Hi all,

It's been a while since I have been on here. This was a great resource of knowledge for my previous trucks, hoping for some insight here.

'18 F150 in signature. I've owned it about two years. In that time, this has happened to me maybe six times. Under load, a sound will come from under the truck (around the transmission area) like a couple aluminum cans are trapped in the bell housing and are getting spun around by the torque converter. Sometimes I can let off the throttle and get back on and the noise is gone. Sometimes I have to slip the truck into neutral and back into drive to get the noise to stop. No correlation to temperature or gear. Tranny fluid looks good. Nothing noticeably loose on the driveshaft. Mechanic doesn't see anything. I can't reproduce the noise on demand. Truck seems to drive and shift normally. 4WD works. I don't think the truck has ever towed anything, there is no receiver on the back. It's a little over 110k on the clock.

It's incredibly difficult to troubleshoot something as random, infrequent and unpredictable as this. I'm hoping someone else battled this dragon and can point me in the right direction before I start blindly throwing parts at it.

 

Sounds like classic iwe symptoms. My guess, it is the check valve. If I was to blindly throw any part at such an infrequent issue, it would be p/n YG360, located by the brake booster. I have replaced mine 2x.

 

I'll check that solenoid out, but I am not sure the symptoms line up. When the noise is happening, it seems to change frequency with the engine RPM, not the truck speed. It goes away when I let off the power. And it doesn't sound like the noise is coming from the front wheels. I will check it out anyway. I think the solenoid is supposed to pull 15" in 2WD, correct?

 

I would also check to see if one end or the other of the cat heat shields has come loose. My nephew recently had this issue, and it was a broken tab on one of the cat heat shields.

 

I didn't consider that. Thanks.

 

I am not sure? There are videos on doing a complete iwe diagnosis.

 

More and more IWEs are failing as time goes by. They just aren’t designed well. Mine are very noisy lately, roaring like bad wheel bearings and sometimes rattling like bolts in a coffee can. When I pit it in 4 high, they get quiet.

This week I’ll check the wheel bearings to see if they are still good. If so, I’ll cap off the vacuum to the hubs. If the bearings are bad, I’ll just put new IWEs on.

 

I can't recall if I posted about my issues, but this problem sounds exactly like what I have happening, and it really doesn't seem to be the IWE. Cold as hell out right now, so I have been lazy about crawling under there ot find whatever is loose and rattling. Never happens at low speed, only when on the gas, not rolling or going downhill. @thomabb I'll see iff I had anotehr thread about this.

 

Looks like I have two different threads on this topic.
One posted sept 2023: https://www.ford-trucks.com/forums/1...way-speed.html
Other one from a few weeks ago: https://www.ford-trucks.com/forums/1...tle-sound.html

You can tell how infrequently I hear this sound by the fact that I've let it slide for a year and a half without getting too serious about the diagnosis. Don't think there's anything earthshattering in either of those threads, but always nice to have things to reference.

 

Thanks for that. Now I know I am not crazy, that's progress. I have found that when the noise starts, if I slip the truck into neutral and back into drive the noise almost always goes away.

 

Mine stops rattling the instant I take my foot off the gas, or the truck goes over the crest of the hill.

 

Same symptomology as I am experiencing. When i do the neutral slip trick then get back on the throttle the rattle doesn't come back.

 

If it's the IWE, just switching to 4WD (high or low) will stop it too.

 

Well, I was so fully certain that it was something under the truck like a heat sheild or something, but I was never able to find the culprit, and it's cold as heck here to be crawling around in the snow, so I kind of let this slide a while (again). However, teh noise cam back on my ten minute drive home recently, up a small hill in the city, so just for kicks, I switched into 4hi, which I was scared to do on the highway. Yeah, 4hi made the noise go away instantly, without me changing the throttle psoition or anything. Has happeneed a few more times recently, and yup, that works every time.

So, to everyone who said I should consider the IWE, you were right.

 

Could be the vacuum solenoid also, which is an easy fix.

On my truck the hubs will roar, and grind. I got sick of it and unplugged the vacuum solenoid. The left front hub is damaged. This is the only mechanical issue my truck ever had. It was taken in under warranty, they replaced the vacuum solenoid at 52k miles. It started doing this again about 4-5k miles ago. Warranty is long gone. So, next week both wheel bearing hubs get replaced, the vacuum actuators are going away, and RCV IWE eliminators are going in.