'05 997.1 C2 6MT... 39K miles...


I don't think the plugs have ever been done... so I was planning to do that here when I have a weekend off.

question is to eat another $300 and do the coils too?

there have been no codes or misfires of any sort... ignition system seems to be a-ok...


I'm somewhat wary of the "go get the parts-gun" approach, but the labor is just enough to make me think...


is there a "normal" failure mileage for the coils?

 

I did when I replaced my pugs because you have to take them off and they are 9+ years old. Some people like to wait until a part fails to replace which is good because it saves you money by getting 100% life from a component before it is replaced. I am a little more pro-active and replace items before they wear out so I tend to replace items that still have serviceable life left in them but hope it minimizes the potential for break downs.

 

Also time is another consideration for the replacment on your coils - not just the mileage.

GL

 

^^^ fair point...

 

There is no scheduled coil replacement interval on miles or time AFAIK. But to be sure, consult your owners manual. Or better yet, for the most up to date info consult with the dealer service department. If Porsche has changed and implemented a coil replacement interval it will have conveyed this to the dealer's service department.

Barring a scheduled replacement interval, my SOP has been to leave the coils in service unless when changing the plugs the tech advises me the coils need replacing or there are misfires that can be attributed to the coils.

So far that has not happened with either car. One set of coils has over 282K miles on them, the other has over 123K miles.

(Well, check that. The Turbo has misfired a few times: Once after being out the rain all night, again after being out in a heavy fog all night, and quite recently two times from just being out under a carport but with some humidity. The engine has never misfired after a car wash though. However, I think the next time I have the Turbo in for say oil/filter (almost time) I'll have the coils replaced.)

Now if you drive year 'round in all kinds of weather the coils can suffer so you may not get the same coil life as me.

Also, I note while the Turbo has spent its time in an area with good weather the coils are apparently deteriorating. I attribute this to the heat from the hot exhaust/turbos.

But absent any sign of coil problems, misfires, when the plugs are done this is when the coils should be carefully inspected and if signs of deterioration found then the coils should be replaced.

BTW, I would not just replace the one or two that look the worst, but replace all 6. The only time I would replace just one or two coils is if soon after replacing all 6 if one or two coils acted up. This probably arises from premature failure due to defects.

 

^^^thx... that's kinda my personal take on the subject, but I'm still very new to these animals...

 

If it ain't broke.....

 

2 of my coils failed at around 50K miles. These things are known to fail commonly after some years and mileage and since they have to be removed when replacing spark plugs, I would replace them. Relatively inexpensive. When you find out what a bitch it is to remove them and the plugs, you will be happy to know you won't have to go back in there and do it again to replace bad coils down the road.

 

I replaced my spark plugs at 38k miles when i removed my exhaust to put headers on. The coilpacks were in perfect shape, and 2 separate dealer head service advisers told me 60k is when they typically will replace them. I agree with Macster though in that if they look ok, and not misfiring, they really are not that tought to get at. I think removing the headers is the easiest way to access, but you need another set of gaskets. I did not put new exhaust manifold bolts in however, and cleaned the threads on the manifold bolts well before reinstalling them and torquing to factory specs. If you have enough types of flex heads for your sockets, small fingers, and patience you could get at most of them without removing the headers or exhaust (maybe). Good luck!

 

I think it depends on how long you plan to keep the car.

If you are going to keep it long term and if you are doing the work yourself thats different than you are bringing it to someone else to do the work.

Its a good bit of work to get the car up, parts off to get the plugs out and replaced. If you have it all apart to get the plugs replaced then thats the time to replace the coils. Why would you want to repeat all that work to replace he coils latter?

I replaced all the coils on my 06 and found there had cracks in the plastic on 2 coils, no problems to that point, but there were probably going to be problems in the future. I was glad I replaced them when I did.

And really, its only $300. If thats gonna break you, you bought the wrong car

 

I've edited eflight's post to highlight what I would have posted myself.

 

lol, indeed.

the prevalence of bad packs out of the box industry-wide also leads me to an "if it ain't broke"... thought process....