Oil is thicker when it is cold. When your engine is warm (after driving a long time) the oil is thinner and your
oil pump has a harder time to keep pressure up.
You might also have worn bearings in the engine that is causing loss of pressure due to excessive clearance
between bearings & shafts (crankshaft, connecting rod journals), that thicker oil can handle, but warm thin oil
You will need to have the engine inspected for wear, and possibly start with a new oil pump.
Saturday, October 20th, 2012 AT 12:09 AM