C6 Spark Plug Question
Thread Starter
Burning Brakes
Joined: Jan 2005
Posts: 945
Likes: 61
From: Palm Desert, CA
C6 Spark Plug Question
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
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
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 25
From: Austin Texas
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.
The plugs are very easy to change, I was able to get a torque wrench on all 8 without removing or changing anything.
Team Owner
Joined: Aug 2003
Posts: 24,491
Likes: 312
From: Scottsdale AZ
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
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
Safety Car
Joined: Jul 2004
Posts: 3,867
Likes: 307
From: Wantagh,L.I. New York
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.
Last edited by C8-Vette; Oct 12, 2009 at 02:50 PM.
Pro
Joined: Apr 2008
Posts: 623
Likes: 0
From: Elk Grove CA
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.
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.
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Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
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.
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.
Last edited by dpigguy; Dec 27, 2010 at 06:22 PM. Reason: new data
Drifting
Joined: Apr 2007
Posts: 1,619
Likes: 4
From: Houston TX
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...
Last edited by Ahmer; Dec 27, 2010 at 06:46 PM.
Le Mans Master
Joined: Jan 2006
Posts: 6,642
Likes: 450
From: Texarkana Texas
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.
Safety Car
Joined: Nov 2007
Posts: 4,433
Likes: 873
From: Bay Area CA
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.
Drifting
Joined: Jun 2008
Posts: 1,746
Likes: 35
From: Jupiter Fl
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 !! 
Last edited by Rogers 07; Dec 28, 2010 at 01:26 AM.
Drifting
Joined: Apr 2007
Posts: 1,619
Likes: 4
From: Houston TX
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 !!
