deilenberger

Without knowing what your 4 year consisted of hard to say what is needed at this point. Misfires are typically plugs or coils. Plug failures are pretty much strictly mileage based. Coil failures are age, mileage and heat based.

Bxstr

How many miles are on your car?

I would replace plugs and coils. Sounds like it is the one coil, but while you're in there, you probably should do all of them. You can order OEM (without the Porsche logo) to save some money over the genuine part (with the Porsche logo). Same part for the most part, although some say the Porsche plugs have better quality control.

DiabloBlanco

I have 14K on my car and do not track it. I did everything required by the manual for the 4 year service,...which included spark plug changes. I take the mechanic's word that they used OEM parts.

Anyhow, taking this to the shop this week. Wish me luck.

DiabloBlanco

Just FYI, had my car towed to my mechanic (GT International in Austin, TX). It looks like the code reader I bought was spot on as they saw the same.

They recommended to only replace the one coil that was misfiring. Kind of awesome to know that they didn't push for all the others as it would have pushed the price of the service. If I had gone to the dealership, I'm sure they would have recommended replacing all coils and charging me an arm/leg on the labor. (note, the tow cost more than the actual parts/labor).

Thanks for all of the feedback. I always appreciate the insight from this group!

storii

On the contrary, replacing all 6 coils at once will be cheaper than replacing one at a time for potentially 6 times. Let alone the towing cost and your time to deal with the trouble. As someone said before, when one coil goes others are also on the edge. My wife's DD, a 2013 BMW 128i, got misfires due to a bad coil last spring. I took it to the dealer and they replaced just the bad coil. The car is SULEV so all parts and labor relating to the emission control are covered by the 10-year/10k-mile SULEV warranty. I pushed the dealer to replace all 6 but he wouldn't budge. Sure enough, a second coil went in the following week and the dealer replaced all remaining 5 this time. YMMV.

ledbette

All hell breaks loose when a coil goes on you. Scared the crap out of me the first time it happened. It was about 6 months after my warranty expired and I was sure it was going to be something expensive.

Not sure what model you have, but coil 5 and 6 are extremely common failures on the 981 due to proximity to the catalytic converter on the driver's side. I had to replace both about 2 years ago about 3 months apart. No problems since.

I also purchased and installed the 991 coil heat shields on my 981 earlier this year. Not sure why the 981 does not include them, but I think they will significantly improve the coil longevity, especially if you spend any time at the track.

ekam

Replacing only 1 coil instead of 6 means they really want your business down the road.

I would stay away from shops that make these types of "recommendations".

ledbette

The first time this happened I took it to the dealer. They didn't get around to the car for 2 days, so I did a little research on the problem and picked the car up and did it myself. Saved myself a couple hundred stealership dollars. Now I just carry a spare to the track in case I have one die. The 5 & 6 coils are a lot more susceptible to heat degradation. Replacing all 6 does not address this problem, just costs you a lot more in parts and labor.

Noah Fect

And if they recommend replacing all 6, I'm sure no one will accuse them of trying to inflate the bill by replacing parts that haven't (yet) failed.

The shop can't win. The only safe thing to do is to err on the cheap side.

storii

The coil heat shields sound like a great idea. I read in a review that while the "upper shields" are easy to install, the "lower shields" are impossible to install because the OEM headers block the bolt holes. Do you know if the upper shields protect the 6 & 5 coils or vice versa? Also, will aftermarket headers make the installation of the lower shields somewhat easier?

txbdan

Yeh i got stuck where i got the upper shields on but not the lowers. You'd need different screws for the bottom shields, OEM screw heads are too long to clear the stock cats. They reportedly can work with aftermarket cats. The good news is the upper shields are the ones that cover the coil packs. The lower shields are still on my to-do list.

ledbette

I had to unbolt the headers to fit the lowers, but they came off and went back on fairly easily. Porsche recommends replacing the header bolts and gaskets, but I didn't.

You need to be able to get the whole car off the ground to access the headers, but if you have liftbars or a quickjack you'll be set.

You could probably get by with going to a hardware store and getting a shorter length bolt for those lowers, but they are a little difficult to get in the right place with the headers in place.

storii

Thanks guys! If the upper shields alone can cover the coils (I'm assuming that includes coil 5 & 6), what do the lowers do?

ledbette

The uppers protect the coils from the cat heat. The lowers move the heat from where the headers connect to the block over the uppers. Without the lowers, you'll get more header heat. But, if you don't want to bother with the lowers, I think the uppers alone are much better than nothing.

storii

Thanks ledbette! Do you happen to have a picture of the shields installed in their respective places?