My YJ has a 2.5 motor and I have been having some problems since I bought it about 6 months ago. The motor will knock pretty loud while it is at idle, even when it is at running temp. Some days It feels like I have a 6 cylinder motor but then there is some days when I can barley get over 50 mph. It has a aftermarket cai and I recharged the filter and it did nothing. When I first got the jeep the motor oil was very black and old looking. The motor only runs at 125 degrees, and I thought that that was almost to low. This is the second motor and the previous owner told me that this motor has around 75,000 miles, The jeep has 185,000 miles on the rest. Any info would be helpful.