Testing compression pressure, hazard warnings - RA01001200100X(01-0100)
WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.
Operation no. of the operation texts and work units or standard texts and flat rates
Model 129
Risk of injury when hood opened and engine running.
The engine is equipped with an electronic ignition system. Because of the high ignition voltage, it is extremely dangerous to touch any of the ignition components (ignition coil, distributor, ignition cables, spark plug connectors, test socket) when
- the engine is running.
- the engine is started.
- the key in the steering lock is in position 2 and the engine is being cranked by hand.
the engine is being cranked by hand.
Pay attention to notes regarding working on breakerless transistorized ignition system
| Engine | warm up to normal operating temperature. |
| Spark plugs | remove, install (15-1031) . |
| Engine | crank several times to eliminate residues and soot (01-0110) by pressing at contact handle of compression pressure recorder (01) in closed throttle position and parking brake applied. |
| Diagram sheet (03) | insert into compression pressure recorder (01). |
| Compression pressure recorder (01) with | press in into spark |
| adapter (02) and sealing cone (04) | plug hole of relevant cylinder. |
| Model 140: Throttle valves | open fully by means of accelerator pedal. |
| Engine | crank with starter approx. 8 revolutions (01-0110) . |
| All cylinders | test in the same manner. |
| Spark plug recesses | blow clean with compressed air. |
| Fault memory of DI control module | read (see Diagnosis Manual Engine |
| (N1/4 and N1/5) | Volume 2, Index 0). |
| If minimum compression pressure not achieved | test cylinders for leaks (01-0150) . |
NOTE:
Model 129: Test cylinder 12 with 90° adapter (05) because of fuel lines.
Model 140: Test cylinders 6 and 12 with 90° adapter (05).
TEST DATA
| Compression ratio | 10 - 0.4 | (8.0) (1) | |||
| Test data for engine at operating temp. | Pressure in bar | ||||
| Compression pressure at | Normal compression Fuel-optimized | min. 10 | max. 14 | ||
| min. 6 | max. 10 | ||||
| Perm. difference between individual cylinders | max. | 1.5 | |||
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