yea, take it loose at the wheel. i did it with mine idling and i could feel the vacuum. if you dont feel it then your problem could be a busted or loose hose somewhere. you really need a pump to see if everything is holding that vacuum though. im gonna have to look around the house tomorrow to see if i have one, but im pretty sure my problem is the actuator.

 

I tested the vacuum with the "finger method" and I definitely felt some suction. What are your symptoms? If it is the actuator, how do you replace that? Where is the actuator located? I really don't think it is my bearings as it the sound only happens under certain circumstances - climbing hills or giving it some gas. Almost never hear it on the flats unless I am giving it some power like starting from a red light. If it was bearings, it would happen much more randomly.

 

the actuator is what the hose goes on behind the rotor. im not sure exactly how to change it but it should be simple. i think they cost $90 each at most dealerships. i only notice the noise at highway speeds, if i let off the gas or put it in 4wd the noise goes away.

 

Is it like a loud metal shaving kind of sound? When I bought my truck it was making that noise and I had a bad solenoid so I didn't even have 4x4. Now I fixed it by replacing the passenger actuator and IWE and I still have that noise. I am convinced that its bearings for me though because its happening both sides.

 

So you only hear it when you are putting load on the engine? Do you hear it specifically from the passanger side, or do you just know its up front?

BTW, do you have an aftermartket CAI or Gotts? Could it be a sucking sound coming from a leak in the intake?

If it was bearings, it would be more than just under load

 

the noise mine makes is kinda like if you were dragging a bag full of aluminum cans behind the truck, not quite as loud, but when i pass a car or next to a building i can hear it loud and clear. i mostly hear mine at the left front but that may just be because im on that side of the truck.

 

I found and fixed my problem. It was the 4 x 4 actuator. I also replace the solenoid but that didn't fix the issue - however it is a good idea to replace it as it is a bad design. The solenoid was $27 and took 2 minutes to replace. I tested the actutators and the right held a vacuum no problem but the left didn't hold any vacuum at all. Cost me $116 for a new one and with the right tools, replace it in about 45 minutes with the help of a buddy. Nice an quiet now!!

 

Well I thought I fixed my problem but as it turns out, it isn't 100% fixed. The sound is now gone as long as I am traveling on flat roads. If I am going up steep hills or pulling a trailer, the sound comes back. So, I determined I have a small leak somewhere else in the system as well. I have a feeling it is in the check valves as one doesn't seem to hold a vacuum. I checked with Ford and they will only sell the entire vacuum system. I just need the check valve. Anyone have a part number for me or any thoughts. I have tried the local auto parts stores but they didn't have one the right size.

Thanks!

 

it could also be the exhaust or manifolds or the shields or it could be bad cats

 

I just started having that problem going about 35+MPH when I accelerate it sounds like a tin rattle sound in the left front area. Once I let of the pedal it goes away. I haven't found anything loose yet. But it's pretty noticeable when I drive down the road and it rattles like that. It's a 2010 F 150 XLT 4x4 4.6 V8. The local shop said it would be a whole day job to figure it out. Starting with diagnostics 100 bucks and then labor for the whole day. It has a level lift and 35's tires on it. Any suggestions? The shop is pretty expensive, so I figured there would be some mechs out there who would have an idea. Thanks

 

maybe check the ball joints upper and lower? i think its worth to check...hey never know

hope you ll find the problem !

Jake

 

This thread is old but I have a truck I'm looking at has 150k is 2004 4wd and I would say the aluminum cans description sounds exactly like what I hear. The guy changed front shocks and I've yanked on all the possible parts most guys mention. Seems his noise is on rough roads mainly. My suspicion is the shaft that comes out to hubs from where driveshaft comes up to front to give front end power. I suspect there are bearings out and I'm guessing this is a common problem. The guy told me he was hearing a clunk clunk. The passenger side is tighter than driver's side so I hear rattle stronger from driver's side. I need to find a parts manual but if you grab the two pieces that look like two big circles bolted together and pick straight up and down you may find movement. Might take a prybar or screwdriver if bearing is still pretty tight but driver's side on mine clearly can be lifted up and down freely with bare hands.

 

I'm glad you found this thread because my truck is making the same freakin noise. 2005 4wd, replaced 4x4 actuator, that didn't change anything, and only hear it under acceleration above 35 mph and once I let off gas, it goes away. I saw someone ask if the OP had replaced the CIA and now that I think about it, my noise didn't start until after I installed an aftermarket Airaid cold intake. Maybe there is something to that. How can I test that theory? Reinstall?

 

You may be running too lean with that intake, and hearing spark knock.

 

Ok, did realize that while driving if I switch into 4wd the sound goes away, so has something to do with hubs or driveshaft. Wondering if guys without 4wd are also having this problem??