Alright, I'm lost!! 1969 350 When first started has no oil pressure for about 3-4 seconds then it climbs to normal range. Then it begins to badly fluctuate from 35 to 15 to 20 to 40......very erratic up and down. Sound like a bad oil pump???? Ok, now to the good stuff. Do I HAVE to pull the engine to replace/rebuild this oil pump?? I thought this was an external pump by the oil filter. If this is the case do I have to replace the pick up as well?? Year one only sells the rebuild kit for the oil pump separate from the pick up and gear thrust plate. Any advice on doing this job or on another diagnosis for my problem is greatly appreciated. HELP!!!!!!!!!!
Sounds like the pickup could be clogged. I would check that first. You may not need to touch the pump at all. The oil pump on a Buick 350 or 455 is part of the timing chain cover, and it is indeed external. If you remove the oil filter and the small bolts securing the filter nipple assembly to the timing cover, you will see a pocket with 2 gears. One is driven off the bottom of the distributor, the other is driven by the 1st gear. The clearances between the gear teeth and pocket, and the gear faces and pump cover, are very important. This and your main/rod bearing clearances, are what determine how good your oil pressure will be. WHENEVER, you disturb the oil pump cover, you need to pack the pump with vaseline. This is necessary to make sure the pump primes when you fire the engine back up. Check your pickup first, and go from there.
oil pump i put a boost plate and pike up tube. the plate was ez. but i did it with a c&c machine. you have to drill two 1/8 holes. you can do it with a drill. it come with 3 different springs for different preachers. ~josh