11 - Crankcase Pressure Test

11. Crankcase Pressure Test






Purpose:
This test will measure crankcase pressure. Crankcase pressure is a measure of how well the cylinders are sealing.

Recommended Procedure:

NOTE: Do not plug hole on Crankcase Orifice Restrictor Tool 014-00743.






Make sure the engine is up to operating temperature. A cold engine will give higher readings. Remove the ducting to the turbocharger inlet pipe and remove the inlet pipe and elbow that connects to the breather box. Block the outlet at the breather box with the cap provided in Pressure Test Adapter Kit 014-00761 or equivalent. Install a protective screen over the turbocharger inlet.

Screw the Crankcase Orifice Restrictor Tool 014-00743 and Crankcase Pressure Test Adapter or equivalent in the oil fill cap hole. Plumb to the Magnehelic (R) gauge in the gauge block. Make sure the Magnehelic� gauge has been zeroed.

Start the engine and operate at 3400 rpm. Hold for 30 seconds minimum and take a stabilized reading. Do not block the hole at the top of the restrictor tool.

Possible Causes:
- Broken or worn compression rings
- Polished cylinder bores
- Leaking or bent valves

Inspect air induction system. If the air induction system allows dirt to enter the cylinders, it will quickly "dust" the engine causing high crankcase pressure.

Tools Required:
- Crankcase Orifice Restrictor Tool 014-00743 (part of Pressure Test Adapter kit 014-00761)
- Magnehelic (Del) gauge (part of Pressure Test Kit 014-00761)
- Protective screen
- Crankcase Pressure Test Adapter 014-00743 or equivalent