Chrysler Repair: 2000 2.7L 132k miles - oil light flickers at low RPM and general maintenance, light flickers, oil pressure sender

Question
Hi Roland - I appreciate the help.  I have a 2000 Chrysler Condcorde.  We bought it used about 4 years ago.  It had 19k miles on it.  I drive a long way to work and so now, four years later it has 132,500 miles on it.   Recently, on occasion, when stopped (at a light) the engine RPM drops below 500 rpm and the oil light flickers.   I change the oil every 4000-6000 miles but don't want to be stuck if the engine is building up sludge etc.   Anything I can do to check this out or fix it?   

Thanks so much, John

P.S. We've been trying to decide on trading this in, or keeping it a while longer (but want to be sure it'll keep running and be safe).  I've had no major (or minor) repairs that I can recall with this car so far and almost all the mileage I've put on it is highway miles.  Any preventative maintenance you definately recommend to keep it going another 100k miles?  Thanks!

Answer
Hi John,
The oil pressure sender could be reading too low so either remove it and measure the pressure at idle with a calibrated gauge or simply replace it. It is located next to the oil filter. The minimum pressure requirement is 5 psi at idle. Another approach is to raise the "weight" of the oil one step which would result in higher pressures at all rpm. That would probably be my approach.
If the pressure light only comes on when the rpm dips, then that would be expected and the solution would be to get the idle rpm stable. I would get a fault code readout at Autozone parts store, often for free, and then let me know what fault codes came out of the engine controller memory.
You know there were problems with the 2.7 early in its career. And changing the oil regularly is probably a good preventive measure. Other than that you might Google the subject and get a history of the remediation others have taken. I haven't followed it closely.
Good luck on the measures. I think one of these will keep the light off and maintenance will keep you going much further. I would hold on to it as your driving patterns would cause the least amount issues for you.
Roland