Another cause of backfires can be ...

03 Boxster S with about 58k miles. Twice within the last two week, when I started my car cold, within seconds, there will be a really loud, almost machine gun like popping noise coming from behind my head. The first time, there was a battery light and a oil pressure light that turned on but when I shut the car off and restarted it, the car sounded normal, all the lights were off, and drove just fine. Today, the car once again made the same machine gun like popping noise from I'm assuming the engine but no CEL or any other dash lights. When I turned the car off and restarted, everything seemed normal. Is this my car misfiring really badly? I would say I was hearing anywhere from 4-6 pops a second when this was occurring. The only thing I can think of is that sometimes when I'm in a rush, I just put the key in and turn it really fast versus waiting 5 seconds or so for the oil level to be checked, but I can't imagine how that would make a difference. Anybody have any suggestions? I never noticed this before. Just had my clutch redone at the dealer right before this started to happen and they didn't find anything else wrong with the car at that time.



Andrew

Try checking for pending codes (that wouldn't necessarily trigger a CEL).

Most likely causes are bad gas or a cracked ignition coil.

... An air leak in the intake
Could be that your shop didn't make sure that the throttle body was perfectly seated in the rubber sleeve

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

There is no need to touch the intake when replacing the clutch. Unless they did other work not mentioned...

... but you never know.
I don't believe in coincidences.
When dropping the tranny the intake tube could have been dislodged.
If the car ran well before visiting the shop and he didn't put any bad gas in it, something could have been changed while there.
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