Ok so I have a 2002 f150 with the 5.4 .. Not sure which trans yet ... Ok so I've had what we thought was a small vacuum leak and I was driving the other day at a steady 55mph and all of a sudden my rmps jump from 1000 to about 1500 (coming in an out of overdrive )and it dose this a few times later that night it happened at a steady 40mph too , next had my truck was lower to shift but still running fine other wise .. Hasn't done any of that in the last few days but has kept the slightly high idle at times .. Needing advice ?

 

Is it cycling between 4th and overdrive? Or is slipping in and out of overdrive? If you turn overdrive off does it still persist?

 

Any OBD2 codes?

Joey - 4th is overdrive - direct is 3rd.

 

No codes other than a speed sencer on my left front wheel and its jumping between 3rd an OD.. My light for my OD **** hasn't worked in two years .. Just thought it burnt out .. But I found out today that it's prolly a fuse gone bad so I'm not sure with that

 

When the OD light doesn't work it is usually a broken wire where it enters the shift handle inside the column. Take the plastic cover off the column and you will see the wires. Either fix the break or buy a new shift handle for about $65 from a Ford dealer.

If the wire to the OD button is also broken it could be shorting to the column. This could cause it to cycle between 3rd and OD.

 

I don't think the light /button has anything to do with the direct issue it's been broken for 2yrs and the problem came about at the end of just this winter started as just a high idle ... But atleast I know how to fix the button now thanks

 

You're the transmission expert, I was just telling you that I've seen this happen before. But I'm now sure yours is different.