
The 99760210405 is the individual coil module used on the Porsche M96 and M97 M-series engines in many 986/996/987/early 997 cars. Normally should be replaced as a set of six coils (one per cylinder)
Why these coils should be replaced
Age / thermal breakdown: coils are exposed to heat cycles and can develop internal insulation breakdown or hairline cracks in the housing. Over time this causes weak or leaking high voltage and intermittent sparks.
Misfire symptoms: a failing coil will cause single-cylinder misfires (P030x codes), rough idle, reduced power, increased fuel consumption and catalytic converter heating/damage if left. These are the most common reasons owners replace coils.
Carbon tracking / cracking: visible cracks or carbon tracking on the coil boot can provide a leakage path for spark, reducing performance and causing intermittent faults.
Connector / wiring issues: corroded or loose coil connectors can mimic coil failures; inspect connectors when replacing coils.
Fits:
Porsche 996 3.6L Inc C2 / C4 / C4S
Porsche 986 Boxster 2.7L / 3.2L 2003>>
Porsche 996 GT3 MKI
Porsche 996 GT3 MKII
Porsche 996 Turbo
Porsche 987 Boxster 2.7L / 3.2L
Porsche 987C Cayman 2.7L / 3.4L
Porsche 997 3.6L, 3.8L / 997 GT3
Does not come with securing bolts.
2 required per coil, please order separately (part number 90006708901).
Common issues reported in practice
One or more cylinders misfire when the engine is hot but behave quite normally when cold (typical of internal coil failure or heat-sensitive cracks). Cracked coil housings on Boxster/996 cars, owners often replace the entire set for reliability. After a spark plug change, misfires appear because weakened coils can fail once higher-voltage plugs are installed; this is a frequently reported pattern.How to diagnose (practical steps)
Read codes: P0300 / P0301–P0306 point to misfires; note which cylinder is affected.Swap test: swap the suspected coil with another cylinder’s coil — if the misfire follows the coil, the coil is bad. (Common, quick field test used by owners.)Measure resistance: check primary and secondary coil resistances at ~20°C and compare to the ranges above.Visual inspection: look for cracks, carbon tracking, oil ingress, or damaged boots/connectors.Oscilloscope / HV probe: for deeper diagnosis a scope or HV probe can show spark energy, but most DIY diagnostics use swap + resistance checks.Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760210405
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 997 Carrera 2 3.6L 2005>>
- Porsche 997 Carrera 2S 3.8L 2005>>
- Porsche 997 Carrera 4 3.6L 2005>>
- Porsche 997 Carrera 4S 3.8L 2005>>
- Porsche 997 TURBO 2007>>
- Porsche 997 GT3 2007>>
- Porsche 997 GT2 2007>>
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08