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Cylinder Combustion Pressure Leakage

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Ensure that parking brake is applied and transmission is in Park or Neutral when performing this test.
  1. Start and warm engine to normal operating temperature. Turn engine off. On 3.0L engines, remove intake manifold and install Debris Screen (J-45482) over intake spacer. See INTAKE MANIFOLD in appropriate article in ENGINES. On all engines, remove ignition modules and remove spark plugs.
  2. Rotate crankshaft so each cylinder to be checked is at Top Dead Center (TDC). Check timing marks. A brass rod can inserted into spark plug hole to determine piston location relative to TDC.
  3. Attach air supply to Gauge Bar Set (SA9127E) to cylinder. Adjust gauge bar regulator pressure to 125-150 psi (861-1034 kPa). Insert cylinder leakage adapter into spark plug hole with piston at TDC. Ensure crankshaft does not rotate. If crankshaft rotates, piston was not in TDC.
  4. Close gate valve and adjust regulator pressure to 100 psi (689 kPa). Open gate valve. Observe crankshaft. Allow 60 seconds for air pressure in the cylinder to stabilize. Observe pressure gauge and record pressure.
  5. Listen for escaping air at throttle body inlet, oil fill cap and exhaust outlet. Remove coolant bottle pressure cap and look for bubbles. Repeat procedure on other cylinders and record readings. Normal leakage is 10 percent or 10 psi (69 kPa) and maximum leakage is 20 percent or 20 psi (138 kPa). Difference between cylinder should be about 5 percent 5 psi (34 kPa).
  6. Reinstall spark plugs and ignition module. On 3.0L engine, install intake manifold.
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