I recently bought a used 2012 F150 and all was well. But recently it picked up a squealing noise when accelerating and when the transmission shifts it stops and starts over. Related to RPM's it seems, any ideas on what it could be or where to start?

 

Which motor might help.

Seems like it would have to be a belt or the transmission.

Do you get any squealing on start up? If you manually shift the gears and hold it at a higher rpm and steady throttle does it keep making noise? If you have it in park/neutral and give it a hard rev do you get any noise? if it’ll do it while sitting still have someone spray a little water (very little) right before you rev it and see if that makes a difference

at either rate if they don’t look new an OE belt and new tensioner are fairly cheap and good practice anyway.

 

I have a 2010 F150 Platinum, and I was having the same issue. It was originally stated that it was the timing chain or something pertaining to the timing assembly. I had a mechanic take a look at it and he stated that one of the guides (where the bolt secures the guide to the engine) the attachment area was broken, and the guide was hanging there. I decided to have him replace the timing assembly entirely (guides, chain and the rest of the parts that come with the assembly). For about a month, everything was fine and then the same noise came back. I called up my mechanic and we noticed that the pulleys had bearing issues, so we replaced the pulleys and the belt just to make sure. For about an hour, there was no noise and then the noise came back. We both are stumped now and have no idea what it could be. I have question though; does the water pump make a noise as well if it is going bad? When we looked at the tensioner, we noticed that that pulley was bad too. My mechanic applied tension to the tensioner, and you could tell that the noise would stop as he applied tension and when he would hold back, the noise would come again, that is why i had the tensioner replaced. Now I am stumped. Any ideas?

 

Im definitely no expert here as I’m only just joined the forum but fortunately I’ve had that same issue with my old truck and it was the water pump. The bearing or something was dry and caused it to squeal. The reason my mechanic didn’t catch it earlier is the pulley wasn’t wobbling or anything like that. It felt tight but it was just dry bearing and it would have eventually worn down and started wobbling and possibly thrown a belt. Hope this helps and good luck with it.

 

If it’s the 3.5 ecoboost engine it could be turbo making that squealing noise. Mine did it under moderate acceleration. If it’s the 5.0 then there are several things it could be.