06 C4, 29K...runs great...plugs at mileage cap or its 8+ years..
can plugs if left in too long be impossible to get out?

 

Porsche recommends every 4 years or 36k miles, whichever comes first.

We list the genuine Porsche replacements on our site for reference:

http://www.suncoastparts.com/product/6X99917022390.html

 

It is recommended that you use no anti seize on the plugs. Google NGK and anti seize for details. The plugs will squeak and feel awful as you remove them. I wouldn't extend the service interval, although some do.

 

I have always done by miles. The plugs do not just fall apart In 3 years. They dont deteriorate. They are not like tires or hoses that crack with age.

There are quite a few out there try that wull say otherwise. But those are the ones that like to quote the manual or the service advisor.

None of my cars, and I have had a few, have I ever used time as a reference for plug change.

Your car is most likely out of warranty.

 

Yup! There are stories about plugs getting stuck if left untouched for years. I never experienced this myself.

Plugs are cheap so why take chances?

 

Do plugs ever get stuck? Yep.

What is usually the main cause of a stuck plug? Usually the carbon deposits that get stuck in the threads. Either that, or the anti-seize that is used.

How will a car build up carbon deposits? By being used.

If someone is only driving 3000 miles a year, in 4 years there will be barely any deposit build up.

Are spark plugs cheap? Sure. If you are able to do the job yourself, then go for it. But don't forget to add in the dealer labor. What? Most dealers for that 4 year service like to quote out $1000-1500. That's not cheap.

Is the car running fine? Hesitations? Misfires? Colorful smoke?


For example, my F150, calls for changes at 100k.

If you want, for peace of mind, go and pull one of your spark plugs and take a look at it. If the caps look right and do not a thick coat of oil, put it back in and save your money.

But, by all means, feed your service advisor.

 

FWIW, in days gone by we used anti seize on plugs and they always came out easily without risk to the cast iron heads. But times change. Metallurgy changes. Now the metal on the plug threads is treated for aluminum heads and using anti seize can cause damage from over tightening when torque specs are used. The plugs are designed to be torqued without lubrication. Per NGK and others, anti seize is only to be used on plain metal plugs ... these are plugs that appear black on the threads.

What does this mean? When you do change the plugs expect them to creak and groan and scare the crap out of you as you remove them.

I changed my plugs at 40K/5 years and will state I would not have wanted to go further. I won't go that far next time. That's me. Plugs are cheap and easy to change compared to a head. But it is an individual decision.

 

+1. I only use anti-seize on exhaust nuts and bolts. Never on the plugs.

 

How much do Indies charge for spark plugs only? We should always be aware:
1. If all possible, get a well qualified Indie. Much cheaper than dealer.
2. These are $80,000-$130,00.00+ cars. Relative to the price, what is the percentage of $1,000.00? .

On the other hand, i do my own maintenance.

 

Further to this, Porsche in their wonderfully nebulous way, does want us using anti seize on our lug bolts. And torque values on those lugs have risen over the years!

So you need to do some research before lathering on (or not) the anti seize.

One other point of clarification ... Mine is a Cali car only. No rust or coil problems. Super clean. First two owners were gentle occasional weekend drivers. No carbon buildup on the plugs. The creaking was plug thread to head thread ... spooky. When I expressed concern to others, I was assured this was normal! I suspect this could be worse in other areas of the country.

 

Plugs are cheap but I look to have as little interaction between my car and mechanics as possible. Don't get me wrong. I only put about 3500 miles a year on my car. I change the oil&filter once per year. I also flush/change brake fluid every two years ( dealer maintained). I always warm my car up properly ( easy driving ) before increasing revs. I always drive my car for at least an hour ensuring the oil gets hot. Well, my car is a 2008S and the dealer wanted to change the plugs ( for about $500) about three years ago ( it was four years old) and I declined as it only had about 10 K miles ( I bought it new in 2009). My friends at the PCA club tell me "it goes by miles". My car runs perfectly and I would like to keep it that way. I think about what else can go wrong after they start digging into my engine compartment. Perhaps I am over worried about this but I do believe in maintaining my car well but I also like to avoid new problems. Any real harm in waiting a few more years? ( 18K miles now)

 

Electrolysis happens between different metals. You can't stop the chemistry. And aluminum heads can strip threads easily. I would have been in the don't worry camp if I hadn't changed the plugs myself. The sound of the threads as I backed out the plugs still wakes me at night!!!

I know many may disagree, but time does make a difference.

Car makers want to stretch out maintenance schedules to aid sales. I use their advise as an upper end. If they state time as well as mileage, I figure that there is a reason for that.

I think Porsche has gotten to realistic schedule (20K for oil some years ago was not realistic), and yet it can be hard to read in between the lines.

 

Kinda have the same experience, I changed mine myself , about 5 years and only 15K miles. The plugs themselves looked close to new but they were a little tight backing out.

 

FYI, I don't have any sound issues changing the plugs on my 997.1. No sounds taking out nor inserting. I do extra caution inserting by threading them by hand to avoid cross threading then i torque.

I'm still intrigued by the crunching sounds that I have read from posters. ????

 

On a brand new car? Sure, to keep with warranty and such. But the 997's are hitting 10 years old? 997.2 are hitting 5? Out of warranty? And you can see, many of people on here, including myself, bought our cars used. So, yea, relativity. $1000 on a used 2005 997 that cost $30k? Percentage went way up.

But, then again, I do my own maintenance.

And, the years for me is useless, as I drive my car. So I have always hit miles.