Engine Oil Leaks
DESCRIPTIONWhen diagnosing engine oil leaks, the source and location of the leak must be identified before service. The following procedure is very effective and requires minimum equipment. Prior to using this procedure, clean the cylinder block, cylinder heads, valve covers, oil pan and flywheel with a suitable solvent to remove all traces of oil.
For an oil leak diagnosis using Rotunda Oil Leak Detector 164-R0756 or equivalent, perform the following procedure:
FLUORESCENT OIL ADDITIVE METHOD
1. Clean engine with a suitable solvent to remove all traces of oil.
2. Drain engine oil crankcase and refill with recommended oil, premixed with Fluorescent Oil Additive ESE-M99C103-A or equivalent. Use a minimum 14.8 ml (0.5 ounce) to a maximum 29.6 ml (1 ounce) of fluorescent additive to all engines. If oil is not premixed, fluorescent additive must first be added to crankcase.
3. Run engine for 15 minutes. Stop engine and inspect all seal and gasket areas for leaks using Rotunda Oil Leak Detector 164-R0756 or equivalent. A clear bright yellow or orange area will identify leak. For extremely small leaks, several hours may be required for the leak to appear.
4. If necessary, pressurize main oil gallery system to locate leaks due to improperly sealed, loose or cocked plugs. If flywheel bolts leak oil, look for sealer on threads.
5. Service all leaks as required.
PRESSURE METHOD
The crankcase can be pressurized to locate oil leaks.
The following materials are required to fabricate the tool to be used:
- Air supply and air hose
- Air pressure gauge that registers pressure in 4 kPa (1 psi) increments
- Air line shutoff valve
- Appropriate fittings to attach the above parts to oil fill, and PCV grommet holes and crankcase ventilation tube
- Appropriate plugs to seal any openings leading to the crankcase
- A solution of liquid detergent and water to be applied with a suitable applicator such as a squirt bottle or brush
Fabricate the air supply hose to include the air line shutoff valve and the appropriate adapter to permit the air to enter the engine through the positive crankcase ventilation valve opening. Fabricate the air pressure gauge to a suitable adapter for installation on the engine at the oil fill opening.
Testing Procedure
1. Open air supply valve until pressure gauge maintains 34.5 kPa (5 psi).
2. Inspect the sealed/gasketed areas for leaks by applying "Snoop Pressure Check" or a solution of liquid detergent and water over the areas for the formation of bubbles, which indicates leakage.
LEAKAGE POINTS
Examine the following areas for oil leakage:
Underhood
- Valve cover gaskets
- Intake manifold gaskets
- Cylinder head gasket
- Engine front cover gasket
- Distributor O-ring
- Oil level indicator tube connection
- Oil pressure sensor
- Oil bypass filter
Under Engine with Vehicle on Hoist
- 0il pan gasket
- Oil pan front/oil pan rear seal
- Crankshaft front seal
- Crankshaft rear oil seal
With Transaxle and Flywheel Removed
- Crankshaft rear oil seal rear main bearing cap parting line
- Camshaft rear bearing covers/pipe plugs at the end of oil passages
NOTE: Light foaming equally around rocker arm/camshaft cover bolts and crankshaft seals is not detrimental and no corrections are required.
Air leakage in the area around a crankshaft rear oil seal does not necessarily indicate a crankshaft rear oil seal leak. However, if no other cause can be found for oil leakage, assume that the crankshaft rear oil seal is the cause of the oil leak.
Oil leaks at crimped seams in sheet metal parts and cracks in cast or stamped parts can be detected when pressurizing the crankcase.