I just bought a 99 Intrepid, 2.7 with 131,000 miles on it. RUNS like a swiss watch, purrs like a kitten. I had heard of the sludge problem with these and was told not to buy it, but the price was right, so after I fixed the problems it had (window, ball joints and tires), I topped off the oil with a 1/2 quart of ATF (old trick I have always used as an old mechanic friend told about this 25 years ago). Then about 500 miles later, I changed the oil and filter, went cheap this time as that was all that money allowed, figuring I could go back to synthentic at the next oil change. Now, three weeks later, the oil light flickers and stays on once the car idles down to 500 rpm's after it is warmed up to operating temperature. After reading the forum, I am confused. Today I am going to change the oil again and put in Mobile one and a new Fram filter. And see if this changes things. Please someone post, as to what I should do, or stop me if I am making things worse. I bought car from impound and have no knowledge of previous maintenance. I am fairly new to the 1990's in vehicles, as my previous newest cars have been 93 Imperial, 91 Escort (Should have kept this one), 90 G30 and 98 Contour (now I know why I got this one cheap). Any help would be greatly appreciated.