Question for the engine guru's

[rogercv1 at gmail.com (Roger concha)]

88 16V with about 160K on the motor.
lately after highway driving or city driving once the temp on the car
comes to normal the oil light will come on once I drop below 3K rpms
and will turn off once back over 3K not just driving rpm's I can just
tap the throttle to get it over 3K and it will stop.

there is enough oil in the car.

so I am stumped.

any Ideas.

thanks
Rog