FAQ
TL;DR: AZJ 2.0 misfire on wet/cold starts was fixed by swapping the coil pack; “20 minutes and that’s it.” — an expert said. [Elektroda, sulof1601, post #16653004]
Why it matters: This FAQ helps VW Golf 4 AZJ owners diagnose jerks, idle wobble, and cold-start power loss quickly and cheaply.
Quick Facts
- Vehicle/engine: VW Golf 4, 2.0 AZJ, 115 hp; symptoms worsen on damp or cold starts. [Elektroda, ondrei, post #16652930]
- OEM coil brand noted by users: TEMIC (factory fit on comparable 2.0). [Elektroda, grala1, post #16653774]
- Recommended replacement brands from thread: Beru or NGK. [Elektroda, sulof1601, post #16653039]
- Access on AZJ: remove secondary air pump; coil uses 3 Torx screws. [Elektroda, ondrei, post #16659423]
- Swap time: Approx. 20–30 minutes with basic tools. [Elektroda, ondrei, post #16654938]
What common symptoms point to a failing coil on the AZJ 2.0?
Slight jerking after start on damp/cold days, weak acceleration until about 60°C, and a gentle idle wobble. These symptoms persisted regardless of fuel, then disappeared as the engine warmed. That pattern strongly implicates the coil pack on this engine. [Elektroda, ondrei, post #16652930]
Is the ignition module built into the coil on this engine?
Yes. The AZJ setup integrates the ignition module into the coil assembly, so the part is often listed as a coil or coil module interchangeably. [Elektroda, sulof1601, post #16653081]
Which coil brands did owners use or recommend?
Thread experts advised Beru or NGK. The reporting owner installed an NGK unit and confirmed improved performance after replacement. “Beru or NGK.” [Elektroda, sulof1601, post #16653039]
How long does it take to replace the coil?
Expect about 20 minutes if you know the layout, using basic hand tools. One poster reported a 20–30 minute swap during their driveway repair. “20 minutes and that’s it.” [Elektroda, sulof1601, post #16653004]
Do I need to remove the secondary air pump to reach the coil on AZJ?
Yes. The owner walkthrough shows removing the secondary air pump first for access, then the coil with three Torx screws. Label HV leads before removal. [Elektroda, ondrei, post #16659423]
What’s the quick driveway test for bad HV wires versus a bad coil?
Mist the HV wires lightly with water while avoiding the coil. If the engine stumbles or arcs appear, suspect the HV leads. If not, the coil pack may be at fault. [Elektroda, grala1, post #16653774]
What was the real-world fix outcome after coil replacement?
A cracked original TEMIC coil was replaced with NGK. The car then ran smoothly on a humid, cool morning, and acceleration jerk disappeared. [Elektroda, ondrei, post #16654938]
Which screws secure the AZJ coil, and how many are there?
The coil is held by three Torx screws on the AZJ. Access improves after removing the secondary air pump as described by the owner. [Elektroda, ondrei, post #16659423]
Any edge cases or model differences to watch for?
Yes. On the 2.0 AQY, access to the coil screws requires removing the secondary air pump. Layout differs from AZJ due to intake variations. [Elektroda, grala1, post #16653774]
Should I label the HV cables before pulling them off the coil?
Yes. The owner labeled each HV lead before removal to avoid cross-connection during reassembly. It kept the job clean and quick. [Elektroda, ondrei, post #16659423]
My temp won’t reach 90°C—could the thermostat cause misfires?
In the thread, a low temp reading coexisted with misfires, but the misfire resolved after coil replacement. Treat thermostat as a separate issue from the ignition fault. [Elektroda, ondrei, post #16652930]
What was the factory coil brand observed on this engine family?
Users reported the original coil as TEMIC on a comparable 2.0, aligning with observations from the thread’s teardown. “The original is a TEMIC coil.” [Elektroda, grala1, post #16653774]
How do I pick a replacement coil if catalogs list only “ignition coil”?
Choose a unit specified for the AZJ engine code. The module is integrated, so listings may say “coil” or “coil module.” Brands cited were Beru and NGK. [Elektroda, sulof1601, post #16653081]
What are the telltale signs the coil itself is physically bad?
A visual crack on the coil body is a red flag. The reporting owner found a slight crack underneath; replacing it eliminated the jerking. [Elektroda, ondrei, post #16654938]
Can wet weather alone trigger these AZJ misfires?
Yes. The owner saw consistent jerking and power loss on damp or cold starts, clearing as temperature rose. That weather-linked pattern implicates ignition components. [Elektroda, ondrei, post #16652930]
How do I replace the AZJ coil? (3-step How-To)
- Remove secondary air pump for access; unplug its connector. Label each HV cable.
- Undo the three Torx screws; detach the coil connector.
- Fit the new coil, reconnect HV leads and plug; refit the pump. [Elektroda, ondrei, post #16659423]
