposits on the electrodes indicate normal operation. Black soot, oil, or a whitish coating point to problems: a rich mixture, worn valve stem seals, or a lean mixture.
  7. Check the gap on the new plugs with a feeler gauge. For the M15A it is usually about 1.0-1.1 mm; check the exact value for your plug type on the packaging and in the service manual. Do not bend the electrodes on iridium plugs: they are fragile.
  8. Thread the new plug in by hand or with a socket and flexible extension until it seats, using no force, so you don't strip the threads. Then tighten it with a torque wrench. The tightening torque for M14 plugs with a flat washer is usually 20-30 N·m (15-22 lb-ft). Check the exact value in the service manual. Do not use copper anti-seize on the threads unless the plug manufacturer specifies it.
  9. Apply a little silicone dielectric grease to the inside of the coil's rubber boot. Push the coil onto the plug until it clicks into place, tighten the bolt (low torque, approximately 8-10 N·m (6-7 lb-ft)), and connect the connector.
  10. Repeat for the remaining three cylinders. Then reinstall the covers and air ducts you removed and reconnect the battery.
  11. Start the engine. It should start without misfires and run smoothly. If the Check Engine light comes on or there are misfires, check that the coils and connectors are seated securely. Clear the codes and recheck.

Common mistakes and warnings

  • Do not overtighten the plugs: the threads in the aluminum cylinder head strip easily, and the repair is expensive
  • If the coils are cracked or show signs of arcing, replace them together with the plugs, otherwise the misfires will return