ever since ive had this 99 explorer (1YR)4.0 sohv 150'000MILES at cold start ups there is a bearing noise it lasts about 2seconds and oil pressure is normal i use Valvoline 5w30 ive put lucas oil stabilizer seems to help a little and oil stays clean for 2000 miles but im wondering is this normal or an issue thats gonna poke its ugly head up? if not normal any ideas on how to repair? is it worth it? ive had several fords in the past and never that kind of noise please help or tell me to turn up the radio!