Oil Problem

[Inquisitorshea]

I have a 96 ford explorer with 140k miles. Just recently when it got colder her in dallas (around 35°) my oil pressure gauge suddenly dropped to zero. When I revved up the engine the gauge would shoot up to normal for a split second then fall back. Then the next day after leaving work the engine started making a loud clanking sound. I checked the oil level and it read fine on the dipstick. I was told that it may be a bad oil pump. Does that sound about right? Also if I wanted to change the oil pump my self would I have to remove/Jack up the engine to do so or can I just get to the pan easily? I'm not exactly the best mechanic but I will have some help, better than the $550 dollars I would have to pay to get a shop to do it.

 

[BIGHVM]

Do you have any smoking from the exhaust? if its blue or dense, you may have worn piston rings- that would loose oil pressure. I would do a compression test to confirm this.
Firstly I would check the oil pick up- it may be blocked with mess loosened from the oil change- clean the pan whilst you are there- bet its caked in thick goo! Then check the oil pump mate, it is the likely cause------Please do not drive the car till this is fixed you will wreck the engine..........sounds like the big end bearings are not getting oil!

however, dont drive the car till you have dropped the pan, you can access it well from below, no need to jack up the car, have a look at the oil pick up and see if its clear