Spark plug age
Thread Starter
Instructor
Joined: Jan 2020
Posts: 172
Likes: 175
From: Cincinnati
Spark plug age
2015 C7 ZO6. 35000 miles. I have noticed intermittent slightly rough idle and hesitation on acceleration. I am wondering if over 10 yr old spark plugs should be replaced. I took 1 out and didn't look too bad, slight soot and too much gap. Cleaned, regapped. Also age of plug wires? Car is stock, but auxiliary radiator. Car has seen track time
Le Mans Master
Joined: Jun 2019
Posts: 5,484
Likes: 2,193
From: Loveland
Spark plugs are one of those first, easy things to do. Eliminates one thing that could cause issues. Not bad to remove them and see what they look like. As long as they are out, replace with new ones.
Racer
Joined: Nov 2015
Posts: 260
Likes: 87
From: Brighton MI
Fairly easy & inexpensive to replace spark plugs in attempting to determine the source of the issue. Number of years ago I had an almost new spark plug go bad in a motorcycle. Since it was a V-2 it was very noticeable. Replaced both spark plugs with new & issue went away.
Best wishes on sorting out your issue.
Best wishes on sorting out your issue.
Drifting
Joined: Dec 2019
Posts: 1,816
Likes: 616
From: Blacksburg Va
At 10 yrs old I'd replace plugs and wires. Heck I don't see too many here but there have been several threads about coil packs. I think a good case could be made for replacing them but of course they are more $. I try to keep in mind, if I had a cylinder misfiring but needed to get home, I'd rather it were a lack of fuel than lack of spark.
Thread Starter
Instructor
Joined: Jan 2020
Posts: 172
Likes: 175
From: Cincinnati
Thx for replies. I was thinking at 10 yrs, should replace, but also read replace at 100000 miles. Not looking forward to get to all plugs, removing fuse block. Probably use ac Delco, but will look at others
Safety Car
Joined: Sep 2005
Posts: 4,226
Likes: 643
From: Orange County Ca
I doubt that 10 yrs has any bearing on the plugs with normal driving.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
Drifting
Joined: Oct 2005
Posts: 1,354
Likes: 717
From: Terrell North Carolina
Owners manual for Z06 states plugs at 60K miles. no time limit for age, I would say plugs are likely OK, but plugs can cause misfire issues, I would be a more likely issue is wires, heat is tough on the wires, & not as bad of job as plugs.
Race Director
Joined: May 2006
Posts: 10,937
Likes: 478
From: EAST TENNESSEE
I doubt that 10 yrs has any bearing on the plugs with normal driving.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
Are you seeing any codes or cylinder misfires? Could be a coil breaking down,dirty air or fuel filter. Do some checking around first. Good luck.Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Administrator
Joined: Mar 2001
Posts: 368,377
Likes: 24,790
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '26
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
I would guess more a possible issue with the wires than the plugs. Good luck finding out just what’s the problem.
Le Mans Master
Joined: Oct 2014
Posts: 8,673
Likes: 2,728
From: Atlanta GA
Why not just put a code reader on it that reads misfire count by cylinder ? It will tell you if u need plugs
All LT motors idle a bit rough and if you use a misfire counter you will see brand new plugs misfire every now and then . ECM is programmed to ignore occasional misfires . The LT motor is not your fathers Buick ....
36,000 miles on platinum plugs in a stock LT motor NA or Blown .... would be an absolute waste of time and money , not to mention the issues you could have with pulling the fuse box , search the forums to read about how many have had issues with breaking the positive connection off of the box when trying to remove that nut . I know what I am doing and I broke my fuse box and still struggle with it today when I have to take it out ( my car is modified and blown so I do check my gaps every 10,000 miles )
Dave
All LT motors idle a bit rough and if you use a misfire counter you will see brand new plugs misfire every now and then . ECM is programmed to ignore occasional misfires . The LT motor is not your fathers Buick ....
36,000 miles on platinum plugs in a stock LT motor NA or Blown .... would be an absolute waste of time and money , not to mention the issues you could have with pulling the fuse box , search the forums to read about how many have had issues with breaking the positive connection off of the box when trying to remove that nut . I know what I am doing and I broke my fuse box and still struggle with it today when I have to take it out ( my car is modified and blown so I do check my gaps every 10,000 miles )
Dave
Thread Starter
Instructor
Joined: Jan 2020
Posts: 172
Likes: 175
From: Cincinnati
Thx all for advice. I went to autozone, no codes came up. I replaced air filter couple months ago. I can see maybe a 10 yr fuel filter needs replaced or a slightly clogged injector. I'll keep after it. I am concerned issues removing fuse block
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
I doubt that 10 yrs has any bearing on the plugs with normal driving.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
35k miles? Probably not a issue either. Gap a LITTLE big? Probably not a issue either.
Overall, I'd suggest not to change.
I always look at what could go wrong/bad if I do a project.
Remove fuse box--kind of a project and chance of messing up a pin or socket. Messing around with 10 yr old plastic parts in a high heat area concerns me.
Wires and boots are probably ok, but a chance of damaging 1 and need to replace.
But then again, a lot depends on your situation.
Lots of time/money? Plugs and wires probably won't hurt, may help.
Check your throttle body to see if it needs to be cleaned. That is a simple fix for some misfires, especially idle and off-idle misfires.
Bill
Thread Starter
Instructor
Joined: Jan 2020
Posts: 172
Likes: 175
From: Cincinnati
I was hoping Mr Dearborn would chime in. I did clean throttle body when i changed air filter. I seem to recall there were a few drops of oil but it wasn't very dirty. I'm the guy that installed a new battery and pulled that small wire off the negative cable. Which luckily was an easy fix. So I probably shouldn't mess w fuse box