Chrysler Repair: 2005 Chrysler 300 oil pressure light, 2005 chrysler 300, low oil pressure

Question
I have a 2005 Chrysler 300, 2.7L with about 127,000 miles on it. The low oil pressure light comes on when ideling after it has warmed up. It idles at about 700 rpms. I use to take it to a chrysler dealership to get it serviced but they closed down and it has been to two diffrent places sence, it didn't start until about a month ago and was not an every day thing but has turned into one. The last place used a synthetic 5w30 oil. I dont know what the dealership used. I have read all the horror stories about the car with this engine and my mechanic, who is suppose to be changing the oil sensor on Sunday, says it doesnt look/sound good. Do you have any suggestions? Is my car shot?

Answer
Hi Emily,
I would not be too concerned about this light coming on at idle. This is a fairly common experience with all engines. The oil pressure sensor may be a bit pessimistic and warning you falsely. That could be checked out by having the mechanic check whether the oil pressure is at least 5 psi at idle which he would do by testing it at the pressure sensor located next to the oil filter.
More likely the reason is that the synthetic 5W-30 oil has too low a viscosity number for the engine at this point in its life which thus causes the pressure to be lower than it could be at idle. I would recommend that you increase the 'weight' of the oil to 10w-30 which will no doubt raise the pressure and turn 'off' the light at idle, with no further risk to the engine.
So don't panic...just change to the higher number of oil. Regular oil also has a thicker viscosity than synthetic, so you might forgo that extra cost and use regular oil as well
Roland
PS: Sorry for the delay in answering but I just became aware of it when I checked the 'pool' to which it had been referred. May I ask a favor? I am competing to be recognized as 'volunteer of the month' at Allexperts. If you would click on the "Thank/rate the expert" button below it will take you to the page where you will see the question "Would you like to nominate the expert to be volunteer of the month?"  If you would click on "yes" I would be most appreciative.
Merry Christmas!