I have a 2002 S40 with 89K miles. Last week after an hour of stop and go driving the oil light started flickering and going on and off irregularly. I checked oil level and it was correct, and took the car immediately to my mechanic. He checked out the sensors, wiring, and oil pump and all tested no problem, and he noted that there were no error codes registered. He suggested I keep an eye on it, and I drove it for four days, about 200 miles, with no problem. This morning I was driving it to my transit station and after a block the oil light started to flicker again. Has anyone had a similar problem to this? Thanks!

 

What grade of oil are you using and is it synthetic or mineral type?

 

I have been using 5w30 synthetic and live in a very temperate climate.

 

At 89k it should be good on 5w30 synthetic.
Does she use much oil between changes?
Have you had the PCV system checked for any signs of positive crankcase pressure. May be starting to clog up.
Any yellowish creamy, mayo' like residue showing on the dipstick?