Q and A: First-timer replaces spark plugs at home
QUESTION: I was wondering if you could talk me through changing my spark plugs. I've learned to change my own oil and filter, and figured why not? It's a 1999 Honda Civic, so it's pretty easy to work on, I think. What tools will I need?...
QUESTION: I was wondering if you could talk me through changing my spark plugs. I've learned to change my own oil and filter, and figured why not? It's a 1999 Honda Civic, so it's pretty easy to work on, I think. What tools will I need?
ANSWER: This is great! You'll need only a few tools and will gain a lot of satisfaction performing more of your own vehicle maintenance. You'll need a 3/8-inch ratchet, a 6-inch extension, and a 5/8-inch spark plug socket. Start by purchasing either a basic 3/8-inch metric socket set (with spark plug socket) or the individual items at Sears or Home Depot, which are affordable but also a healthy step above the cheapo imported stuff found elsewhere. The 6-inch extension is needed to reach the Civic's deeply submerged spark plugs.
Next, purchase the replacement spark plugs and a small tube of anti-seize compound from your local auto parts store. The recommended spark plugs, PFR7N-D made by NGK, are rather pricey but worth the money. These platinum-tipped plugs come pre-gapped at 0.03 inch. I'd check the gap at the parts counter and reject any plugs that aren't correct, as adjustment of the gap is not recommended.
Ready to change your plugs? Make sure the engine is cool. It'll be more pleasant to work on, and you'll reduce the risk of damaging the aluminum cylinder head's delicate threads during plug removal and installation. Gently twist, then pull the spark plug wires loose from each plug and inspect the plastic boot/extension that connects to the spark plug. If cracking or deterioration is evident, a new set of spark plug wires is needed. Also peek inside the tip of the boot/extension -- the metal terminal inside should be reasonably shiny, not corroded.
You may find motor oil around or on the spark plug and/or wire boot, due to leakage of the valve cover seals above each plug recess. A small amount is tolerable, but consider renewing the valve cover gasket and seal if the plug or wire boot are significantly wet (another fairly easy job using your new socket set).
Next remove each plug. If any are tight to turn after the initial break-loose effort, don't proceed! Flood the spark plug recess with WD-40, wait five minutes, and gently tighten the plug back up. Removing it successfully will require professional finesse.
Look at each plug's tip as it's removed -- if any are oil- or fuel-fouled, write down which cylinder it came from for future reference. After applying a small amount of anti-seize compound to the threads, screw the new plugs in finger-tight, using only the socket and extension.
Now attach the ratchet and tighten to 13 pound-feet. Since you don't have a torque wrench, we'll approximate this by grabbing the ratchet handle so that the tip of your thumb is centered over the extension and socket (your hand is perhaps in the center of the ratchet handle, rather than the end -- inefficient on purpose) and tighten with almost all the effort you can. Support the head of the ratchet with your other hand as you twist, as the plug's ceramic insulator can be cracked or broken if the twisting force isn't well centered. Reconnect the wires. That's it!