When to change sparkplugs?
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Joined: Jun 2005
Posts: 65
Likes: 0
From: Rockport MA
When to change sparkplugs?
How often, and after how many miles should I change the plugs in my C5 vert? When I change the plugs do I need to change the plug wires at the same time?
Does anyone have a recommendation on what plugs and wires to use?
Does anyone have a recommendation on what plugs and wires to use?
Melting Slicks
Joined: Sep 2004
Posts: 3,024
Likes: 18
From: DFW Texas
My 99 is pretty much stock.
WIth 54k on the clock, I replaced my stock Delco's with the Iridium Delco. Kept same wires. Smoothed out the idle considerably. (don't re-gap them - they are pre-gapped at .040)
Get ready to fork out ~~$75 bucks.
WIth 54k on the clock, I replaced my stock Delco's with the Iridium Delco. Kept same wires. Smoothed out the idle considerably. (don't re-gap them - they are pre-gapped at .040)
Get ready to fork out ~~$75 bucks.
Burning Brakes
Joined: Apr 2005
Posts: 753
Likes: 1
From: Oceanside CA
I changed my plugs and wires at 30k. If you change the plugs, you should also change the wires. You will more than likley rip the boots off a few wires so always have a fresh set ready to go. I use NGK TR55's and MSD 8.5 Super Conductor wires with no problems. 
Instructor
Joined: Jun 2005
Posts: 128
Likes: 16
Originally Posted by diyguy
My 99 is pretty much stock.
WIth 54k on the clock, I replaced my stock Delco's with the Iridium Delco. Kept same wires. Smoothed out the idle considerably. (don't re-gap them - they are pre-gapped at .040)
Get ready to fork out ~~$75 bucks.
WIth 54k on the clock, I replaced my stock Delco's with the Iridium Delco. Kept same wires. Smoothed out the idle considerably. (don't re-gap them - they are pre-gapped at .040)
Get ready to fork out ~~$75 bucks.
Plugs gapped at .40? I thought the gap should be .60. I bought a set at Auto Zone. The guy topld me to gap them .60.
Race Director
Joined: Sep 2004
Posts: 17,786
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by jag71usa
Plugs gapped at .40? I thought the gap should be .60. I bought a set at Auto Zone. The guy topld me to gap them .60.
"The guy"
Check the book.
Get Bosch +4s, no gapping and they are great for the $$$ IMHO
Team Owner
Joined: Mar 2002
Posts: 47,647
Likes: 1
From: Queens, New York Life begins at 183 mph....
St. Jude Donor '08-'09
I just changed mine out just shy of the 30k mark. I went with Iridiums and MSD Plug wires. It definitely smoothed out the idle. The stock plugs are notorious for losing their pucks prematurely. Even though they'll get you to 100k, you should swap them out much earlier to keep your performance at its optimum peak. Its not expensive to swap anyway so a good opportunity is to do it at 30k intervals IMO.
Le Mans Master
Joined: Dec 2000
Posts: 9,913
Likes: 1,867
From: Hot Springs AR
If you want to change out plugs for a recreational jaunt, go ahead and change them out at 20, 30, or 50k miles. I changed mine out at 100K (went back with NGK-TR55s) and they were still in good shape. Not one puck was missing (which used to be a problem back in the mid-90s).
Any new set of plugs will smooth out the idle, and maybe give a bit better performance, for about 500-1000 miles, at best. After that, if you're honest with yourself, the engine settles back into it's traditional "lope" or occasional stumble at idle.
I also agree with the comment of changing out the stock wires at the same time (although I didn't
). It is pretty easy to damage one of the wires, and if you're going through the effort of changing out the plugs, the wires are a piece of cake.
HTH, and have a good one,
Mike
Any new set of plugs will smooth out the idle, and maybe give a bit better performance, for about 500-1000 miles, at best. After that, if you're honest with yourself, the engine settles back into it's traditional "lope" or occasional stumble at idle.
I also agree with the comment of changing out the stock wires at the same time (although I didn't
). It is pretty easy to damage one of the wires, and if you're going through the effort of changing out the plugs, the wires are a piece of cake.HTH, and have a good one,
Mike
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Pro
Joined: Apr 2005
Posts: 666
Likes: 5
From: Mt. Pleasant SC
Originally Posted by jag71usa
Plugs gapped at .40? I thought the gap should be .60. I bought a set at Auto Zone. The guy topld me to gap them .60.
Instructor
Joined: Oct 2004
Posts: 134
Likes: 0
From: Arlington Texas
I kept mine in for 160k plus and never had a problem. If they aren't missing, or your mileage isn't going down, whay mess with them. The only reason mine are changing now is I am pulling out my engine and installing one of Andy's forged blocks and his supercharger. So, unless you're running your vette at the track, save your bucks for something that actually NEEDS replacing.
