Engine Oil Leaks

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If an overnight drive is done, the fan air or road air blast can cause erroneous readings.

NOTE: When diagnosing engine oil leaks, the source and location of the leak must be positively identified prior to repair.

Prior to carrying out this procedure, clean the cylinder block, cylinder heads, valve covers, oil pan and flywheel with a suitable solvent to remove all traces of oil.

Engine Oil Leaks - Fluorescent Oil Additive Method

Use the 12 Volt Master UV Diagnostic Inspection Kit to perform the following procedure for oil leak diagnosis.

Add 29.6 ml (1 oz) of gasoline engine oil dye to a minimum of 0.47L (1/2 qt) and a maximum of 0.95L (1 qt) engine oil and fill through the engine oil fill. Thoroughly premix the gasoline engine oil dye or it will not have enough time to reach the crankcase, oil galleries and seal surfaces during this particular 15 minute test. The additive must be mixed well with oil and added through the oil fill. Check the level on the oil level indicator to determine what amount of oil to premix. If it is in the middle of the crosshatch area or below the full mark, use 0.95L (1 qt). If it is at the full mark, use 0.47L (1/2 qt).
Run the engine for 15 minutes. Stop the engine and inspect all seal and gasket areas for leaks using the UV Leak Detector Kit. A clear bright yellow or orange area will identify the leak. For extremely small leaks, several hours may be required for the leak to appear.
At the end of test, make sure the oil level is within the upper and lower oil indicator marks. Remove oil as necessary if it registers above the full mark.

Leakage Points - Underhood

Examine the following areas for oil leakage:

Valve cover gaskets
Intake manifold gaskets
Cylinder head gaskets
Oil bypass filter
Oil filter adapter
Engine front cover
Oil filter adapter and filter body
Oil level indicator tube connection
Engine Oil Pressure (EOP) switch

Leakage Points - Under Engine, With Vehicle on Hoist

Examine the following areas for oil leakage:

Oil pan gaskets
Oil pan sealer
Oil pan rear seal
Engine front cover gasket
Crankshaft front seal
Crankshaft rear oil seal
Crankshaft main bearing cap side bolts
Oil filter adapter and filter body
Oil cooler, if equipped

Leakage Points - With Transmission and Flywheel Removed

Examine the following areas for oil leakage:

Crankshaft rear oil seal
Rear main bearing cap parting line
Rear main bearing cap seals
Flexplate mounting bolt holes (with flexplate installed)
Camshaft rear bearing covers or pipe plugs at the end of oil passages

Oil leaks at crimped seams in sheet metal parts and cracks in cast or stamped parts can be detected when using the dye method.