Boost Pressure
- To check boost pressure of turbocharger system, use Pressure Gauge (VW 1397). Gauge is equipped with a valve to lock pressure measurement.CAUTION: This operation requires the use of a chassis dynamometer to safely test components. If dynamometer is not available, testing can be simulated with a road test.
- Attach gauge to vacuum advance at distributor, using "T" fitting supplied with gauge. Ensure vacuum advance unit and charcoal canister purge valve are not leaking. Use hose clamps at all connections to prevent low readings.
- Warm engine until oil temperature is above 176°F (80°C). Accelerate engine to 4000 RPM in second gear with automatic transmission (third gear on manual transmission). Hold vehicle speed constant and close gauge shutoff valve. Record reading.NOTE: Testing should NOT exceed 10 seconds at full boost.
- Boost pressure readings will vary with temperature. Compare results with boost pressure values in the BOOST PRESSURE SPECIFICATIONS table.
- If boost pressure readings are not as specified in table, replace wastegate and retest. If readings are still out of specifications, replace turbocharger.
BOOST PRESSURE SPECIFICATIONS
| Ambient Temperature | psi (kg/cm2 ) |
|---|---|
| -4°F (-20°C) | 6.2-6.9 (.43-.49) |
| 14°F (-10°C) | 6.0-6.8 (.42-.48) |
| 32°F (0°C) | 5.9-6.6 (.41-.47) |
| 50°F (10°C) | 5.7-6.5 (.40-.46) |
| 68°F (20°C) | 5.6-6.3 (.39-.45) |
| 86°F (30°C) | 5.3-6.2 (.37-.44) |