Oil Pressure or Indicator problem?

I have a 99 Cheep Cherokee. The oil light comes on when the vehicle is in idle. However, it goes back to it's normal location when I either rev the engine or take off. The light is only on when the vehicle is in idle. Is this a oil pump problem or a indicator problem? Also, there is plenty of oil in the car so the engine is not using any addtional oil.

Thanks

Concerned Owner

The oil light only indicates a loss in pressure, it has nothing to do with oil level. The sender is not the most acurate or dependable thing. The best thing to do is connect a manual oil pressure gauge and see what the oil pressure really is. Auto parts stores carry them and some "loan" them. Post your findings and we'll take it from there.

do a manual test after the engine is at normal operating temp

Depending on where you live and the weather conditions there, and also what you do with it IE off roading, you might want to just try a heavier oil next oil change. My 92 was constantly having low pressure like around 5-10 according to gauge when idling but I switched to 5w-30 on one change and it's been where it should be ever since, also doesn't seem to make as much racket.

I would take out the sensor/sender and clean it and put it back in.

Or I would buy a new one. $56 bucks though.

http://www.automotiveforums.com/vbulletin/showthread.php?t=718061&highlight=oil+sender
An old post.