So i am having an issue when i push on the gas at a certain load the engine is under it will make a grinding noise but once i let go of the gas it will go away. It seems like it is when the engine is under load or right before it wants to downshift. It is not constant, just when i have the gas at a certain position i guess you can say. Is their anything in the transmission that would make that noise? Would doing a transmission flush help as well? I also have a A/C compressor that is going as well and wonder if that could be linked to that but i am guessing not. If you followed my last post about grinding in my 4WD which turned out to be the IWE the sound is exactly like that! Please help me figure this out so i can know what it is and if it is something i need to fix right now or later.

 

Is it just at take off or when moving as well?

 

It seems to be a tuning issue to me.

 

not at all when i take off just when moving like going up a hill or when it is ready to downshift.

 

Put it 4WD and see if it does it ....

 

I just replaces both my IWE if this has to do with those again I'm going to be pissed!

 

If it's those again. then there's gotta be some issue causing them to fail. Trace it back further. Either that or you bought a crappy replacement set. BTW, when I had a grinding / whining sound under the hood, it was my A/C clutch. I replaced the whole compressor. It was cheap anyway.

 

My ac compressor is bad and I do need to replace it. I wonder if that's what's causing the noise because possibly the bearing are bad and when it is under load it is making that noise.

 

It's likely the check valves in your 4x4 vacuum system.

https://www.f150forum.com/f72/how-di...72/?styleid=14

 

Buy a no A/C belt and put that on and see what happens. It's only about $20 for a decent one.