Volkswagen Golf: 1.8T Ignition Coil Pack Failure (All Four Cylinders)

Early pencil-type ignition coil packs used in AUM and AUQ 1.8 turbo engines suffer thermal breakdown of internal windings, causing individual cylinders to misfire. All four coils typically fail within a short window once degradation begins. VW issued an updated blue-cap coil design but many NZ examples still carry original units after 20+ years. Failure is accelerated by oil contamination from a leaking cam cover gasket.

• Engine misfire or stumble under acceleration
• Check engine light with P0300-P0304 misfire codes
• Rough idle that partially clears at higher revs
• Single cylinder cutting out intermittently at operating temperature

1. 1

   Pull each coil pack and inspect the casing for heat cracks and oil contamination.

2. 2

   Verify whether coils carry the updated VW blue-cap part number.

3. 3

   If a workshop inspection is possible: Connect an OBD scanner and check for any stored misfire codes.

4. 4

   Start the engine cold and load-test by driving uphill in a high gear to provoke misfires.

Parts involved: Ignition coil.

$320 to $650 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Have the coil packs been replaced with the updated VW blue-cap redesign?”
• “Has the car shown any misfire or check engine light history?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.