mechanics in here - what's my next step to find an intermittent drivetrain noise on F-150

[JaCobro]

Loose skid plates? Hard telling, not knowing. Lol. A video would help a bit.

 

[P49Y-CY]

I was going to guess u joints with no video or anything. Swap in your old driveshaft just to see Chris good luck.

Thanks Patrick, yeah I will try out the old driveshaft, and also double check the iwe's, and also see how bad the motor mounts move. I forgot that i took the driver's seat out last week to put on a new seat cover, so I won't be able to drive it until then anyway. But even if I can't get it figured out now it's not that big of a deal to me because this winter I'm planning to pull the whole drivetrain anyway and installing a reman 5.4. I just did that process on my STX so i learned a lot. And when I take it all apart I def should be able to find the culprit or figure it out.

But it's just weird that it started out of the blue like this when the truck was running just fine.

Does the truck have a level on it? Sometimes, they can get clunky sounding. Especially if worn ball joints and such.

no it is still on the stock suspension and wheels/tire size, but that would be a good idea for me to recheck the front end, thanks

Loose skid plates? Hard telling, not knowing. Lol. A video would help a bit.

i know, i am still living in the 1990's when it comes to this stuff lol. i gotta get with the program because a video would really make it so much easier. but negative on the skid plates, everything on the undercarriage feels real solid

 

[P49Y-CY]

i just wanted to follow up on this so that it shows what i think is the solution. (always hated seeing a thread that shows a problem but doesn't show how to fix it lol)

i'm pretty sure this is iwe-related. i've been driving it around again and it does seem to be coming from more near the front end/front wheel area. in the first minute of the attached video, fordtechmakuloco pretty much sums up exactly what i think happened. my noise is erratic, but it does seem to happen more under load, which is when the vacuum drops from the manifold. that plus me using the high pressure air and water to clean out the cowl area really makes sense that's how i messed something up. i don't have a water freezing problem, but i am sure that water must have gotten into this system and is causing vacuum problems. one of my first tests was the iwe's to see if the cv's were engaged/not engaged, but there are more tests i needed to do than just that.

this is my first four-wheel drive vehicle so i'm pretty much unfamiliar with the way this system works, but i am learning and hopefully i should be able to fix it.

thanks again very much for all your guys' feedback, i really appreciate it - cheers

 

[03cobra#694]

i just wanted to follow up on this so that it shows what i think is the solution. (always hated seeing a thread that shows a problem but doesn't show how to fix it lol)

Me too, thanks.

 

[2003RedfireVert]

FordTechMakuloco is the man. I hope you found your issue!