Replacing Spark Plugs!





Introduction: Replacing Spark Plugs!

About: Update 12 September 2017: A very special thanks to Sam Elder, a manager here at Instructables, who tracked down the cause of my lost publications and fixed the issue. Take a bow Sam!

Time to replace worn spark plugs! I bought iridium plugs for longer lifespan and better fuel economy.

Step 1: Remove the Cowling.

On most vehicles there is a cowling to protect the plugs. This one had 3 Phillips head screws to remove plus the engine oil cap.

Step 2: Assemble the Spark Plug Spanner!

I used a heavy duty 1/2inch drive and spark plug deep socket to remove and install the plugs. The extension bar is specifically for getting at spark plugs since it allows for a wobble with the socket.

Step 3: Remove the Plugs.

The driver bar makes it really easy to remove the old plugs.

Step 4: Stupid Design by Kia.

Two of the plugs were blocked by a wire harness. I don't know why engine designers do this crap for. Very very stupid design.

Step 5: Comparing Old and New.

The copper plug has a fat tip whereas the iridium has a narrow tip.

Step 6: Install the New Plugs and Complete the Job.

Installation is the reverse of removal. Tightening of the new plugs should be done with a torque wrench, or in the absence of one, just dont arm wrestle the plug!

Now the car runs a bit better and has improved fuel economy.



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    10 Discussions


    3 years ago

    You should also gap the plugs. Don't assume they are gapped to your car.

    I tried those iridium plugs in my car with no change in gas mileage. Sometimes just replacing worn stuff will improve mileage over non-OEM recommended parts. Think dirty vs clean plugs.

    1 reply

    Iridium is too brittle to risk gaping those plugs. Other electrode materials then sure but I don't chance it with Iridium.

    You forgot one thing: let the engine cool down before you take out the spark plugs or you'll have to get it re-threaded which will not be fun


    3 years ago

    Great basic tutorial for changing spark plugs. Tip: don't forget to put a small amount of copper grease on the spark plug thread. It will make the loosening the plugs much easier!

    1 reply

    My last bit of that I used when replacing some heated oxygen sensors. I will need more of that good stuff since I'm gonna replace my civic exhaust manifold with a performance header. Will post that instructable in the next month or so!

    Ditto on the anti-seize, especially if your engine has aluminum heads. Use permatex copper anti-seize or the like. Also, changing plugs while engine is hot, especially with aluminum heads, is a bad thing; the threads on the heads can wear out prematurely. Lastly, torque wrench would be nice. I never did like the old way of just snugging up the plugs. You want it tight enough to seal, but do not want threads on heads to get damaged. A torque wrench will make the job consistent.

    Nice work!

    I've also scratched my head at some of the design considerations in the engine compartments of my vehicles... "why did they put that thing right there!?" :)

    1 reply

    Some mechanics recommend using anti seize grease on the threads. May make it easier to remove later.

    1 reply