I recently received a free set of Bosch Iridium spark plugs to install and “test drive” through a promotion I saw on The Corvette Forum.

Although my car only has 36,000 miles on it, I figured a new set of plugs couldn’t hurt and since they were free, it sweetened the pot even more. Having changed plugs on countless cars before, I assumed it would take me about an hour to finish the job.

While I was at it, I decided to treat myself to a new set of plug wires as well. I found a set at rockauto.com for a mere $17.22!!! How could I resist? The old wires on my 2003 Z06 were red with black boots while the new Bosch wires were black with black boots. Now I’ve been accused of being a tiny bit **** retentive, but the color of the wire didn’t deter me this time.



I gathered up the appropriate tools, popped the hood and removed the fuel rail covers. I noted that there were numerous obstacles on the driver’s side to deal with so I stared with the (mostly clear) passenger side.

I grabbed the boot to the front spark plug and tried pulling it off. It was tighter than Nancy Pelosi’s face! Part of the problem is not being able to get a good grasp of the boot because of a metal cup surrounding it as well as a sheet metal shield that covers the exhaust manifold. Using a 10mm socket, I made quick work of the exhaust shield which gave me a bit more room. I used a spark plug boot puller (yes there is such a thing, look at the picture I took of my tools) to grab the exposed portion of the rubber boot and after some vigorous tugging and pulling it came free.



Using a short extension on the spark plug socket (from past experience, it’s very important to use a real spark plug socket, trust me) each plug came out with very little effort. My OCD kicked in at this point and I checked the gap of each new plug before installing them. They were all perfect. Then I turned the light switch on and off 17 times, checked the stove and moved on to the second plug.

Getting the boots off the plugs proved to be quite a bit more time consuming than I had anticipated and the first side took me about 90 minutes. I was in no particular hurry to move to the other side, so I took a lunch break, took a nap, checked my email, cut the lawn, painted the house and then returned to tackle the driver’s side.

There are numerous obstacles on the driver’s side. The most glaring are the alternator and master cylinder. As on the passenger side, removing the spark plug boots was by far and away the most time consuming part. The driver’s side took about 2 hours to complete.

After firing up the car, everything seemed normal…in fact possibly better than normal. The engine idle was as smooth as a baby’s behind. I took the car for a spin and it felt as good as new. Time will tell if these plugs stand up to my “spirited” driving style. On October 14th I’ll be at Thunderhill giving them a nice little torture test. I’ll let you know how they perform when I get back.

 

That is the wrong gapping tool for Iridium plugs.

 

what does an Irridium gapping tool look like?

 

The round one as displayed in the OP's photo, are a friction type, which gaps the plugs by scrapping on the electrode and ground. Check out any Iridium manufacturers info on gapping. Friction(round) gapping tools are a no no. You want the type that only adjusts the ground.

 

I didn't gap them. I used the tool to 'check the gap' of the plugs. I think that tool is totally appropriate for checking the plug gap.

 

This should appeal to your OCD.... And it's another tool to add to your collection.

Spark plug gaps are measured with a 'wire' type feeler gauge. The flat feeler gauges are used for valve adjusting. That round thing belongs on a keychain.