Have a 99 grand cherokee laredo 6 cyl when im driving oil pressure is just above 40 on gauge when i stop or it drops to around 10-20 then when i move again goes back to just above 40.A friend said it could be a bad oill pressure switch or sending unit are these the same thing?and where is it located on 99 grand cherokee 6cyl?Or could a bad oil pump cause this.

 

The oil pressure will drop at idle and go back up while driving. The sending unit is located right next to the oil filter, you almost break it every time you change the filter.

 

is it on the same side as cam position sensor?

 

Yup. 10 psi at idle ain't too bad as long as it comes up when driving.