If an oil leak can’t be located, clean the engine with an aerosol degreaser; then spray aerosol foot powder on its sides and bottom. The leak will form a line in the white powder.
You maybe able to to fix a leaking oil filter by simply tightening the filter. If the leak is at the oil pan, valve cover, or mechanical fuel pump, tightening the bolts or nuts may solve the problem. On a cover with many screws, start tightening in the center and work alternately toward the ends. If the leak persists, you maybe able to change the gasket, but leave an oil-pan gasket to a pro.
Remove the screws; if the valve cover is stuck, pry it up. Tape identifying numbers to any hoses or wires you unplug.
Using aputty knife, scrape gasket residue from the cover and the cylinder head. If the head is aluminum, take care not to gouge it. If a metal cover rocks on a flat table, it’s warped. Sandwich it between flat pieces of wood, then hammer gently on the edges of the upper piece.
Apply a film of pliable gasket sealer to the cover’s gasket surface, then fit a new gasket. A precut cork-fiber or cork-rubber gasket is best for a sealing problem.
Position the cover and the gasket, then thread in the screws and washers. Working from the center out, fin
gertighten, then tighten moderately with a wrench, and then securely.
Fuel pumpgasket. Disconnect the fuel lines. If a pump has a threaded fitting, hold it with one wrench; use another to loosen the fuel-line nut.
Catch fuel with a rag. Remove retaining nuts or bolts; pull off the pump.
Scrape the pump and engine surfaces. If the gasket is a thin sheet, use two sheets. Apply pliable sealer to the pump surface, then a gasket, another coat of sealer, and the second gasket. Refit the pump and gradually tighten the nuts or bolts. If the engine has a pushrod, suspend it with a paper clip while guiding the fuel pump into place.