Vauxhall Workshop Service and Repair Manuals > Astra > J Engine and Engine Aggregates | Diesel Engine | General | Repair Instructions

Compression, Check

Use compression recorder with a measuring range up to 17.5 bar/ 253.8 psi.

The compression is checked with the engine at operating temperature (coolant approx. 80 °C/176 °F and oil > 70 °C/160 °F).

If oil pressure is suspected of being too high (hydraulic valve lash adjusters), check oil pressure before measuring compression.

Remove all spark plugs.

On DOHC engine use Plug Spanner KM-194.

Object Number: 2374580 Size: DEFAULT

Press rubber cone of compression recorder into spark plug bore of cylinder to be tested (on DOHC engine use adapter).

Note: On fuel injection engine remove fuel pump retainer and thus break off fuel flow.

Engage starter for approx. 4 seconds with throttle valve fully open.

Engine speed should be at least 300 min^-¹.

Check all cylinders in this way.

Before checking each cylinder, reposition test sheet in compression recorder.

Difference in pressure from cylinder to cylinder must not be more than 1 bar/14.5 lbf/in2.

Install spark plugs with Torque Limiter (17 57 060 - 90 166 052).

On DOHC engine use Plug Spanner KM-194.

Torque: 20 Nm/14.75 lbf. ft.

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