I have a 2003 350z, with 72k miles. I'm pretty sure the car still has the original plugs. I know a lot of people reccomend 100k miles, but is it worth changing them now? I mean it has been 9 years now on the original plugs...

 

why not

 

I guarantee you your car will run better if you replace them. VQ's aren't nice to plugs..

 

check if oils leaking into the spark plugs first, then knock out the valve cover gaskets and spark plug change all in one go.

 

You will likely find oil in the spark plugs wells, but it won't be the valve cover gasket that is the culprit. There are indivual seals for each spark plug well that are built into the valve cover.

There is a company that will sell the individual seals, but you have to cut your valve cover to remove the old ones. If you mess up then you have to get new valve covers. That same company offers valve covers with the seals already replaced and its not to expensive if you send them your old valve covers once you are done.

 

If they aren't leaking that much is it even worth the hassle? Do they claim to use different or better seals?

 

There is a thread here with a set for sale.

 

I just replaced mine with 82k miles. NGK iridium is only way to go. They are like 8.20/each at orielleys. My plugs at 82k didn't look to bad but why not spend $50 to treat the z with a lil love.

 

I changed mine on my 03 at about 60K. May have been psychological, but the car felt a little refreshed after.

 

i've tryed to get in truch with the people you where talking about and no replay or the web site is down r b something if you have any updated info would you please let me know thank you my z leaks 4th

 

Have 86K on mine.... just changed out OEM's out. WOW what a difference.

Ironically RockAuto had the best price.