low oil pressure

[Cal Metal]

Also, changing to 10W-40 might not be the best idea. The more additives it takes to widen the viscosity range, the less oil there is for real lubrication. Narrow that up a bit. Too many polymers run counter to good lubrication. Very few manufacturers recommend 10W-40 and will, in some cases, void the car's warranty if used. Mobil I (synthetic) is the exception, as they use no viscosity improvers in their 5W-30 or 10W-30 oil.

All synthetics are not created equal, however. Some do use polymer enhancers on the wide viscosity oils. Mobil 1 is the exception, however.