Chrysler Repair: Oil Light on at idle, chrysler neon 2002, fuel dealership

Question
Good day,  my Chrysler Neon 2002 1.6i oil light keeps on going on when I put my foot on the clutch or reduce speed.  I have replaced oil pump, cambelt and relay already, replaced fuel.  Dealership says they do not know what is wrong - a lot of money later on!!! I really like my car, and would not like to sell... I have tried everything at my disposal, including Chrysler Customer Care... PLEAAASE HELP!!!

Answer
Hi Mynie,
I am sorry to learn about all the expenses, I hope some were not related to just this problem. As an engine wears the resistance to oil flow in tight spaces reduces so it moves through them more easily and the overall pressure in the system drops. The oil pump too becomes less efficient but you already replaced that. I wonder if the shops have measured the actual oil pressure when the engine is idling and warmed up? I doubt it is below the minimum specification of 5 pounds per square inch, and it may not be worth paying to have that done anyway. You know the warning light is working... but I suspect it is set to go off when the pressure drops to less than a number greater than 5.
This is fairly common with all makes/models. Your idle rpm too could be a little on the low side which means the pressure is going to be low enough to turn on the light after the engine warms the oil, which also lowers the pressure a bit.
But in my experience I would not be concerned for the moment, but rather the next time you change the oil increase the 'weight' by one step*, which increases the viscosity and thus will raise the pressure at idle so that the light will usually not come on anymore. Another approach would be to buy a new sensor for the light and replace the present one which may be off-value. Either of those approaches don't have any labor charges if you do it yourself.
The only time you really have to be concerned is if the light comes 'on' when you are driving and the rpm is higher than about 1,200 rpm as that could mean there is insufficient oil reaching all the moving parts.
The oil costs the same no matter what 'weight' you buy so increase it one step and see if that eliminates the warning light problem. Also, if you have been buying synthetic oil you could switch to conventional oil which produces a higher pressure reading for the same operating conditions. It costs less as well.
Roland
*If you have been using 5W-20 try instead 10W-30, for example; or if 10W-30 try 20W-40.