SG Lou

I have 62k on my 04 and have also pondered the idea of changing plugs. I was looking at using AC Delco plugs and the Red GM wires. Then one day, while puttering around under the hood I noticed that it already has the red wires ( they are dirty so I never noticed them before ) so I wonder if the plugs have already been changed.
What do you guys think?

tbrowne

My 04 came with red wires from the factory. Yours probably did too if they say AC Delco on them. I've found that it's next to impossible to remove all of the plug wires without damaging one or two, so you might as well plan on new wires along with the plugs.

SG Lou

I'll have to look for the AC Delco print. I thought they came from the factory with the gray colored wires and that the red ones were sorta like a HP replacement ?

73Corvette

Mine too...

bluestreak63

Is anything wrong that made you think you need to change your plugs? If I'm not mistaken those are 100k mile plugs.

Speaking from experience, don't tinker just to tinker.

Cybermind

IMHO........No such thing as 100K mile plugs. Yes Iridium and Platinum plugs are more resistant but there is no way that sparkplugs with 100K miles retain the same performance characteristics as a fresh set.

At 62K miles, I would definitely change both sparkplugs and wires.

Sparkplugs, wires, O2 sensors, MAF sensors, shocks are types of components that degrade so slowly that you don't notice how bad they really are until you replace them and are amazed at the improvement.

SG Lou

100%

Just ordered a set of GMPP Red Spark Plug Wires and AC Delco Iridium Spark Plugs #41-110

73Corvette

If you would, report back how the install went and what difference it makes... thanks

bluestreak63

Waiting for the "help, I changed my plugs and wires and now my car isn't running right" thread.

strand rider

I have read here that they used whatever color wires were in the parts bin in the later builds , my o3 came with black wires and was built in late 02. But that means little, I bought it used and don't know what it carried new.

At my skill level, if it aint broke don't fix it , carries a lot of weight. A whole lot o' weight. Plus, my enthusiasm for car work is apparently less than most here.

I also agree that electrical stuff can degrade over time. I saw this demonstrated on HotRod TV with a C5 hooked up to a display showing the tighter waveforms of new coils over the old. However, the electrical requirements to meet specs were not discussed, and I have plenty of old electronic stuff that works great. I do plan on looking into the health of my coils, only because of a very slight off note at idle, it is so subtle it might just be characteristic of the design, it doesn't effect my performance needs at all, and is only heard at idle.

That being said, you already have good functional plugs selected for long life over performance. By that I mean effective spark is not a problem with this design, so much so that spark plugs were selected with durability as the main criteria for fitment in this performance car. Copper conducts better than iridium, but doesn't last as long , and some of the die hards put copper plugs in because of this fact about conductivity, and call it an upgrade. With the dealer service price of a plug change in mind, the more durable plug offers more happy customer benefits and no performance downside in this system .

I changed my plugs and wires when I attacked my oil pressure sending unit, using the same stuff on your car now. Mine is a 2003, and benefitted from a revised GM spec, a slightly tighter spark gap , smoothing the idle a bit. I changed because of some milage considerations, but mainly because I bought the car used, and wanted a clean understanding of what I was working on.

I wouldn't mess with the plugs unless you have performance issues or are near the projected end of life. In the old days, with dirty combustion, plugs had a much harder life, and were often featured in ads from parts stores, much as oil is today. Now, the demand has changed, as evidenced by the parts ads that respond to the market place. PLugs are no longer an important performance weak spot , I would save the money and time for other agendas.

Corvette#2

The plugs are rated for 100k miles. But I think the wires can be a weak spot on an older car. I plan to do mine just for fun. But I live in a hot climate. My oil temp has been hitting 230 just in normal, not rush hour traffic.

I once had a low mileage 4 year old 2g Eclipse Turbo that started misfiring badly out of nowhere. One of the spark plug wires insulation had melted through.

The GMPP wires are like $60-70. Cheap insurance.

dadaroo

OK guys, I once asked Evil-Twin about plug gaps and here is his reply. In case you didn't know he was an engineer on the LS1 design team. Thought you might like to read his response.

Quote:

Sam, like many things I find on the Corvette Forum.. too much thought goes in to the finite discussion on things like spark plug gap. Back in the 60 and 70's spark plug gap was much more critical because of the ignition system.

Todays Plugs are designed with much better materials and design. Reach and heat range are dialed in at the manufacturing process. These plugs are designed to go 100,000 miles. Ive seen factory plugs at 100,000 miles with the gap at 0.070 in. without issue. 40 years ago a couple f thousandths could effect performance in a negative way. But Not today. The controversial range in plug gap from 0.040 to 0.060 is the range the plug could see during its life time. I tell people all the time to gap at 0.050 and they can successfully operate within the design even at 0.060. This overthinking is a waste of thought process. I understand everyone want the best. But the plug will properly deliver an Ideal spark and a much wider range than a single gap number.

I hope this helps . there are much bigger fish to fry then debating plug gap. Over kill ( or over thinking ) is a waste of time and money in this case.

There is no concern in a normal wear scenario over the life of the plug. Think of it this way.. if plug gap was critical, the manufacturer would have you chance the plug when the plug gap changed over normal use. Plugs can be successfully use for 100K, GM did testing to insure this when they were testing for 200,000 mile benchmark compliance. That's why Plug scheduled maintenance was set at 100K in the owners manual. IN 100K the plug gap does change, with little to no effect in performance.

Not sure if this helps, but that my thoughts. Bottom line.. too much sweat over a very small issue.