Spark plugs at 90K?

[ultramens]

Hi, I have a 1999 996 C4. I changed my spark plugs at 60K. I am nearing 90K now and was wondering if I need to change the spark plugs again. I know for later MY the interval was increased from 30K to 60K. Was this because newer spark plugs lasted longer?

Thanks for the help.

Oh, the car runs great and has no issues with starting.

[1999Porsche911]

Hi, I have a 1999 996 C4. I changed my spark plugs at 60K. I am nearing 90K now and was wondering if I need to change the spark plugs again. I know for later MY the interval was increased from 30K to 60K. Was this because newer spark plugs lasted longer?

Thanks for the help.

Oh, the car runs great and has no issues with starting.

Depends on whether you are running with copper plugs or not. However, if the car is running fine, why change? Copper will not last as long as will platinum, but both can last far longer than 30,000 miles, primarily because of unleaded fuel. Some will argue that your plugs have to be worn at 30,000 miles, and they are correct. However, so are plugs with only 1,000 miles. But both are still within operating specs and no harm will be done to your engine.

If you are a DIY kinda guy, then change them at your convenience. Otherwise, wait until they start to effect drivability. Depending on how you drive your car, even copper plugs can last 60,000+ miles.

[ultramens]

ok thanks, what should i look for regarding the drivability when the plugs need to be changed....

I have a C4 Tip.

[Loren]

What plugs (exactly) did you put in at 60,000 miles?

If they were the Bosch or Beru 2 prong plugs it would be 30,000 miles - if they were the Bosch or Beru 4 prong plugs then it would be 60,000 miles.

[ultramens]

i dont know for sure. I remember going to advance auto parts and buying them. I think it could be autolite. Any issues?

[Orient Express]

i dont know for sure. I remember going to advance auto parts and buying them. I think it could be autolite. Any issues?

If you did not use the recommended plugs, then change them out at 30K intervals.

[yasuro]

i had misfires at 64k miles on my platinum plugs. i would say that 60k is the longest one should go between changes. i have an 01 C4, 6 speed.

[ultramens]

maybe a dumb question, but how do i know if i have a misfire?

I do not have any engine warning lights.

[RFM]

One of the reasons "check engine" light will come on, you can read out the fault code with a diagnostic tool, which tell you "Misfires on cyl. 1 or 2 or 3 or ...... or random.

[ultramens]

so if i dont have a check engine light, i do have misfires? Thanks

[1999Porsche911]

so if i dont have a check engine light, i do have misfires? Thanks

Misfires will produce CEL.