| Removal and Installation | | 21‐202 Socket, spark plugs | | | 21‐226 Pliers, spark plug connector | | Motometer compression pressure recorder, no. 623.000.1101 | | Connector for Motometer compression pressure recorder, no. 622.004.1005 | | `Never Seeze' | ESE‐M1244‐A | | Silicone grease | A960‐M1C171‐AA | Measure the compression pressure | |  | NOTE: The compression pressure should be checked at operating temperature. | 1. General remarks The exact determination of compression pressure depends on several factors, and therefore requires certain prerequisites. | | | | | NOTE: The central electric box (CJB) is located in the left‐hand footwell. | 2. Remove the fuel pump relay. | | | | NOTE: The engine will start, run for a few seconds and then stop. | 3. Start the engine. | | | 4. Remove the ignition coil cover. |  | CAUTION: Do not pull the cable when removing the spark plug connector. If necessary, remove the ignition cables from the ignition coil to avoid kinking the cable. Turn the spark plug connector slightly before removing to loosen the gasket. | | | CAUTION: Pull off the spark plug connectors in line with the spark plugs (for angled spark plug connectors use Special Tool 21‐226). | | | | 5. Pull off the spark plug connectors and remove the ignition coils. | | | 6. Remove the spark plugs. | | | 7. Measure the compression pressure Fit the connector and attach the compression pressure recorder. | | NOTE: Crank the starter motor until the indicator on the compression pressure recorder stops rising. | Carry out the measurement on each cylinder following the instructions supplied with the pressure recorder. | | | | | NOTE: Apply lubricant (ESE‐M1244‐A) to the spark plug threads. | 8. Fit the spark plugs. | | CAUTION: Use a blunt object (e.g. a plastic cable tie) to apply the silicone grease, to avoid damaging the spark plug connector gasket. | | | CAUTION: Push on the spark plug connectors, keeping them in line with the spark plugs. | | | NOTE: Coat the inside of the spark plug connector with silicone grease (A960‐M1C171‐AA) to a depth of 5‐10 mm. | | | | 9. Fit the ignition coils and push on the spark plug connectors. | | | 10. Fit the ignition coil cover. | | | 11. Insert the fuel pump relay into the CJB. | |
