my 2001 f150 seems to have a problem with the oil pressure, when you first start it up the oil pressure gauge reads normal and no light, at idle everything id fine, you drive it about a mile and the oil pressure gauge is fine i slow down to turn the truck around and the oil pressure gauge drops to nothing and the light comes on, the truck runs a but rough but i though it was because it set for 2 years, now i am wondering if it was put back together right since i sent the truck to a vo tech school to have the timing chain replaced and it took them forever to get it done, they had to pull a head and fix a valve because they did not get the timing chain put on right the first time and when i got it back the valve cover was loose, the truck runs rough and has a very slight tick/knock.

I changed out the oil pressure sensor to make sure that it is not a sensor problem and my next move it to put a manual gauge on it to see what happens then,

could their be something loose on that bank on the engine that would allow the engine to have oil pressure at idle and while going down the road but cause it to loose pressure and not go back up after it warms up and has went back to idle, it is a single OH cam 4.6L V8.

 

How many miles? When you rev it up sitting still do you lose pressure?
They could have screwed up something. I assume it started exactly when you go it back. I would go see the shop teacher and find out everything I could about what they did to your truck.

 

it has 230k on it and as far as i know they did the timing chain and when they tried to start it the first time it bent a valve so they pulled the head in the passenger side of the truck and had the head repaired, i have sent an email to the teacher but it is summer and i am not sure if he will get it till Aug.

I was only driviving it about 45 - 50 so about 3000 rpm or so, i have noticed it seems to miss a bit more after you rev it up and the oil pressure gauge in the dash drops,

i am planning to pull the valve cover and check the bolts on that side that hold the cam down. when i got it back it needed a starter ( that was a whole other issue ) and i found that the valve cover and exhaust was still loose on that side it was like they just put the things in finger tight and left it, i am guessing that they didn't tighten down the cam retaining bolts and that is what is causing the drop in oil pressure.