I have a 2001 Supercrew 4x4 with the 5.4 engine . When the temp drops below 35 degrees , My oil pressure guage reads no oil pressure . If I rev the engine a little , it will go to where it's supposed to be , then drop back to 0 .It will only do this for about 1 minute , then will be fine . Do I have a bad oil pressure switch , or something worse ?

 

Won't know for sure without putting a mechanical gauge on it and verifying that you really do or don't have oil pressure. But I'd suspect the sender too, replaced a bunch of 'em before for the same problem.

 

i'd replace the sender unit frist my mom 99 exploder did the same thing