Boost Pressure
CAUTION:
This operation requires the use of a chassis dynamometer to safely test components. If dynamometer is not available, testing can simulated with a road test and the correct equipment arrangement.
- To test turbocharging system, use Pressure Gauge (VW 1397). Gauge is equipped with a valve which locks pressure measurement when closed.
- Attach gauge to vacuum advance at distributor, using "T" fitting supplied with gauge. Ensure vacuum advance unit and charcoal canister purge valve are free of leaks. Use hose clamps at all connections to avoid 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 shut-off valve. Record reading.NOTE: Testing should not exceed 10 seconds at full boost.
- Boost pressure readings will vary with temperature. Compare results with readings in BOOST PRESSURE SPECIFICATIONS table.
- If boost pressure is incorrect, replace wastegate as a testing measure and retest. If boost pressure is still incorrect, 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) |