DustinGBourbonnais

I cant find where a rattle is coming from and wondering if any other Ford Owners have found this

2015 XLT 3.5EB. Crew 5.5 box
49,000 miles

When driving between 20-35 mph I will let off the gas (all is good) then slight accelerate in which it does not down shift (Causing a slight bog down) there is a rattle. If I let off the gas it goes away. If I accelerate more it will go away.

That I can tell, it will only only do this during those lower sleeps.

A friend thought may be a heat shield but it could not find anything rubbing or loose.

Any Help?

Sirikenewtron

I'm dealing with a simular sound on my 2019 f150 3.5, it's only a small area of the throttle. I thought it was a heat shield rattle at first as well but it's not.. Does your sound sound like this?

F-ONEFIVEO

Mine is doing the exact same thing as the video also

elptxjc

Many trucks are doing that noise, which is extremely similar to the cam-phaser deceleration rattle when engine is cold. But instead, it happens when engine is hot, and during acceleration. It reportedly is coming from the transmission. It doesn't sound detrimental to me, but I'd keep an eye on it to see if it becomes worse. Since many trucks are doing it, I wouldn't waste my time with a dealer at this point, but look for one of those threads and read it, then add to it, until a fix (or cause) is found. Make sure to state how many miles on your truck, if you bought it new or used (if used, how many miles at purchase time), and any other relevant information. I'm going to try to duplicate that noise in my truck next time I use it, once I back it up into the garage, where any noises are amplified. I haven't heard anything, but just like with the cold rattle that I know it's there because heard it once, it might be there too. But contrary to the deceleration rattle (which all trucks reportedly have it), this one I think develops over time. I'll let you know. My truck has 7,300 miles, and now that I switched to Shell premium and M1 0/30 oil, it's running like a champ, and with no strange noises cold or hot. Good luck.

As a side comment, my truck was making similarly annoying noises too, but they sounded more like light pinging/knocking, and they went away with premium fuel, so I'm almost sure that was the cause. May I ask you if the noise is only when accelerating once, or constant while accelerating? Mine were constant while accelerating lightly, like on a freeway on-ramp surrounded by walls. I could hear the damn constant rattling sound until I got heavier on the throttle. How about yours? Haven't heard anything once I had full premium fuel in there (about the 3rd fill up). I'd try that before wasting your time and taking it in when there's no cure. Hope this helps.

Sirikenewtron

My rattle is only at the very first part of the throttle, it happens anytime hot or cold 24/7 in drive, reverse, neutral, park, when leaving from a stop.
My truck is a 19 with just under 5k miles, I only use shell 91.
As mentioned it's definitely not coming from the engine area like the off throttle rattle. My sound is coming from the driver side catalytic converter or transmission area.

I'm going to take mine in eventually mainly because the sound is embarrassing as hell, people walking down the street have actually turned to see what it was as I was leaving a stop.

legendarybc

Same rattle on my 2016 3.5EB XLT 302a. Just crossed 50k miles but first noticed it around 40k. Can’t find anything loose, but it sure sounds like it. I’m going to do a little bit more digging around during the next oil change.

Sirikenewtron

I'd be very interested if you find the cause of it.

Scott91370

The cause is in the title of the thread: Low Speed/Light Throttle.

Sirikenewtron

Got ourselves a comedian here. Don't quit your day job

legendarybc

I found the cause of my rattle. It was a loose heat shield, and not very obvious at all. I’m sorry that I did not take a picture, however this shield sits on top of the pipe where the exhaust runs from passenger side to driver side, and before it combines into a single pipe. This shield is welded on one side, but has a steel band clamp on the other. The clamp had rusted through, allowing it to rattle at a certain frequency. Because it is welded on, you wouldn’t think it was loose. But when I replaced the clamp on the other side, the rattle went away.