944 Spark Plugs — Type, Gap & Replacement
The spark plugs for the 8-valve 944 — type and electrode gap, tightening torque, firing order, and the replacement procedure. Torque switches between N·m and ft·lb; the electrode gap is a fixed dimension in millimetres.
Difficulty: Easy1 min readApplies to: 944
Changing the plugs is one of the simplest jobs on the 944, but the type, gap and torque all matter on a DME-managed engine. These are the factory figures and the procedure. For a no-start or misfire, work through ignition system troubleshooting first; for the full car spec sheet see the 944 technical data.
Plug specification
| Figure | Value |
|---|---|
| Plug (Bosch) | WR 8 DS |
| Plug (Champion) | RN-10 GY |
| Electrode gap | 0.7 mm (+0.1 mm) |
| Tightening torque | 25 N·m18 ft·lb to 30 N·m22 ft·lb |
| Thread | M 14 × 1.25 |
| Firing order | 1-3-4-2 |
The plug caps are the without-booster-gap type — there is no series resistor gap inside them, so the suppression lives in the cap and lead. The DME controls ignition timing; there is nothing to set by hand.
Replacing the plugs
- Pull off the spark-plug caps — grip the cap, not the lead, so you do not pull the connector off the wire.
- Unscrew the plugs with a plug socket (the car's toolkit includes a plug wrench). Work on a cool engine to protect the aluminium head threads.
- Set the electrode gap on the new plugs to 0.7 mm before fitting, and give the plug threads a light coat of graphite grease.
- Start each plug by hand to avoid cross-threading, then tighten to 25 N·m18 ft·lb to 30 N·m22 ft·lb.
- Refit the caps in firing order 1-3-4-2 and check each is fully seated.
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