Have a 92 Accord EX 5spd with 165000 miles on it. I have been using 5-20 Valvoline oil for the past 3 or 4 oil changes. In the past 5000 miles after the car sits for a few hours I have a clicking or knocking sound coming from the motor when I accel under load and I have noticed a slight oil leak from between the tranny and motor(seems like one drip every few days). Once I drive the car for about a mile or so the sound seems to go away.. Does anyone have any sugestions on what this might be? I know Honda recommends 5-30 but could the 5-20 be causing this?