If the oil pump needs resealing, does the car fail to get oil pressure right away on every cold start or is it intermitant? I am asking because, when my car was running poorly, it would take awhile to build up pressure...not long, just longer than normal. But since I have replaced the crankshaft sensor, it seems to get oil pressure just fine on cold starts. Hate to tear it apart if I don't need to.

You're really not gaining oil pressure by resealing the oil pump. What happens is the backing plate on the oil pump has screws that sometimes back out. This increases the clearance between the rotors, so oil pressure/flow isn't as great as it should be.

 

Also, if the o-ring between the block and oil pump is worn, you may loose pressure through that.

finally contacted previous owner. Discovered that oil pump was not resealed with timing belt at 160K so will do the work anyway just in case