For 1990-2009 cars

#### Special Tools

EN 23951 Manometer

For equivalent regional tools, refer to Special Tools.

Note: Oil in the charged air cooler, hoses, turbocharger, or intake manifolds is normal with a closed crankcase ventilation system.

1. Remove the oil level indicator. Install a EN 23951 manometer or equivalent.
2. Start the engine.
3. Check for slight vacuum. The vacuum level should be less than XXX kPa (X in Hg).
4. If vacuum is higher, inspect and verify that the clean air hose from cam cover to air intake is not blocked or kinked.
5. If vacuum is in the normal range, block or pinch off the clean air hose. The clean air hose is the hose between the cam cover and air intake system. Vacuum should increase on the manometer. If held too long, vacuum will be drawn through the crankshaft seals creating a sucking sound.
6. If vacuum does not increase, the orifice in the intake manifold could be plugged.
7. If there is zero vacuum or pressure, verify compression of the engine.
8. If compression is normal, check for a blocked orifice at the intake manifold. Clean the orifice.