samk

At 65,ooo miles my Carrera is idling rough, but smooth sout while crusing---ONLY IN THE RAIN. Flashing CEL when acceleration and on the rest of the time on.
I checked codes and erased them on three seperate ocassions. The first was P0300, 301, 303. 305., the second was Po300 and 301. The third ocassion was 301. 300, 303. The car runs fine in the dry. 65,000 sservice is complete and no other symptons.

Macster

Coil packs.

Error codes are misfires. Light blinks because misfires feed unburned gas and too much of it to the converters which will burn the gas but overheat in the process. Overheating will damage the converters and automakers are on the hook for the converters for 7 to 8 years and 80K or more miles. So anything that puts the converters at risk gets flagged early and often.

Sincerely,

Macster.

samk

Does this mean all left side Coil Packs or all coil packs are bad???

yasuro

just replace all of them. seems like cheap insurance.

Macster

Misfires are appearing at cylnders of both banks: Cylinders 1 (P0301) and 3 (P0303) of bank #1 and cylinder 5 (P0305) of bank #2.

P0300 is a general misfire error code.

As poster yasuro suggested and I agree, replace all 6.

If you replace just 1, 3 and 5 now, you'll be in the engine compartment again shortly replacing 2, 4, and 6.

If plugs old and due for replacement might be a good time to change these as well, "while you are there".

Sincerely,

Macster.

samk

Thanks guys, and will do.

blinkwatt

You said it only happens in the rain.....I'd check for some type of leaks. If your coil paks were bad I would think they rain would not be a variable.

Torontoworker

Agree. I had one of the little O rings crimped that caused me a code. Again, as others have said - depending on mileage, I'd do the plugs if you have to go in there to look at the coils. Most of the time it's not the coil but the tubes (they crack with age) or the O rings. The tubes are cheap to do - the coil packs not so much. My wife hates the term, 'While I was in there..." as she knows I'm heating up the debt card when she hears that.

Macster

No. The rain is a variable and highlights the coil packs are the most likely suspects in the misfire source.

While climate dry and unchanging coil packs are fine. But with rain comes increased moisture in the air (of course) and all surfaces of car and engine exposed to outside air tend to collect moisture. It doesn't take much combined with the dust that is present to collect in coil pack cracks to affect the performance of the coil packs and cause misfires.

Or the engine's fine when started and driven in wet weather conditions but when it is put away road splash on the car evaporates from the heat and the high humidty in the confined area under the and its wheel wells and engine compartment can put moisture on the coil packs (and elsewhere for that matter).

Thus the next time the engine is started the misfires appear.

If the engine is run long enough and gotten hot enough the moisture can be driven from the coil packs. If the remaining solids are not too great the misfire can go away and stay away until the car washed or the wet weather returns.

Sincerely,

Macster.

samk

/Users/user/Desktop/IMG_0882 3.JPG
Coil packs were cracked and rusted and I replaced them and plugs.

samk

http://i300.photobucket.com/albums/n...8/IMG_0881.jpg
http://i300.photobucket.com/albums/n.../IMG_08793.jpg

samk

http://i300.photobucket.com/albums/n...8/DSC08130.jpg

samk

http://i300.photobucket.com/albums/n...8/IMG_0881.jpg

gota911

Sam,

I assume your baby is running smoothly again?



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samk

All is good and that no. 4 plug was a tough one. Easier than a 964 plug change though. Many thanks. P. S. Two coil packs out of 6 were still good. Also replaced mufflers with Porsche Tek.