Engine Oil Leaks

FLUORESCENT OIL ADDITIVE METHOD
When 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 12 Volt Master UV Diagnostic Kit 164-R0756 or equivalent, perform the following procedure:

1. CAUTION: Aluminum engines must be at room temperature when being cleaned or engine damage (component warping) may occur.

Clean engine with a suitable solvent to remove all traces of oil.
2. Drain engine oil crankcase and refill with Motorcraft Super Premium SAE 5W-30 Motor Oil XO-5W30-QSP or equivalent meeting Ford specification WSS-102C153-G premixed with Fluorescent Oil Additive or equivalent meeting Ford specification ESE-M99C103-B1. Use a minimum 14.8 ml (1/2 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 12 volt Master UV Diagnostic Kit 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

Materials Needed
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 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 and/or gasketed areas for leaks by applying snoop leak detector or a solution of liquid detergent and water over the areas for the formation of bubbles, which indicates leakage.

LEAKAGE POINTS

Underhood
Examine the following areas for oil leakage:
- valve cover gaskets
- intake manifold gaskets
- cylinder head gaskets
- engine front cover gasket
- camshaft position sensor O-ring
- oil level indicator tube connection
- oil pressure sensor
- oil bypass filter

Under Engine-With Vehicle on Hoist
Examine the following areas for oil leakage:
- oil pan gasket
- oil pan front and/or oil pan rear seal [3.0L (4V)]
- crankshaft front seal
- crankshaft rear oil seal

Under Engine - With Transaxle and Flywheel Removed
Examine the following areas for oil leakage:

NOTE: 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.

- crankshaft rear oil seal
- crankshaft rear oil seal retainer
- rear main bearing cap and seals [3.0L (2V) engine]
- camshaft rear bearing covers, and/or pipe plugs at the end of oil passages

NOTE: Light foaming equally around valve cover bolts and crankshaft seals is not detrimental and no corrections are required.
Oil leaks at crimped seams in sheet metal parts and cracks in cast or stamped parts, can be detected when pressurizing the crankcase.