99 Grand Caravan Oil light/Chime

[Rob]

Hello all


I have a 99 grand caravan with 140k on it V6. This problem just started, Oil light flickers and chime sounds indicating low oil. Oil level is fine, no noise from oil pump also. Some days it is on other days it is not. Changed oil pressure switch, still have problem. Sometimes when stopping oil light comes on and on take off light goes out SOMETIMES arghhhh Anyone have any ideas. Thanks Rob

[DanD]

The first thing to do is to have the actual engine oil pressure tested by the use of a mechanical oil pressure gauge.
They give you a wide range in the spec (according to Mitchell)
: 3 Lt. engine 10 psi @ idle, 45 to 75 psi @ 3000 rpm.
: 3.3 & 3.8 Lt. engine 5psi @ idle, 30 to 80 psi @ 3000rpm.
If not within spec at idle, as in to low you’ll have to start looking for internal engine problems such as weak oil pump, pressure relief valve or general overall engine wear.
As for which is the cause is kind of like answering the age-old question was it the chicken or the egg that came first. All is depending on mileage and what may have happened to the engine in the past.
If the oil pressure is within spec you’ll have to start doing pin checks making sure that the signal from the oil pressure switch is getting to the body computer. That the body computer is recognizing the signal properly, then whether it’s sending the proper signal to the driver’s information center. Last but not least is whether the information center is properly recognizing that signal. All of this has to be done through a scan tool, a multi meter by someone that is familiar with the system.
If by chance the pressure switch was replaced with anything other then the manufacturer’s switch I would back track and get an OE in there before anything else is done.
Dan.