Spark Plugs

Basic engine tuneup usually consists of new plugs and wires. Used to be, if you could get 100k miles out of a set spark plugs you did pretty good. I changed White Horse's plugs at 125k but didn't feel the need to change them again until now. With 325k miles on her, it seems like a good time for new spark plugs and new plug wires as well. 

This 6.0 is still strong. No hiccups in the last 12 years. About every 5k miles she burns 1/2 quart of oil. 

Here's a little mechanic's trick. When working over the fender, quarter turn your belt buckle. You won't scratch your truck paint and your britches will still stay up. 

First thing I do before I work on spark plugs is blow all the dirt away from the plug port on the cylinder head. This is a good idea because when you pull the plug out or put it back in you could drag dirt into the combustion chamber.  

Pulling the wire off the plug is one of the hardest parts. Try to avoid pulling on the wire itself. Grab and wiggle the cap over the plug and you should be good. 

They make actual spark plug sockets that have a rubber grommet inside that centers and protects the plug. I like to shoot a little WD-40 on the rubber so that it slides on and off easier. 

Breaking them loose can be tough. Just get a good grip and watch your knuckles. 

Here you can see the old and the new. Definitely needed to be changed. I'm actually surprised these old ones still sparked with a gap like that. Most plugs come pre-gapped with the right tolerance. Though, it's not a bad idea to double check them. I didn't on these. 

Chevy has been running their small block V8 since the 1950's. I'm sure this 6.0 has some tweaks since then, but it's basically the same blueprint. Four sets of plugs on the drivers and four on the passengers. There is less clutter on the drivers side, but you have the steering shaft to contend with. On the passengers there's plenty of hoses and more. A light is usually of help. 

Tightening spark plugs is crucial. It is important to use one hand as a fulcrum on the ratchet head and one to do the torquing. Once the plug bottoms out, I like to give them a good 50 foot pounds of twist. 

I also like to keep all the old plugs in order, so if you see one with some oddities you know which cylinder it came out of. 

If you're going to New York, don't stop in Chicago. We've come this far, might as well replace the wires as well. 

These newer vehicles don't have a distributer cap, but individual coils for every cylinder. Therefore, the plug wires are all the same length. Make sure every one has a good click sound on both ends as you install them. 

Bring it. 

Changing spark plugs and wires is a pretty easy tuneup. Usually you're not out too much cash. And as long as you don't foul anything up, it can only help things. That being said, there's no use doing it too soon. However, 225k miles the same spark plugs is probably long enough. With new territory to cover, we better be ready to run. Let's ride.