Ok, I have a very weird oil problem with my car right now.
I'll be in traffic, stopped at a light. My oil guage will then jump back and forth between 40 and 60, and the idle will get slightly rougher then normal. About 4-5 seconds later, the car will idle smoothly, almost like it died or something, but the "service engine soon" light will come on. After driving down the road for about a minute, the check engine light will turn off.
What's wrong with the car??? Could I have a bad oil pump or something?
I don't think the oil is causing the rough idle, i think the rough idle is causing the oil problem. 40 psi at idle is pretty good, 60 is kidna high. So if the rpms are jumping a little, so probably will the guage. It would be helpful to find out why the SES light is coming on, ie what code is setting.
I had the same problem with mine. It turned out to be that the oxygen sensor was bad. The computer was setting the "oxygen sensor lean code". When the check engine light come on, it is the computer going to a fail safe mode, that's why it smooths out. Then once you are driving again the o2 signal is back within acceptable range for readings even though it is still way off. I replaced the O2 sensor and it has been just fine ever since.
You rock, I just replaced my O2 sensor, and it feels like a new car! No more rough idle and jumping oil needle.