Hello All,
2005 Carrera 997.1
I changed my plugs in 2010 and was wondering how many of you have actually experienced spark plugs
sticking in their bores after not being changed for longer than 4 years. When I installed them I didn't use antiseize
but I did use a drop of oil on the threads on each one, recommended by a Porsche indy shop nearby.
Experiences/opinions welcomed.
Thanks!

 

Modern spark plugs have a built in coating that acts as a one time anti-seize. Unless the plug threads are black do not use anti-seize.

This one time anti-seize coating is destroyed when the plugs are installed ... Use the plugs once, don't use them again.

I question the oil as well. Oil will lubricate the threads and could cause you to over torque the plug resulting in a stretched or broken spark plug or eventual future block damage. Oil will be a non conductive insulator. And over time it will burn off leaving a carbon blanket.

I've changed my plugs three times now (2010 C4S with 135K miles). I've changed plugs for friends as well. All were within the four year period. All creaked during removal.

When you tap new threads you reverse the tap direction from time to time to clear the chips. The first time I changed my plugs I tried reversing the direction and the plugs jammed badly. Chips, with no where to go (taps have flutes that allow the chips to escape), were getting deeper into the existing threads by reversing the direction. Don't do this!!!! This indicated to me that either the one time anti seize was shedding or that electrolysis had been playing havoc over time causing metal to be ripped from either the plug or the block.

In all my changes I saw no damage to the block. My feeling is the jamming and creaking was the softer one time anti seize coating sacrificing itself. Electrolysis was not a likely culprit IMHO.

So this argues that the time isn't necessarily important. At the same time I would not be inclined to risk it. These plugs are easy to change. Just do it.

 

Had my 2005 C2 original plugs changed at about 32k miles, after about 13 years - no issues reported by the Indy

 

Non DFI cars don't seem to see this issue, ie the plugs will typically come out fairly easily even if original. But, later DFI cars such as 981 and 991 do show signs of spark plugs fighting to come out fairly regularly, including requiring the use of breaker bars in some instances.
For this reason I'm adamant about the intervals on these cars specifically, but not as much so on the earlier watercooled. Especially when it comes to time as opposed to mileage.

 

Consistent with some of the other experiences noted, I had no issues with a recent replacement of the (original) spark plugs. 2009 C2S (11 years old now). 27k miles.

I will comment that when I examined the old plugs after they were out, I was especially glad to have had the job done. I had contemplated waiting on doing the work as the car performed just fine and also in consideration of the comparatively low miles.

The car runs noticeably better now.

 

A drop of oil is the proper way. Don't use anti seize as it can effect the plugs ability to ground to the head and cause electrical or poor running issues.

 

Aren't anti-seize compounds (like Permatex 80078) typically made of metallic particles and graphite (conductive materials)? If used according-to-instructions/sparingly, might conductivity not be an issue?

 

Fwiw, i changed the plugs on my newly acquired 991 a couple weeks ago, they were in for 2 years and 10k miles. They were not hard to remove but no where near as smooth on removal as those in my 997rs or any of my air cooled cars.

id not go longer than 4 years.

change the plugs!

the plugs were fine condition. Even wear and color

 

I burned through the carbon button on a distribute cap on my 914. Jake told me it was because I used anti seize on the threads and to never do that and just use a drop of oil. Though the 997 doesn't have a cap, the premise is the same with respect to the plugs properly grounding.

 

I just read that most spark plug manufacturers do NOT recommend anti-seize because the specified installation torque value is based on a dry installation and that over-torquing is almost guaranteed. If you do lube with anything, decrease the installed torque by about 20%.

With regard to whether spark plugs need an anti-seize agent to allow for more easy future removal - most modern spark plugs come with an electroplating which is an anti-seize - these threads are normally "silvery colored". (The plating is also "single use".) "Black" thread spark plugs are probably better off having anti-seize compound applied.

 

This!!! And ...

https://ngksparkplugs.com/en/resourc...ut-spark-plugs

The corona mentioned in paragraph two makes me question using oil. Well, that and paragraph one where it specifically states the plugs should be installed dry.

 

Iridium plugs go 60-100k miles in many cars out there. Even if 40k is advisable for Porsche , plugs sit in millions of cars for 10 years or more and come out ok. I'll be changing mine around the 40k mile mark, but I don't believe so much in the time issue within reason, compared to other cars, for a street driven NA car.

 

I don't put anti-seize on anything that isn't meant to come out on a fairly regular basis AND which are not critical parts. I think anti-seize is recommended way too often on this forum. I've even seen people suggest anti-seize on the threads of lug bolts and suspension components where a backed-out bolt would cause major problems.

Oil is usually added to the threads of things like head bolts in engine assembly as the torque value is critical and only accurate with a little lube. Torque readings are more suspect when things are assembled dry. I don't see any reason not to use a little on the threads of spark plugs. There is massive contact area for a ground and the oil isn't going to interfere with that--either wet or cooked.