For 1990-2009 cars only
- Disconnect the PCV hose.
- Start the engine.
- Check for vacuum at the hose. If there is no vacuum, check for a plugged hose or manifold port. Check for a hose that collapses when blocked (vacuum applied). Replace the plugged or the deteriorated hoses.
- Allow the engine to idle at normal operating temperature.
- Remove the engine oil dipstick and install a vacuum gage in the dipstick tube.
- Block off the PCV system fresh air intake passage.
- Run the engine at 1500 RPM for 30 seconds, then read the vacuum gage while the engine is running at 1500 RPM.
| • | If vacuum is present, this indicates that the crankcase ventilation system is functioning properly. |
| • | If no vacuum is indicated, the engine may not be sealed and is drawing in outside air. Check the valve covers, the oil pan gasket or other sealing areas for leaks. |
| • | If the vacuum gage registers a pressure, or if the vacuum gage is pushed out of dipstick tube, check for a plugged PCV port, a plugged hose or excessive engine blow-by. |
