1953-1960 Classic Car Engines Troubleshooting Guide: Engine Oil Leakage

The text for this Guide originally appeared in the 23rd edition of Motor's Repair Manual, published in 1960 and copyrighted by Motor Information Systems, and is used with their permission.

Things to Look For:

1. Oil pan drain plug loose or gasket missing.
2. Crack or hole in oil pan.
3. Oil pan gasket leaks due to: (a) loose screws; (b) damaged gasket; (c) improperly installed gasket; (d) bent oil pan flange.
4. Timing case cover gasket leaks due to: (a) loose screws; (b) damaged gasket; (c) improperly installed gasket; (d) bent cover flange; (e) leakage at engine support plate.
5. Front crankshaft oil seal leaks due to: (a) worn oil seal; (b) seal not properly installed; (c) rough surface on crankshaft, or fan pulley or damper; (d) damper or pulley loose; (e) seal or cover not centered on crankshaft; (f) oil return passage to crankcase clogged up (if provided).
6. Rear main bearing oil seal leaks due to: (a) worn oil seal; (b) improper oil seal installation; (c) worn rear main bearing; (d) rough crankshaft surface.
7. Oil return passage to crankcase clogged.
8. Expansion plug in block at rear of camshaft leaks due to poor fit, careless installation, or corrosion.
9. Leakage at any external piping.
10. Plugs at ends of oil passages in cylinder block leak.
11. Oil filter leaks.
12. Leakage at distributor housing.
13. Valve cover leaks due to loose screws, defective gasket, improperly installed gasket or bent cover flange.
14. Rocker arm cover or push rod cover leaks because of loose screws, defective gasket, improper gasket installation or bent cover flange.
15. Pipe connections loose on oil gauge or oil filter lines.
16. Loose oil pump or faulty gasket (if pump is on outside of block).
17. Clogged breather and/or crankcase ventilating discharge pipe, permits increase in pressure within engine, thus causing oil to be forced out past any oil seals or gaskets.
18. If oil pressure relief valve is mounted on outside of block, leakage may occur if unit is loose or its gasket defective.

The Complete Guide to Troubleshooting 1953-1960 Era American Classic Car Engines