Wrench Tip: Creative Spark Plug Removal

by David Zipf

When we picked up our Isuzu Vehicross, we knew that mechanically it was in good shape. However we also knew that the words “preventative maintenance” were not in the previous owner's vocabulary. Most of the fluids looked like they had been present for every one of the 140,000 miles this Isuzu has traveled. While looking at the fluids, we decided to check out the spark plugs to see how long it had been since they had been replaced.

Probably never. When the threads of your plugs are rusted to the cylinder head, it's time for a change.

So we went to the parts store and grabbed a set of brand new NGK plugs for our truck. Four of the six plugs in our Isuzu were easy to change out. The passenger side rear plug was a bit of a problem since the brake lines going to the ABS module passed by it and getting a screwdriver on the coilpack was pretty frustrating. Unfortunately, the driver's rear plug was even worse. Getting the screws out of the coilpack were a nightmare, but then it came time to drop the socket into the bore.

Well that's not going to work.

The brake booster got in the way and prevented the socket from dropping all the way into the bore with our long extension. Now if I had my full toolbox handy I would have simply reached for a U-joint and my short extension, which would have allowed me to dodge the booster and pull the plug.

Unfortunately I am in Kentucky. And most of my tools are still in Delaware. Including my U-joints. Shit. Time to get creative then.

I've been carrying these socket to wrench adapters in my toolbox ever since I got my 240SX (because I read SCC and remember when Dave Coleman recommended these to re-clock the compressor housing of his Disco Potato). So I grabbed the 3/8 drive adapter.

…and jammed it into my short socket extension and then popped that into the sparkplug socket.

This is short enough to clear the brake booster and drop into the bore. But how do we loosen the plug? Well, the head of the adapter is 14mm…

…so I grabbed my 14mm deep well socket and put that on top. This is just long enough to clear all of the castings on the valve cover and break the socket loose. To remove the sparkplug socket, I grabbed the head with a pair of needle nose pliers.

This would also probably work really well on cars with big engines and no tool clearance, such as Ford Mavericks. It might even help on some Subarus as well. But the REAL Wrench Tip here is: when you plan a big move, make sure you pack all your tools the first time.