papa tiger

Don't know what motor/f150 year you have but it is directly proportional to the spinning of the motor crankshaft. I would guess a loose bolt rubbing from the flex plate. You could inspect for that befor tear down. Also loosen the belts and stop the turning up front. Sound has a way of moving around and removing sources help pinpoint it. I do believe it is in the engine to trans area. Torque convertors can get perty sticky wicky and parts inside them wear out and break. Usually with a loss of torque power. Vibrate/shake/squeel and tear up stuff in the trans also. Good luck It's a lot of money spent if you can't locate and fix yourself.

s_vares

Good call! and maybe inspect starter

ussoldier1984

there is a service recall on that at ford. any 1-2-3-4 shift where it lingers between gears and just revs. If it applies to your year its a simple reprogram of the ecu, I know this because I had the same 3-4 issue. Free of charge they reprogrammed my ecu and never had a shift issue again.

Edit: I think it was 3-4 but might have been 1-2 anyway there is a reprogram for either one.

Rick's 06

Like others have said it's not the fuel pump. The sound is synced exactly with your engine rpm, so it sounds like a bad bearing or something. What's making this interesting is the fact that the engine area is quiet. That's where the sound should be coming from. Let us know what the shop says.

Rubicon35

yea when i pop the hood it is just as quiet as the day i bought it. i turned the steering to bog the motor a little so you can hear the change in pitch. its got a powertrain warranty until 60k miles and i have 58k so its covered. it is a 2008 4.6l, auto is the same as the 5.4 so the 4r75e, they started this in 2008 on the 4.6ls

Rubicon35

and if it wasnt under warranty and its the trans it would be getting a built unit to replace it. plan on forced induction in the near future anyways. ill make sure ford fixes it. my local dealer has always been reasonable and i have an appt with the tranny guy monday morning to take a quick peak.

Rubicon35

Transmission is on a bench at ford. Going to crack it open tomorrow. Will update everyone on what the problem is when I hear from them.

Rubicon35

Tranny got a full rebuild. Outer Bearing number 9 and one other where severly worn. Alot of small metal particles in the pan. 2/3 shift solenoid sticking. Drives great. But there is a new noise during warm up. It's sounds like a baby's rattle and it matches engine rpm. Not really loud and it fades as the truck warms up. Gonna drive it a few more days before I bring it back in.

papa tiger

I always believe in changing the torque convertor with trans job/ high mileage. Seen too many comebacks from others going the cheaper fix, but that's a warranty issue too probably. Clutch is a different story.