I have a 1984 ford f-250 with a 460. Just recently i was driving it and the oil pressure dropped to barely touching the N on the guage, and it started to rattle. It doesn't rattle hard like a ring went out, and it doesn't blow oil unless you really get on it. Also, if u are giving it gas, it won't rattle. I think the rod bearings might be going out on one piston. Also, my dip stick keeps popping up, why? What do u guys think? Any advice is welcome. Thank you.

 

sounds like you need a new pcv valve- thats probably why your dipstick pops up. as for the rattle id have to hear it to tell you what it could be. did you check the oil? sounds like it might be a quart or two low. how many miles on it?

 

All the symptoms you describe sound like the engine has a lot of wear.

Low oil pressure, bearings worn out.

Dipstick popping out, lots of pressure inside the engine which means the piston rings are worn. The PCV valve would be a good thing to check, but if it rattles and has vacuum, then it's probably working.

How much oil does it use?

 

it uses about 2 quarts of oil per 150 miles on the interstate. I just put a new pvc valve in it, and there's plenty of vaccum. it does suck air through the top inlet of the pcv valve, and i plugged it off. i'm not sure on how many miles, but i'm guesing close to 180,000. Was a farm truck before i got it, so it's been through some tough work. it has enough oil, that i checked. it starts once it warms up, and it's not all cylinders, just one. Bearings?