Cylinder misfires...

When I started the car this morning, the car idled rough then the check engine light came on and stayed on. It is not flashing, just on steady. I turned the car off...waited a bit and restarted. The idle was rough then settled into a normal idle. Took it out, drove around and it ran fine - Smooth idle, normal performance. Car had about 1/4 tank of gas so I filled up with the top shelf BP gas. Now the car is running smooth, but the check engine light is always on.

So my questions are:
1. this sound familiar to anyone? Do I need to take it to a mechanic?
2. Is there any way to reset the warning light other than disconnecting and reconnecting the battery?

So my questions are:
1A. this sound familiar to anyone? - yes, it is sounds similar to when one of my oxygen sensors went bad on my 986.

1.B Do I need to take it to a mechanic? Not yet, use an OBD Reader and read the specific Porsche error code. If it is an oxygen sensor you can do it easy enough yourself.

2. Is there any way to reset the warning light other than disconnecting and reconnecting the battery? No, you will have to take it to the dealership or use a Durametric Diagnostic Cable and software to clear the message.

"Bart, with $10,000, we'd be millionaires! We could buy all kinds of useful things like...love!"

Certainly on 986s a plain code reader can reset the CEL. I'd suspect the 987 is the same and the ~$50-100 investment in a code reader would pay off many times on many cars...has for me.

of failures, from a bad AOS to a bad MAF to bad gas to bad plugs/coils to even a bad VarioCam solenoid & actuator. And there may be more failure modes but these (save the bad plugs/coils and bad gas one -- I've never had any bad gas in my cars) are the one's my 02 has had.

You really need to have the error code read and be sure to write it down. Depending upon the code you might be ok to clear it or have it cleared and drive the car some and see what happens. Or the error code could be the early warning signs of more serious problems that if left unaddressed could have the engine in deeper trouble.

Disconnecting the battery to clear the error codes is the technique of last resort. An OBD2 code reader/data viewer is very inexpensive and I highly recommend one hvae one on hand for just such these occasions.

Sincerely,

MarcW.

... especially on a cold start the ECU may get mixed messages if the secondary air pump is slow to respond or you have a bit of oil in the mix.
The computer will try to compensate making for a rough idle until it realizes that the issue is gone. The CEL is triggered.
If this is the case the CEL will eventually turn itself off after several cycles.
But, it's best to be sure of what triggered the rough idle by having the error coded read, as most have suggested.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

I went and invested in an OBD2 reader. There were 2 codes. PO306 (Cylinder 6 misfire) and PO306 "pending" (Same cylinder... but the error was still "maturing")

Since that one incident, other than about 20 seconds of rough idle its been running smooth. I cleared the codes and will keep watching. I suspect if they return I will run it to a mechanic.

Speaking of mechanics, I live is West Chester PA a suburb west of Philadelphia. Bought the car at Porsche of the Main Line. Now that I am out of warranty (67k), I would love to find a trustworthy mechanic nearby. Anyone with experience in the Philly area with a good Porsche shop?

round I would not be surprised.

Sorry, but I can't make any recommendation for an indy shop to which you can take your car. I still take my out of warranty cars to a nearby dealer for service and repair. In my area the indy shops charge about the same as the dealer.

But I trust the techs at the dealership(s) where I take my cars and the dealers offer much better waiting room and shuttle service than the indy shops.

Sincerely,

MarcW.

Quote
MarcW
round I would not be surprised.

Sorry, but I can't make any recommendation for an indy shop to which you can take your car. I still take my out of warranty cars to a nearby dealer for service and repair. In my area the indy shops charge about the same as the dealer.

But I trust the techs at the dealership(s) where I take my cars and the dealers offer much better waiting room and shuttle service than the indy shops.

Sincerely,

MarcW.

Marc,

I'm in the next town south of you, Chadds Ford. Dougherty Automotive is a local shop that works on Porsche and other exotic cars. They are really good at what they do.....Located right off of Matlack St. and about 2 buildings before you get to the driving range. Bill is the owner..

I hope to get my car out soon. Bought it in mid January and it has been sitting in my garage waiting for the roads to clear up.

One last thing before I forget, Saturday mornings, weather permitting, there is a great group of cars (and owners) who meet for the West Chester Cars and Coffee. Usually starts around 830am or so. Lots of Porsche (old and new), Vipers,Ferraris,Lotus, etc. It's a lot of fun to compare notes and check out all the different cars.

John



Edited 1 time(s). Last edit at 02/13/2011 12:00PM by SeaNile. (view changes)

John,

Where do you meet in West Chester for the Cars and Coffee sessions?

Bill

John,
You probably meant that last part for me. Where does the "West Chester Cars and Coffee" group meet?

Regards,
Chip

Quote
cweldon978
John,
You probably meant that last part for me. Where does the "West Chester Cars and Coffee" group meet?

Regards,
Chip

Chip,

I did mean to reply to you...

The C&C as they call it meets on every Saturday am around 8-9 and often goes till after 10 with a drive to follow. Most of the talk about this is on www.ferrarichat.com in the mid atlantic section. it's not hard to figure out, if the weather is good and the roads are clean cars will be there. It's a great turn out in the summer with well over 20 cars. The location is the Dilworthtown Starbucks (Rt. 202 and Dilworthtown Rd., across the street from Enzo's and the relatively new WaWa) and the parking is right by the Giant Supermarket. It's a lot of fun and there are always really cool cars ranging from old MG's to a Stryker, Scuderia, 355's and an older Lambo, Callaway Vette and a Viper or two with some really cool old 911's and a few newer GT3 versions as well.

I'm only about 4 miles from it so I try to go as often as I can.

John

... can be a bad coil and in many cases a loose connector on the coil itself.
Unplug and reconnect #6, just to make sure it's making good contact.
Erase the error code and see if it happens again. If it does I'd suspect the coil pack.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Pedro,
Thanks for the info. I just cleared the codes and want to see If i get a recurrance. I have a couple followups:

1. The original motor was an IMS victin. Porsche put in a rectory reman motor at 44k (@25K miles ago). Do you know if replacement motors from Porsche include plugs coils etc etc? If so, then all these parts have only 25k on them.

2. Is the coil something easy to get to? Are there instructions posted anywhere that would guide me as I look to unplug and reconnect # 6? I've read that #6 is on the passenger side, closest to the front.

Coil replacement is a piece of cake. Look up Pedro's site for changing spark plugs as you remove the coil pack prior to removing the plug.

Bottom line....
Remove rear wheel on offending side.
Remove access panel in wheel well.
uplug electrical connector at the coil you want to change.
remove coil with socket set (8mm IIRC).
Replace coil
plug connector into coil pack
Replace access panel
Replace wheel.

Feel like a real mechanic!

dghii
2000 Boxster S 6speed 112k miles

The Boxster engine cylinder locations are:

^ Front of car ^

Cylinders #4 #1

Cylinders #5 #2

Cylinders #6 #3