In this page we will illustrate how to replace the spark plugs in a 2002 Hyundai Accent GS equipped with a 1.6 L DOHC engine.

 This particular car has over 250,000 miles and it is using some engine oil, due to the oil comsumption, the spark plugs become fauled at earlier intervals, oil fauled spark plugs normally cause engine misfire, that translates to hesitation during acceleration,  if the problem is severe, the car will have a rough idle also due to engine misfire.

 This car was experiencing a hesitation problem during acceleration, the check engine light was on and the engine trouble code found in the ECM indicated a cylinder misfire, the fuel injectors tested ok, we moved our attention to the spark plugs, and we found two of them that had a light coat of baked engine oil, we replaced all four spark plugs and added a new set of spark plug wires, cleared the codes, took it for a test drive and the car was running like brand new again, take note that we didn't perform a complete tune-up on this car because it had one recently, if you want to know the parts involve in a complete tune-up, visit our page Tune-up.

    
    
    
    

    

    



    

    

    

   

  

 

 

 It is recomended to unplug the negative battery cable before working on the vehicle, next remove the spark plug cover as shown in the picture, you will need a 10mm socket, short extension and a ratched to remove the 3 bolts that secure the spark plug cover to the valve cover.














 - Next, gently pull on the no. 1 spark plug wire, pull it all the way out and set it aside.

 

 

  

  

 If you have access to compressed air, blow any dirt that may be trapped in the spark plug cavity off, if any dirt enters the cylinder when you remove the spark plug, it is possible for this dirt particles to get trapped in between the valves and the cylinder head, causing the affected valve to lose its tight seal. This would create permanent engine damage causing a simple spark plug replacement job to turn in to a cylinder head overhaul.

For this reason, make sure that all dirt particles have been blown off.










 Using a 5/8 spark plug socket, a long extension and a ratchet, proceed to loosen the spark plug.

 

 

 

 

 

 

 Some spark plug sockets have a rubber insert that allows you to pull the spark plug out without sliding off, if your socket doesn't have the insert, use a tool similar to the one in the picture to remove the spark plug, if you don't have one, a small diameter rubber hose will do the job.
















 - Next, set the correct spark plug gap, this car calls for  0.043 thousands of an inch.














 - It is recomended to add a light coat of anti-seze to the spark plug threads, this will ensure that no matter how long the spark plug remains in the engine or how hot the engine gets, it will be easy to remove it without damaging the aluminum cylinder head.

Also, make sure that you don't overtighten the new spark plug, overtighting it will also ruin the threads in the cylinder head.












 - We installed new spark plug wires in this car, it is recomended to compare the lenght of the old spark plug wire with the new ones to find the one of equal or similar lenght.

 - Repeat this procedure for all 4 cylinders, when you are done, install the cover back on, install the negative battery cable back on and start the engine, if you did everything correctly, the car should run great without misfiring.













 We took the car for a test drive, it didn't hesitate under acceleration anymore and  it ran like a brand new car.