Macster

60K miles Sigh. Double what the recommended change interval is. I'm so ashamed.

Anyhow, here's the pics:



For comparison, a new plug:



Bumper cover off and resting safely:



Might mention that one bank (one of its plugs pictured) had noticably more deposits than the other bank.

I asked the tech about this, was this a sign of something going wrong, and he said nothing wrong other than what harder driving woudn't cure. I do drive the car a lot but haven't had it out on the open road for a long high speed run for a long time.

It does get run up through the gears from time to time but with traffic so bad in my area one can't do this safely but only rarely and then there's still the unseen LEO that would have me pulled over in no time.

Last but not least, since the other car was sidelined for a week or so waiting for new Michelin tires (which were back ordered until sometime in '14 (!) which then forced the dealer parts department to order Pirelli tires which I agreed to have installed, a new sway bar link (both front links were replaced), then a dead (Moll) battery (died after 4 years), the Turbo has seen a lot of around town usage it doesn't usually see.

Oh, after the plugs were replaced I'd like to think the fuel mileage improved a bit and I'd like to report the engine feels better, but I can't with any degree of confidence.

However, I can't say the new plugs didn't help. Even though I was running around on city streets a lot after the plug change the fuel mileage stayed a few mpg higher than I expected. Also, the engine might (I said might) move off from a standstill a bit smoother.

Coils were inspected and all found ok.

Oh, the front air dam:



Can't see it clearly but the thing is cracked in each of the cut outs too. Pretty banged up.

Anyhow, after thinking this over some this weekend, I chickened out and ordered a factory replacement. $340. I know I know but I just do not trust the aftermarket part and since the original one lasted 90K miles the new one should last that long.

Sincerely,

Macster.

SSST

Mine didn't look quite that bad, but they only had 28k on them. I did notice a considerable difference, but I also replaced the coil packs and o2 sensors.

C2 Turbo

I personally would have replaced the coil packs too. Would coil packs last next 60K miles,probably not, so why not go ahead and replace them and avoid paying for all the labor again.

reynwerkes

I just changed out my plugs at 70k and all looked as bad as shown in the pic.
Don't understand why the previous owner (M.D.) never changed out the plugs. He followed the dealer's maintenance schedule but for some reason the plugs seem to have been missed.
I replaced all my coils also. Each one had cracks in the body.
Interestingly, as the OP mentioned, didn't feel a big difference in driveability I thought I'd notice given the sad shape of the original plugs.
I did install a Cargraphic exhaust at the same time. It's the loud version and I had to admit it is "loud". But so far, I'm enjoying it.

PAULUNM

Considering the cost of coils being less than $300 for a set of 6, and they have to come out anyway when pulling plugs...

I have NO idea why anyone changes plugs and not coils at 30k miles- or more...

Chaos

I had a local guy skip some plugs on a 993 and charge for me for it.

Macster

My instructions to the tech were to inspect the coils and if he found any bad ones, ones that based on their condition to replace them, if necessary replace all of them.

He told me he would and yet he also told me that based the cars they see coils are very rarely bad. When bad there are persistent misfire error codes.

The tech did tell me that sometimes the coils are just fine but the problem comes from some marginal electrical connector/contact of some control wiring and what is done is these are freshened up (cleaned and lubed with some kkind of dielectric grease) which cures the misfire problem. IOWs, the coils is falsely blamed when it is a rather simple to correct wiring problem.

As an aside -- since the car wasn't in for coils and didn't need any I didn't bother to follow up on this so I have to qualify this with a ''IIRC'', but IIRC the older 996 Turbo coils are no longer available, at least not from Porsche.

The 996 Turbo now uses the 997 coils. These newer coils are $90/each and though I get a PCA discount but I do not know how much they are not cheap to replace.

Anyhow, the tech reported all 6 coils looked just fine and were left in service.

I do not want to be too hard on you, but I have to point out that I was similarly advised the coils would not last 'til the next plug change when I had the plugs but not the coils changed in June of 2010 at just under 30K miles. (The car is an 03 so the plugs had been in there for 30K miles and around 7 years.)

Since the plugs were changed at 30K miles, I have now put another 60K miles on these same coils and based on the tech's report, the coils look just fine.

Had I changed them at 30K and then again at 60K (assuming I didn't forget and skip this 30K plug service) and now again at 90K I would have bought 3 sets of coils when so far the original set of coils appears to be working just fine.

Sure, the OE coils could fail tomorrow. That is my risk and one I'm willing to accept. Even if they do, I feel I'm money ahead.

Sincerely,

Macster.

Carlo_Carrera

Because I changed the plugs myself at 30k and I inspected the coils and they were in perfect shape. Why throw away a good part? Let alone six good parts?

PAULUNM

Because the 996 part is prone to cracking?

Same reason people replace coolant hoses, coolant expansion tank, coolant cap as preventative maintenance.

Cheap insurance.

Carlo_Carrera

I hate to tell you but the "new", "upgraded" 997 coils are cracking and failing at the same rate as the old 996 coils did. The shop I take my car to when I need work done that I can't handle myself at home are not replacing 996 coils unless they see cracking. This shop services only Porsche cars and has five service bays that are fully utilized every day. They know Porsches. Just because you replace a 996 coil with the new 997 version is no guaranty that the new 997 coil is not going to crack and fail before your next plug service.

If they aren't cracked why replace a good part?

Danyol

Guys IMO 30k is too long to wait on our cars, I did mine at 24k. We spent a lot of money on them, then skimp on oil changes and plugs?

Macster

24K or 30K is not that much difference unless one is really hammering on the car say doing a lot of track driving.

I don't track my car.

So until I get clear evidence a shorter change interval is needed I'm sticking with 30K. (I just have to remember not to miss a 30K interval!)

You can change the plugs as often as you want. You know how you drive the car and if you are calling upon the engine to make lots of power alot the plugs may very well need more frequent changing.

As for oil/filter services, I feel quite comfortable given my style of driving where I live, etc, that I am in no way skimping on my car's oil/filter service by doing this every 5K miles.

But as with plugs, if you feel a shorter change interval is warranted (based on your usage or just because) shorten the interval.

To me, the idea is to service the car in such a way that when I drive the car I have complete peace of mind the car is being harmed as little as possible when it is being used.

OTOH, there's a limit to what I'll do. If the car is so fragile that it needs so much preventative servicing, too much as to be more trouble than it is worth I'm dumping the thing for a less fragile car.

Thankfully, based on my experience and the experience of other owners, the car does not appear to be fragile at all. Far from it in fact.

The car appears to be, as I expected it to be, quite a well made and well engineered car and a blast to own and drive.

Sincerely,

Macster.

Danyol

Did you notice any change in performance when you finally changed the plugs? Service history on my car showed a plug change at 6k for some reason, I noticed a change in the way the car ran when I swapped them out. Speaking with Kevin i'm not going over 44k on the next round; I do the work, the plugs are cheap. This car is a pleasure to work on compared to the generation of cars I grew up on ("Lucas the Prince of Darkness").

Frissen

damn another thing to add to the list

due to the magnificent economic times we are having my 996TT passed from being a toy to DD under more than terrible mexican driving conditions, basically not having the best of times or put in other words driving the $hi.t out of it

so I decided on two oild changes per annum and attack all other issues one by one, right now I'm going to deal with brakes, new rotors matched to pagids but for next year pehaps I'll do plugs, coils...

I often see 100mph, I usually take the long run from home to office and return on the traffic short run back... so the recommendation is to run it hard and change plugs at 30k miles, I'll will

Macster

Now that I have had more time in the car since the plugs were changed, while it might be just my imagination the gas mileage appears to be a mpg or so better under some conditions: For example city stop/go driving; than it was before the plug change. I have not yet had the car out for an extended high way 'high speed' drive.

The engine I believe (agaIn though it might be my imagination) feels like it accelerates a bit smoother too. I thought I was just being sloppy with the clutch and the throttle but it does feel to me the engine is just a bit smoother now, that some mild stumble/hesitation is now gone when moving the car from a stop. Oh, I'm running the same gasoline (Shell V-Power 91 octane) as before.

Regardless, I will be sure to change the plugs in 30K miles like a good owner and not run them for 60K miles.

Sincerely,

Macster.