vtech

I am curious to find out at what miles on a C6 would be a suggested time to change out the spark plugs for peak performance.

In addition - what brand plugs would you suggest - they look like they would be easy to replace. Are their any corks or hidden issues I should be aware of.

Thanks

haljensen

Unmodified engine the stock plugs are good for a LONG time. Unmodified just replace with stock but don't buy from the Dealer Parts Dept with their huge markup. Any good parts store will have the correct plugs. Unless you notice a performance difference or get a CEL for missfire I'd leave well enough alone.

The plugs are very easy to change, I was able to get a torque wrench on all 8 without removing or changing anything.

Bill Suttie

100K miles

CQRT

The Owners Manual lists sparks plugs to be replaced at 100,000 miles with the following specs:

Spark Plug
GM PART AC DELCO
6.2L V8 Engine 12571164 41-985
7.0L V8 Engine 12571165 41-104

http://www.c6registry.com/Technical/2008corvette.pdf

C8-Vette

For the 6.0 it's Delco 41-110. I like to change them at about 50000 or 60000 miles. If you DIU it fairly cheap. At 100,000 miles there is always a small chance that the threads could come out with the plug, although remote. Do it with a cold engine and coat the new plugs with a dialectric or never seize. Getting to the plugs on a C6 is a snap.

Vinnie T

I'm with you. I get concerned about the threads becoming locked letting them go that long if you don't put a lot of miles on the car. Using an anti-sieze compound is a must.

As far as plugs, you can't go to wrong with the stock plugs. I, however, have had really good luck with NGK Iridium plugs in other cars and will more than likely go with those when the time comes.

Ahmer

Does anyone have the gap specs as well?

Ahmer

Chevy is trying to charge me $500 to do it for me. My car does have 94,000 miles and this whole issue about taking the threads out is starting to scare me.

dpigguy

for the LS3, gap is 0.040 in. per OM.

as for changing, 100k miles as others have said. just go slowly and you shouldn't have a problem. $500 to change plugs ??

for the LS2, gap is also 0.040 per OM.

fressh

You can get the spark gap from the parts store when you purchase your plugs.Don't let it scare you,there's nothing to it.The dealer only wants your money.

OnPoint

$500 for a plug change???

That's crazy.

Ahmer

That's Champion Chevrolet for you here in Houston, TX

Ahmer

I've also been doing a lot of reading about plugs and wire types, I don't track the car. Just want something reliable. Ideas?

Ahmer

NGK TR55 apparently is what everyone seems to be raving about. I also am seeing people say that the stock is the way to go as you will have less Headaches of misfiring with them...

LMB-Z

I changed plugs in my truck at 100k and could not tell any difference whatsoever, in power or fuel mileage. I am not going to change mine in the vette unless I see a drop in power or start getting bad gas mileage. I suspect around 200k or so.

Mike's LS3

The OEM AC plugs and wires work great. I felt more of a difference changing my plugs and wires in the vette at 34k miles than my Tahoe at 100k miles, go figure. In both vehicles, the engines idled smoother and had a crispier throttle response.

VET4LES

I plan on changing mine at 100,000 miles. For me that will be never.

Rogers 07

I just changed mine at 65000 miles. The engine had a slight miss that would come and go every now and then and was slowly getting worse, The old plugs looked fine, After the new AC 41-110 Iridium plugs were in, the miss was still there. So I checked the spark plug wires the old fashioned way, At night in complete darkness with the engine running at idle, it looked like a lightning show at the spark plug boots (Stock original GM wires) 7 out of 8 wires were arching to the exhaust manifold, some so badly you could here the arc !! After doing some research on plug wires, (you might be surprised at what it takes to make a high quality plug wire, most parts store wires are marginal at best !!) I installed a set of Magnecor KV8.5 compition wires. (About $125.00 a set, Expensive,Yes, but very high quality and long lasting performance !!). No more Arcing, No more Missing and a smoother running engine !!

Ahmer

Point TAKEN!

Tikiman12

I'm in way north houston, I'll do your spark plug change in my driveway for free/food/drinks?? lol