I have a slight oil leak on my 1993 Honda ACCORD ex. It has about 156k miles. I change the oil between ever 3k-4k miles. I had a bad leak last year and replaced the water pump, timing belt, and valve cover and gaskets. It was fine for a year and no its starting to leak again, bit not as bad. Mechanic tightened the valve cover but still seems to be leaking. Any idea where the problem may be ? Doesn it need to be addressed? or can i just monitor the oil level. Currently has 10w 40 after recent change. Thanks in advance for any help.