Stalled...Erp

[threpwood]

The mechanic said that there is a high probability that the 4th cylinder failed They have checked everything including spark plug, etc and didn't find any problems.

Can anybody explain why the 4th cylinder failed and if it is fixable (I mean do I need to start looking for new engine?)

Does this statement below apply for boxster (taken from wikipedia):

During use, the cylinder is subject to wear from the rubbing action of the piston rings and piston skirt. This is minimized by the thin oil film which coats the cylinder walls, but eventually the cylinder becomes worn and slightly oval in shape, usually necessitating a rebore to an oversize diameter and the fitting of new, oversize pistons. The cylinder does not wear above the highest point reached by the top compression ring of the piston, which can result in a detectable ridge.

If an engine is only operated at low rpm for its early life (e.g. in a gently driven automobile) then abruptly used in the higher rpm range (e.g. by a new owner), the slight stretching of the connecting rods at high speed can enable the top compression ring to contact the wear ridge, breaking the ring. For this reason it is important that all engines, once initially run-in, are occasionally "exercised" through their full speed range to develop a tapered wear profile rather than a sharp ridge.

[MNBoxster]

Hi,

That's a pretty drastic diagnosis. What code did they receive - P0300, P0304 or P1316? These are the only relevant codes for EOBD software which your car has, though there a misfire can be consequential of other causes as well.

Schnell describes only one way for a misfire to occur. There are many other ways this can happen such as Fuel Delivery, O² Sensor and/or MAF issues - causing the Engine to run Rich or Lean, Electrical Issues such as bad CoilPak, Wiring, etc., even water entering the engine can cause it - did you wash the car or drive in rain recently?

I'd be very surprised if their diagnosis holds up. Just because they're Porsche Mechanics doesn't make them immune to mistakes. For a Wear Ridge to develop in the cylinder, such as you describe, you'd have to have a fairly high mileage engine. The Locasil lined cylinders are not prone to this type of wear.

As I said, long distance diagnosis is difficult at best. But, your mechanic's diagnosis would be very rare and unusual. So much so, that my initial inclination is to distrust it without further information, such as the actual codes they are getting. Of course, I may be wrong and they could be right we'll have to wait and see. Good Luck!...

Happy Motoring!... Jim'99