Iridium Sparkplug change 2008 Chev 3/4 ton 6.0

[Snagglefoot]

My 2008 Suburban with a 6.0 was running well but had 110,000 miles on its second set of Iridiums. The first set made it made from new to 180,000 miles. They had a very high breaking torque so I thought I would not run the 2nd set for as long. The 2nd set were AC Delco 41-110 They came out after almost 110,000 miles. Mileage on the Burb is almost 290,000 miles.

This set are AC Delco 41-162 Iridiums which is the replacement for the obsolete 41-110.
On the left is a new 41-162 and on the right is a 41-110 with 110,000 miles You can see the silver thread compound on the threads. I found it had dried out over the eight years and although the starting torque wasn’t high, the continuous torque to unscrew them was pretty high, sort of annoying when unscrewing 10 complete turns.

 

[Snagglefoot]

I had already replaced two of the plugs and chucked them, but here are the other six. You’ll notice one side of the ceramic insulator has brown staining and the other side doesn’t. The staining might be from intake valve side. The engine consumes 1/2 quart per 5,000 miles. Here are two shots of the six remaining plugs.

 

[Snagglefoot]

Although this was in a truck chasis it seemed the AC lines, and coolant hoses were in the way in different spots. Also, I use a 1/2 inch ratchet to break the plugs loose. Here are all the tools I used. It seemed each plug needed a slightly different configuration to get it out and the new one back in. Plug #8 next to the firewall on the passenger side was the worst.

 

[Snagglefoot]

To get plug #8 out, I removed the front passenger side wheel. I used a normal pair of pliers to pull the boots. On one plug I got nervous about the torque and a gave it some Liquid Wrench. I like to break the lug nuts with a breaker bar then spin them out with a cordless impact wrench. I also spray some Krown on suspension part threads when the wheel is off. So here are the tools for that.

 

[Snagglefoot]

So, looks like I’m good for another 100,000 miles to take the Burb to 400,000 miles, Lord willing!

 

[I<3oil]

That rear passenger plug is a gigantic PITB

 

[Snagglefoot]

I took a few pics of my wheel setup. It’s a 3/4 ton and has 8 lug nuts. Because of the design of the after market alloy rims, it uses splined lug nuts. Removing the nuts requires a spline to 22 mm adapter, and a 22 mm socket. I break the torque with a breaker bar, then use an impact wrench to spin them out to avoid damage to the splines. In the photo I’m using a torque wrench to set the torque to 140 ft lbs. Enjoy.