rjshar

I agree. All of my coils appear to be operating just fine, but they are now 9 years old and have 80k miles on them. I guess if I were ultra nit picky, I would say there are some slight variations in idle consistency, but nothing that has given me any concerns. I'll reply back if the coil pack change has an impact on this.

I'm also thinking about documenting my procedure so that we can have pictures of the bumper removal and muffler removal process on a 4S with PSE.

Wish me luck! I just ordered the parts so it should be about a week or so.

Wayne Smith

Both times I replaced my plugs (2010 C4S PDK) I left the bumper on ...

1. Put the back on jackstands.

2. Pull the rear tires (use stud locator pins).

3. Remove the fender support braces (from the lower back side of the wheel well to the frame) to make space for the mufflers to come out through that space.

4. Remove the muffler tips.

5. Remove the mufflers.

6. Remove the top half of the heat shields that cover the coils.

7. Remove the coils.

8. Remove the plugs.

9. Reverse the steps, using new plugs and, if you feel the need, new coils.

Do not use anti seize on the plugs. The metal threads are coated (silver color) and, if you do some research, should not be covered with anti seize (only uncoated black threads use anti seize).

Since I haven't done this job by removing the bumper I can't absolutely say the above method is better. But I see no advantage to having the bumper off (some may argue the left muffler's top bolt can't be removed without removing the bumper ... not true). In exchange for leaving the bumper on you need to remove two bolts on each fender brace bracket. I figure that's a win.

docdrs

Bruce In Philly

Wayne, I don't remember.... when you leave the bumper on, you have to remove those evil cat nuts no? Can you leave the bumper on and not do the cat nuts? I did three plug changes now, the first I did was with the bumper on, and I removed those three evil cat nuts. I do remember I could not get the tips off but it turned out I could pull the mufflers off of my S without removing them (I am sure of that). If you leave the bumper on, and a cat nut shears, what do you do?

The first time I did this, the cat nuts were a royal pain but I came up from below to get at them (using a friend's grease pit - anyone remember those things?) but they didn't break. They did break when I removed them again to put on my Sharkwerks cross pipe and I can't imagine repairing them without removing the bumper.... I think.

I am sure there are a few different ways to do this job.

Peace
Bruce in Philly

rjshar

Bruce, this is specifically why I am going to go the bumper removal route. I'm not that concerned with time. I am more concerned about sheering bolts. With the relatively high mileage and salt exposure of my 4S I think the bumper removal route is the most prudent option. Additionally, I have PSE so I think the side mufflers with vacuum lines also give me another reason it would be beneficial to have the bumper off. Plus, it's not that difficult to take a bumper off.

-Ravi

Wayne Smith

I did not have to loosen the cat nuts. I'm not sure why having the bumper on or off would make a difference here.

The mufflers pull out toward the front.

The top half of the heat shield removes the same with or without bumper.

Not removing the bumper is simply a step less.

Wayne Smith

Good point on PSE. I don't have that (Fister mid instead). PSE could make a difference. A friend's car has PSE and plugs that are due. I'll know soon if that requires a bumper removal. Update us after you do your plugs.

docdrs

The cat nuts only need to be loosened and removed to take the center muffler or x pipe off. The joiner clamp between the center muffler or xpipe and the side mufflers has to be loosened to remove the mufflers. The mufflers can be removed with the tips on, it just takes more manouvering to get them out. Pse may make it more difficult and the tips may have to be removed to give more room.

I had a friend stop by when i was doing the passenger side just before I reattached the coil wires......boy did it run rough and thro codes. I had to loosen the mufflers and heat shield to reattach clips and that was tight but do able. No way to get coil packs and plugs out without removing mufflers on a 997.2.

rjshar

So after ordering parts on 12/22, I finally received my order on 1/12. I guess I'm getting spoiled by all of this 2-day shipping, but that seemed like forever to me. I'm hoping to have time this week to tackle this job.

One thing I wanted to note for anyone who may attempt this in the future:

I ordered Porsche OEM coils, and when they arrived I was expecting them to be labeled Beru, but they were actually labeled as BorgWarner. Beru is and aftermarket company that was acquired by BorgWarner, so I think these are the appropriate parts, but I just wanted to post this out here in case anyone got caught by surprise in the future.

997.2 Ignition Coil:
Porsche Part No: 9A160210407 (Porsche box with BorgWarner stamped on the actual coil)
Beru Part No: 9A160210406

This makes me wonder if there has also been some sort of revision to the coil packs for 997.2's. I know that 997.1's had issues with coil packs cracking, and ultimately had an updated coil pack hit the market. Has anyone else here dug into this?

rjshar

Alright, so I took off the rear bumper, got the exhaust off, got the coils off, all was going extremely smooth...

Then, I got to actually removing the plugs. Those things were super deep in there, and very tight. So tight, it got me scared that I would end up sheering the plug in the head. So, basically, I chickened out and put everything back together and am taking them to a shop to have them installed tomorrow. I didn't think they'd be that tight after 2 years and 40k miles, but for me, it's worth the insurance to leave this one to the professionals.

Lessons learned:
- I would definitely take the rear bumper off again. It was really simple and made access to everything so much easier.
- Definitely have spare exhaust bolts handy as mine snapped very easily and will need to be replaced.

Thanks to everyone in this thread for the tremendous culmination of knowledge here. I will let everyone know if I notice anything after installing new coils. I will say, the coils I pulled out were Beru(BorgWarner aftermarket), and the new Porsche coils that are getting installed tomorrow are stamped BorgWarner.

Thanks,
-Ravi

tinkerbill

I bought a used 2009 C2S and at ~16,000 mi I replaced the plugs in hopes of curing some rough running. It didn't. All 6 plugs were scary tight.
You can get the driver side problem cat nut off with an extension out the back where the exhaust tip was removed but the passenger side nut requires a crow foot or ratchet wrench to remove. I left the rear bumper cover and bumper on the car,

turbozv

Just replaced spark plugs again after 4 years, it did take longer this time, because I thought I remember the procedure, but it turns out my memory is not that good

eagle1960

Both can be removed w/o a crowfoot or such if you use a swivel as I have done several times working on plugs, exhaust, etc.

docdrs

bhvrdr

I just did the plugs and coils this past weekend. Ended up wasting money since both were in absolutely terrific shape but oh well. I did not remove the bumper, the wheels or the mufflers. I only removed the 2 heat shields and slid them out of the way. It was tight but it worked fine.

I used this for many of them...


Mike