metal grinding/scraping sound
 

So, my 2018 Scab 3.5 eco has about 6K miles on it since I purchased it in Feb. of this year. Build date was Oct. 2017. During this time, it has about 10 times made an awful metal scraping/grinding against metal noise. It is so wrong and awful even my wife will say, "What is that?!" And she has never heard any sound any vehicle has ever made. I wish I could get a recording of it, but it is so infrequent and most of those times I've been alone.

It's like one part is spinning against another or both are spinning. It happens only when the engine is cold and only within the first mile of being driven. The ambient air temperature doesn't seem to matter, but since the cooler fall weather it seems to be increasing in frequency. I'm not positive, but each time I have been able to hear it and notice, I am accelerating and the transmission is either shifting into 5th gear, is in 5th gear, or going from 5th to 6th.

It is not the let off the throttle rattle discussed in this thread (https://www.f150forum.com/f118/17-3-...rattle-401441/) though it also has this rattle.

If I let off the throttle, it stops. Give it gas, you hear it. Do this cycle once, sometimes twice or even three times may be needed, the sound will stop and it will not do it again for several hundred or a 1,000+ miles. Again, only when first started and within the first mile driven. I want to say there is some power loss, but it is such harsh sound, when I hear it, I immediately let off the throttle. There's a part of me that wants to step on the gas the next time I hear it, but I can't bring myself to do it.

Taking it in this week for an oil change, the frozen door latch Field Service and to have the trans. TSB done. I'm thinking they are going to tell me they cannot duplicate it, which I believe because it is so rare. Unfortunately, the previous Ford I owned was a Powershift Focus which also had lots of transmission issues. After many "cannot replicate issue" replies and transmission software flashes, Ford finally discovered faulty seals were leaking fluid onto the clutches. Once the seals were replaced it was okay. I don't want a repeat of that crap. This may be the last Ford I buy.

Other than this and the harsh shifting in general from time to time, I love this truck. It is the quietest, smoothest and best riding truck I've owned. Not a single rattle or squeak. Hopefully, they figure it out quickly andit's a once and done repair.

Any ideas what it might be? It seems definitely transmission related, but I suppose it could be something else.

Thanks for reading and chiming in.

4WD? If so, next time it is doing it, switch to 4H and see if it stops. If so, could be the check valve or the solenoid for the IWE hub engagement. Check valve is the easiest and least expensive thing to try. However, you should be able to get it replaced for free under warranty.

https://www.fordpartsgiant.com/parts...z-3a788-a.html
That is the Ford part you want to replace.
You have all the classic signs of the checkvalve for the 4X4 system going bad. What happens, vacuum holds the IWEs disconnected. When vacuum is lost, accelerating, the IWEs are trying to engage, and grind. Let off on gas, vacuum increases, pulling the IWEs to disengage.
Next time it does it, quickly throw it into 4H, bet the grinding stops.
I'll post a photo of the checkvalve and solenoid for you.
https://cimg0.ibsrv.net/gimg/www.f15...2b86ae733c.jpg
Checkvalve is that round white thingy. Follow the hose to the right, that's your solenoid.

Yes, let the dealer "try" and replicate the noise, but chances are, they won't be able to. "IF" you have a dealer with a tech that knows this system, and listens to you, he'll likely replace with the part number I linked.

You were right Wayne, it's getting to that time of year again.:D

The replacement check valve that most people use is Motorcraft YG360, about $10. If you search for "YG360" you will find a lot of threads about IWE noise. The tube assembly listed above contains the checkvalve, sometimes you can buy it for less than the cost of the checkvalve alone.

Like clock work. Weather starts getting cold, check valves start failing. To bad it isn't be cost effective for someone to build a better one. If it worked for the rest of the life of the truck, I'd pay 2 to 3 times what the current valve sells for. Be money well spent for the peace of mind for the life of the truck.

Yes, the YG360 was what I always recommended, until Ford came out with an updated part a few months ago. I can't say yet if it's better or not, but at least after 3 generations of trucks, it appears Ford finally recognized a problem.
In fact, in that photo, that's a YG360 in there.

Oh, you ain't kidding! So far, with my double valve setup using 2 YG360 valves, I'm still golden. Now having said that,,,,,,,,,,,,,,,,,,,:whistling2:

Wow . . . much appreciated BlueXLT, JohnDay and 75Ranger! I would have never suspected something like this. I'm happy to hear it is likely not transmission related. Now I know what IWE stands for. I have always wondered what all those IWE posts were about.

Now a couple of questions:
1. Given the truck is 7 months old should I be worried about any damage done to the IWE hubs?
2. Why would this part fail so quickly? It looks like a cheap piece of plastic, so maybe that explains it, but why not make it more durable as you guys suggest?
3. I've owned several 4WD trucks (a Ranger, 2 previous F150s, Nissan Pathfnder, etc.) I've never experienced this problem before. It sounds relatively common from what you describe. Is it just bad luck this time? The possibility of my cheap plastic check valve being made cheaper than the others that day?

Again, many thanks! This at least gives me some knowledge to bring to the dealer.