I'm getting some weird readings from my oil pressure guage in my 84 chev fullsize. THe engine is the 4.1L 250CU I6. When idling it reads just under 200 then in gear it reads 0. Also, when you drive it if you drive it real nice then it's fine but if you give er, it starts to tick faintly and gets louder and louder and louder. I'm thinking this has something to do with the amount of oil making it to the top of the head... Could this be a weak oil pump? Clogged?? Do I need to run thicker oil?? If it's a weak pump, how do I go about replacing it, any idea on parts cost? If it needs cleaning, how do i go about doing that, and what do i clean. The motor has 180,000k on it... Thnx.