I just purchased a one owner 2001 Z28 with 62,000 original miles with no modifications.

It starts up fine, it seems to run and idle fine and the owner manual states that the spark plugs should be replaced at 100,000 miles.

The owner has never replaced the plugs because he never had any problems with it, but the car is 14 years old.

Should I replace the plugs now or wait until 100,000 miles?

Any suggestions?

 

If it still has the factory platinum plugs, they should be fine. "Age" doesn't wear out plugs - miles wear out plugs. Symptom of a faulty plug would be misfires. Misfires cause the SES light to flash, and set codes. I'd be more concerned about the condition of the plug wires than the spark plugs. But again, if there's no sign of misfiring, there's no problem.

If you are still concerned about the plugs, pull a couple and check the condition and the gap.

 

Fred,

Thank you once again for your help.

You are the man.

Hope you guys in NJ are doing OK.

In Washington State, here right now, just a lot of rain.

Mike