2006 C4S multiple cylinder misfire and check engine
#1
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New to the forum and relatively new Porsche owner. 5 months now and until now has been fantastic. Have enjoyed reading all the information here. Having an issue so i thought i would post . Just had oil changed at dealer last week and week later on way home check engine light starts flashing and running very rough with lack of power. pulled over and had it towed to dealer. Dealer say says misfire fault multiple cylinders and need to check coils and plugs. They say coils are cracked and plugs and coils need to be replaced. Car was running perfectly before and just seems strange that multiple cylinders would at once start misfiring. I read some posts that say i'ts possible; but wanted to ask anyway. Car had PPI at dealer at purchase and was CPO'd in 2011. No smoke, no oil leak, no nothing. just all of a sudden misfires. had clicked the PSE button about two minutes before it all happened.
been without the car now for two days. Have a Hyundai rental. I miss the porsche:
been without the car now for two days. Have a Hyundai rental. I miss the porsche:
#2
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Cracked coil packs are common especially on a car that sees lots of rain or winter weather and is about 10 years old like yours. The car often runs fine but start misfiring when wet from rain or an car wash. Since your car is a 2006 it's probably time to replace them. Usually it's just one cylinder misfiring, whichever coil pack is cracked the most. The others usually show signs of cracking but don't necessarily misfire.
Multiple cylinders misfiring at the same time could be the engine got really wet and the symptoms showed up. But if they are all the same bank, say cylinders 4, 5 & 6, than it might be the crank position sensor instead. A few cylinders in both banks is usually not the position sensor.
So it's a reasonable diagnosis from your dealer. It's likely the cause, maybe not, but they certainly would be on my list to swap out due to age anyway.
Multiple cylinders misfiring at the same time could be the engine got really wet and the symptoms showed up. But if they are all the same bank, say cylinders 4, 5 & 6, than it might be the crank position sensor instead. A few cylinders in both banks is usually not the position sensor.
So it's a reasonable diagnosis from your dealer. It's likely the cause, maybe not, but they certainly would be on my list to swap out due to age anyway.
#3
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I would agree with the dealer on this. I have an 07 that had a similar problem - it would stumble a little when pulling away from a start - like at a stoplight. After a short while I got a CEL. The dealer said coil packs so I replaced them (and plugs) myself. No more issues. Here is one of the packs I removed. No mystery here.
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#4
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Thanks for the input on this. Makes me feel a little better. Just seemed weird that it could go from running perfect to multiple misfires at once. Dealer says it should be out of shop on Monday; if no other problems. Replacing plugs and coils.
#5
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Got the car back today. They showed me my coils- looked very similar to Chip's. cracked, expanded and a mess. Cars runs perfect again. $1,250 though....