Deciding if You Should Change the Spark Plugs Yourself

Many newest cars have engine arrangement that makes access to spark plugs difficult. Improper plug changing procedures can ruin the wires of spark plug and the cylinder heads threads. Take the precautions below very seriously before choosing whether or not to proceed. Even if only one condition mentioned below matches your car (and they are true for latest cars), you need to get a professional mechanic change the plugs. Nobody want to risk having to replace a costly ECU just to save a few bucks on a minor maintenance that only has to be performed infrequently. So don’t try to be a hero.

  • Cramped space between the engine parts under the hood that it is challenging or impractical to get at the spark plugs. Remember, you need enough room to use a socket wrench to unscrew the plugs easily and then replace them, and you need to get an unimpeded view of what you are doing. Not only that, if you don’t use the wrench at a precise angle, you may crossthread the plugs or strip the threads, both are disastrous damages to your car. You could end up spending thousands of dollars for unexpected repairs.
  • The entire engine block has to be lifted and dismounted out of the car in order to reach the plugs. If you are a little unlucky to get this kind of car, leave this difficult job to the professional mechanics. Be aware that, studies have discovered that many auto repair shops just don’t bother to lift the engine to get at the hard to reach plugs. If left unchanged, a bad plug can lower your fuel efficiency, make your car a pollution machine, and cause other troubles. So, if your car engine is one of these, if you bring your car in for a tune-up, confirm that the auto repair shop will do whatever is essential or necessary to replace all plugs.
  • Your car engine has aluminum cylinder heads. Because aluminum is soft, it is easy to strip the threads inside the spark plug’s holes. If you do, the cylinder head will probably have to be replaced or removed for repair, and that surely means more money needed for costly repairs. Most modern car engines use aluminum heads, this fact should prevent you doing this job yourself.
  • The spark plugs are located in hidden spots. On a few cars, you can’t get at the spark plugs until you disassemble other parts that are blocking the way. For example, on certain transverse engines, you would have to remove the bolts on the top engine mount in order to tilt the engine block forward to change the rear spark plugs. On other car engines, you can only get to certain plugs through the wheel well area or from underneath. Still other car engines conceal the spark plugs beneath a metal shield that completely covers the engine. Taking away this shield can require unplugging cables that can seriously impair the ECU performance. That is why the aluminum shield is there! On some older local car engines, latest import engines, and a few modern local engines ignition coils are placed directly atop spark plugs. There are no spark plug wires, and you cannot see the plugs until you take out the metal cover that is bolted to the engine.

Leave all these cars to the professional mechanics who use hoists and other special tools that allow them to work easily and safely.