kino1161

I changed my coils and plugs on my 08 GTS. I changed them because the truck had abut 80K miles and I didn't know if they had been changed or not. See pics. Can anyone see anything wrong with the ones I took out of the vehicle? The truck was running fine prior to replacing them. Should I keep the ones I removed from the vehicle as a back up? I couldn't find any cracks or tears in the coils, either.

nodoors

Need a better angle and closer shot of the plugs to read them well. I would save one or two coils just in case you get in a pinch one day on a road trip.

Andy E.

Why replace your coils if they're functioning well? The newer generation coils are less prone to failure than the older ones. With improved sealant technologies, they rarely show a visible crack like the Gen I coils used to.

One of my coils was failing intermittently due to a variance in temperature and not in humidity. Using a standard OBD-II reader, it was determined that coil no.4 was the problem. Spraying a very fine mist of water directly above the culprit coil did not yield any immediate change in performance however, its replacement did.

As nodoors stated, the condition of your plugs are hard to read; given the angle of the photo. Hopefully you numbered them so that you can refer to a potential problem within a given cylinder.

deilenberger

It looks to me that the plugs have a rounded over center electrode. When new - the center electrode has a sharp 90 degree angle on the end. Since all the plugs look rather uniform as far as the ceramic color - I think there are no problems to be concerned about. I'd toss them. I always say that, but usually ferret one or two away "just in case" - and eventually throw them out when I sell the car.

ScootCherHienie

Those plugs have been in your car for 80,000 miles... VERY obvious from black tips, browning along edges of the insulator and the amount of "stuff" in the threads. That said, these new-style plugs are usually fine for 100,000 miles in almost any engine unless there has been a long term problem like running too lean. Carry a few of your old coils in the car (along with your OBDII code reader so you can determine which cylinder is having trouble... and bring some means of decoding the OBD codes also (might be on your phone, and some OBD code readers are Bluetooth and work with free or pay versions of Torque app for mobile phones) and put the rest in a sealed bag in your garage or other storage area for possible future needs. I would clean-up the coils before storing them making sure they are very dry before being put away... and cean with water after using any soapy cleaners to remove dirt so no soap or ammonia (Windex) is left behind on coil surfaces.

kino1161

Thanks, all, for your comments. @AndyE, Honestly, I replaced them from pure ignorance. I am new to Porsche and I read on the forum where people were saying to replace coils and plugs and I had almost 80K miles on the truck.

ScootCherHienie

SOMETIMES (wish it was more often!) components are actually improved over time. What applied to 955 coils (up to '07) may not apply to 957 and later coils and even the 955 coils may have been improved by the time they needed to be replaced (maybe, no guarantee though). Anything you read about a model different than the one you have probably (but MIGHT) apply to your model as well... never assume.

The downside is that sometimes manufacturers never revise a poorly designed part.

deilenberger

The original V8 coils from the 955 are up to revision 20 something now. They seem to keep trying.
That manufacturer have a 3-letter name? Like BMW? Only once did I see them actually revise the design of a common failure part to improve it. It's the reason a Porsche now lives in the same garage that had multiple BMWs in it for 30 some years.

Mostly BMW just keeps selling the same piece of crap part, like fuel-level strips on the bikes - from 2005-2014 they used a new high-tech no moving parts sensor. I went through 9 of them on my '07 bike, and so far 3 on my '12 bike. And they still provide the exact same POS part - for free - 12 year warranty on the part.

ScootCherHienie

BMW certainly has their problems... window lift mechanisms for example... not sure how far back this goes, but they sucked in my 2000 3-series and the ones the dealer sells today are just as failure prone as the originals. One of them failed with just 15,000 miles on the car... drivers door... broke after paying the last toll we would have to pay on the way to Florida from NY and each door broke the lift mech fail with some doors failing 2 times. Rock Auto is selling one for 1/3 the price of the dealer part that has a ball bearing on one of the pulleys that they claim is "the fix"... but my fix has been to intall stubby screws in 2 existing holes around the cover where the cable wraps around the plastic hub. Installing new rubber in the window frames helps too, but as soon as it loses it's original non-sticky surface, the lifts start breaking again. Dry lube and powder on the rubber haven't helped either (by reducing friction between glass and rubber so the lift mech doesn't have to work so hard). I've replaced them on X5s too. How long are they allowed to make crap parts? But BMW is FAR from the only company that seems to think once a part is out there, no matter how bad, it's never updated.

deilenberger

It was once explained to me by someone quite familiar with the BMW culture why this is so. BMW company people are very polite and loyal. The engineers all want and give respect to and from other engineers. For an engineer to point at a design from another engineer and say that it is flawed is insulting to the engineer that designed the part. Even implying the part could be improved on means they are telling the other engineer that their work is better, or the designing engineers work is substandard.

That is NOT acceptable.

So - in order for a part to be changed in design (and a problem fixed) - they have to wait until the engineer who originally designed something to retire. Only then can they change the design.

As far as the window lift mechanisms - surprisingly I only had one fail on me (out of about 10 or 12 different BMW cars I owned) - but that was on a 1991 5-series, and it was a common failure (of a tracking wheel that was made of nylon that simply fell apart and was not replaceable as a part - you had to replace the entire lift mechanism and motor which was riveted to the assembly.)

It was a combination of complexity and ****-poor (tech term) design that resulted in frequent failures. And the one that replaced it was absolutely identical.

BMW seems to excel in this sort of thing. Porsche does seem to actually improve on the commonly occurring failure designs even after the vehicle is out of production.

Andy E.

This is a perfect example of Swabian vs Bavarian methodology. BMW's repeated failures with the N63 engine is a good example of this shortcoming.