440 oil light

Anyone know why my oil light comes on at low revs. There is plenty of oil in
the engine.

 

Often older cars with some internal engine wear suffer this problem when the
engine is warm at very low RPM's.

The oil pump has worn a tad, and just does not pump like it use to. The
main bearings have worn a tad too and are more likely to let oil seep by
faster they the design spec, so the oil does not build up as much pressure
when the engine is not turning the oil pump fast enough.

It's conceivable that the fault is in the sending unit as well....

Solution 1: Fughetaboutit!
Solution 2: Replace the oil pump, and hey while the pans off do the mains
too...
Solution 3: Get an oil pressure gauge and thread it into the hole where the
oil pressure sending unit lives and see what kinds of pressures you have at
different rpms and operating temps.
Solution 4: Solution 1 with the addition of checking the oil level every few
days **just to be sure** with an ear out for unusual mechanical noises.

 

In addition to the effects of wear, it is possible there is a serious
failure taking place, or that the sensor is getting weak and annoying you
with false alarms. I strongly recommend you get the oil pressure checked -
it isn't expensive - and if it is acceptable (a mechanic with a radio show
said 6 psi is the minimum pressure for idle, but I really don't know) a new
sender may do the trick.

Mike

 

Bearings on way out, oil is wrong grade, idle too low, oil pressure relief
valve needs cleaning/adjustment/replacement, filter getting blocked.

Cheers, Peter.