How to change your spark plugs
Published 12:00 am Sunday, August 7, 2016
Q: I want to change out the spark plugs that I recently purchased for my 2005 Honda Accord EX, which has a 2.4-liter four-cylinder engine. They are NGK brand plugs with a model name of 1ZFRK11. What should I do?
A: I’m going to assume you’re new to this, so I’ll give you a thorough explanation.
Let’s start by making sure your car has the super ultra-low emissions version of the 2.4-liter engine. If so, there ought to be an identifying sticker on the valve cover. If it’s not, you need to use 1ZFRK13 spark plugs.
Honda recommends replacing your spark plugs at the 110,000-mile mark, and there’s nothing wrong with changing them early.
You’ll need a 3⁄8-inch ratchet, a 6-inch extension, a 5⁄8-inch spark plug socket and a 10-millimeter socket. A 3⁄8-inch drive torque wrench is also recommended. Also make a stop at your local auto parts store for a tiny tube or pouch of spark plug anti-seize compound.
To prevent possible thread damage, don’t remove or replace your spark plugs unless the engine is cold. Your four spark plugs reside beneath a rectangular plastic coil appearance cover and four ignition coils. Use the ratchet and 10 millimeter socket to remove the cover and each of the coil’s retaining nuts. The coils can then be gently unplugged from their wiring connector and pulled up and out of the spark plug wells. Twisting the ratchet counterclockwise atop the extension and socket, remove each of the spark plugs. If any are tight as they are rotating stop right away. Liberally apply penetrating oil, wait an hour, retighten and leave that plug for a professional to remove. Practice holding and supporting the ratchet head as you apply force so the spark plug socket and extension remain as vertical as possible. This will be important when you’re installing the new plugs.
Inspect each of the new spark plugs to ensure its electrode gap is equal to the others. They come preset. We’re just being sure none have been damaged.
Now the controversial part: Honda recommends putting a small dab of anti-seize compound on the spark plug threads, while NGK, the plug-maker says not to. NGK states the silver color visible on the threads of their plugs is a trivalent coating that resists corrosion and thread-binding. The company’s concern is anti-seize compound, a lubricant of sorts, can result in over-torqueing of the plug and damage to it. Anti-seize is also thought to reduce electrical and thermal conductivity between the plug and cylinder head. I’d lean toward Honda’s recommendation and apply a tiny dab (half a baby aspirin at most) to each plug, rubbing it into the threads.
Thread each spark plug in clockwise until hand-tight, using only the socket and extension. Supporting the head of the torque wrench, tighten each plug, twisting gently clockwise until the pointer indicates 13 pound-feet. Do not overtighten! Before installing the coils, check for punctures, cracking or other deterioration of each coil’s plug boot. Replace the coil if damage is evident. Also, if a pool of oil is found in any of the spark plug wells, renewing the well-tube seals may be necessary. The 10 millimeter nuts retaining the coils and coil cover should be snugged to only 7 pound-feet of torque, so don’t use the overly powerful torque wrench. Instead, hold the 3⁄8-inch ratchet with your hand right next to the head and apply slight-to-moderate force. Too little is better than too much.