I have a 2007 pacifica 4.0 .. the oil light comes on start up ever oncein a while.. motor runs good .. it stay on a few start and stops then the light go out..

 

Suggestion: Bad oil pressure sensor. Easy fix. . .
My oil light was intermittent as well so I decided to change my oil pressure sensor (approx $15 CDN) during an oil change to avoid a mess . .
* * NOTE: Special Tool - save yourself a whole lot of grief and get an "Oil Pressure Sensor Socket" from your local parts store. PartsSource or Canadian Tire will give you a socket set on loan if you have a credit card, just return it for full refund...you'll need this socket for peace of mind, otherwise you could chance it with one of your own sockets.
- Jack up vehicle and drain the oil
- remove passenger side front tire and inside wheel well cover
- you'll see the oil pressure sensor right in front of you; very close to belt pullies (some say you have to remove a tension pully, but I could not see why).
- Disconnect the wire clip (it's a combination clip...little red slider must be loosened before pulling the whole wire connection free....careful not to pull the little red clip out completely)
- Use your socket to remove the sensor
- replace with new sensor, reconnect wire, reinstall wheel well cover & wheel
**Don't forget to finish your oil change

This took my roughly 40-minutes start to finish.

Hope this helps somebody out there. Cheers

 

if you choose the wrong one,it will not run,the ringtone is to work with the CKP to tell the pcm where # 1 cylinder is