Coil Packs on a 997

[AlexH997]

I have a 997.1 carrera s

my understanding is that there are 6 coil packs.

Can you just replace those which are broken or should you replace all of them? what will i experience if they have failed?

What's the cost of these? my car is due a spark plug and service in February 2014 and i was wondering whether they'll need replacing.

thanks all

[sidicks]

AlexH997 said:

I have a 997.1 carrera s

my understanding is that there are 6 coil packs.

Can you just replace those which are broken or should you replace all of them? what will i experience if they have failed?

What's the cost of these? my car is due a spark plug and service in February 2014 and i was wondering whether they'll need replacing.

thanks all

When my car was at Exeter OPC recently, they replaced the coils to the 'EM10' version under warranty - apparently the previous version can crack........

[Rockster]

AlexH997 said:

I have a 997.1 carrera s

my understanding is that there are 6 coil packs.

Can you just replace those which are broken or should you replace all of them? what will i experience if they have failed?

What's the cost of these? my car is due a spark plug and service in February 2014 and i was wondering whether they'll need replacing.

thanks all

Absent a CEL with associated misfires error codes the coils do not have to be replaced automatically.

When the plugs are done the tech should examine the coils and take into account their condition (which is impacted by the weather/climate conditions where you live and drive: wet/damp weather, snow/ice and salted roads: bad on coils) and mileage.

If one is bad and the rest look ok and are not *too* old perhaps the tech would change just the bad one. Or he might advise you to change all 3 on that bank -- the shoulder side bank generally gets the worst of it from water splash -- or perhaps given what I said above advise you to replace all 6. While some owners get good mileage out of the coils some do not.

Of course you can elect to replace all 6 if you are so inclined. Many do, many consider coils a wear item that should or must be replaced periodically regardless.

I live in an area that produces long lived coils and would therefore wait for some indication the coils need to be replaced. If I lived in an area that had harsher weather that was notorious for causing accelerated coil degradation I'd consider replacing them every so often. Maybe as often as every plug change.

Your call though of course listen to what you trusted tech has to say.

[OggyDJ]

Sure can :-



(Not my picture, just borrowed it from T'internet)

Hi Alex,

As per picture, each plug has its own coil and over time (and many heat cycles / general decay), they can split.

If one has split, it's more than likely others have too (although I seem to remember some are more vulnerable than others ??).

Depending on severity of the split and amount of moisture entering the coil, you can either get serious misfire / "check engine" warning light or.....it just feels down on power / slight misfire & jerkiness low-down. This latter case is exactly what I had on my 997.1 C2S.

Had all six coils changed (with plugs) and it felt like a different car ! Loads smoother, much more willing to pull from low-down and no misfire or jerkiness. All modern petrol cars can suffer same fate however the Flat 6 is more prone to it due to plugs (and hence coils) being closer to the road surface & consequently exposure to the elements.

Can't remember the price I'm afraid....wasn't mega bucks though as had mine done at a local Indy.

(P.s. this is general idea as I understand it....I ain't no mechanic !!)

[AlexH997]

brill thanks fellas thats very useful

[AlexH997]

Just one thought, if a coil pack is gone what damage can you do to the engine if any?

[Pope]

Misfires lead to unburnt fuel in the exhaust which leads to Catalyst damage (a flashing check light means exactly that 'misfire damaging to Cat' - a solid check engine light denotes a fault in the general DME system) effects will be worse in an intermittent fault scenario (a consistent fault will be detected far quicker and will result in the DME switching off the injector on the affected cylinder) -In short if the light is flashing get the car recovered as further costs may result

[Rockster]

AlexH997 said:

Just one thought, if a coil pack is gone what damage can you do to the engine if any?

Worst case is as Pope said.

In less severe cases the damage arises from incomplete combustion which wastes gasoline, affects the car's driveability and likely reduces the driver's enjoyment of the car, and accelerates the contamination of the oil. Unburned gasoline in the chamber condenses on the cooler parts of the chamber. This increases deposits which can affect combustion and further degrade the engine's operation. The gasoline condenses on the cylinder walls dilutes the oil film there and when the piston/rings rise again in the cylinder they can do so with less than optimal oiling present which can result in an increase in cylinder, piston and ring wear.

Over time the above can be a worse case scenario. A converter is relatively cheap and easy to replace. An engine with one more worn out cylinders is not so cheap and easy to replace.

[Magic919]

A decent garage will advise if they need replacing. Was only about £40 each when I did some on a 996. Can't be much different.

[AlexH997]

Thanks chaps that's really useful

I don't get any check engine light but I sometimes find when I start my car maybe an hour after it was last used when the engine is still warm the car needs to turn over a few times before the engine starts up. Doesn't happen when it's cold.

Anything to be concerned about