Does your Ford F150 emit a very annoying rattling noise when driving between 20-35 mph or accelerating at low speeds? Is the rattling sound audible at the very first part of the throttle or does it occur at any time irrespective if the engine temperature is at operational level or cold? Does the rattling noise come from the engine bay or can it be heard from the driver-side closer to the catalytic converter or transmission area?
Most Ford F150 trucks that experience these rattles are caused by a loose heat shield or loose heat shield clamps. The clamps become corroded over time and once the clamp breaks it simply hangs on the exhaust pipe causing a rattling noise under acceleration.
Many F150 owners report the noise to occur under any driving conditions and at any engine operating temperature. Whether your transmission is in (D)drive, (R)reverse, (N)neutral, (P)park, or even when accelerating from a stop, the rattle can be heard. LOVELY!!!!
Of course, the sound is not only annoying to the driver and occupants but also embarrassing as hell since owners even report that the rattle is audible to pedestrians walking on the sidewalk and apparently turn to see what it is. PHEW! embarrassing-much! Owners describe the metallic noise to be similar to that of a marble rattling in an empty can. NOT COOL!
Let’s now get into a few potential causes of this rattling noise.
Table of Contents
F150 Ecoboost Rattling Noise When Accelerating – Likely Causes
Below are a few potential causes of the annoying rattle during acceleration noise. We start with the easiest and least expensive to identify and repair.
Solution #1 – The Infamous Loose Heat Shield
Something as simple as a loose heat shield can cause all sorts of annoying rattles sounds since the shield is made from a very low-grade tinfoil-type aluminum. The shield can bend or dislodge rather easily once the clamps that are designed to secure it come loose. This causes either the metal clamp or the heat shield to, either rattle or makes contact with other metallic components around the engine.
Many F150 truck owners report a vibrating rattle which is extremely similar to the cam-phaser deceleration rattle. In that particular instance, it is mainly audible when the engine operation temperature is cold. Read more about that here.
Back to the heat shield!
So what actually happens to the heat shield and clamp?
As mentioned previously, over time the metal clamps that secure the heat shield become corroded and break causing them to hang or dangle on the exhaust pipe. Of course, since there is always vibration in the exhaust while idling or under acceleration results in a lovely rattle due between the two.
Where to check?
Inspect the driver and passengers’ side of the engine bay. Get underneath and give everything a good tug. Make sure you check the large heat shield that is bolted to the cross-member located somewhere above the exhaust section. Once the shield droops a bit it makes contact with the cross-member. There is also a thin heat shield that comes up just above the manifold on the driver’s side of the engine. At the back of the engine, just to the right of the wastegate, there is a thin piece of this heat shield that is basically hanging out past the wastegate.
Also, check for a clamp. It should be tightened around the shield on the driver’s side, it is welded on the passenger side. If the clamp becomes corroded and eventually broken you’ll have the infamous rattle-fest.
Solution #2 – 93 Octane Fuel vs 87
Then there’s your choice of fuel. Is your truck making a light pinging/knocking noise? In many cases running a lower-grade fuel won’t harm your vehicle, but it will result in less power and a decrease in gas mileage. In more serious cases, you may hear engine knocking or valve chatter caused by the fuel not igniting properly. These conditions could damage your engine and if you experience this, make the switch back to 91 or 93 Octane.
If your rattling noise is experienced mainly while accelerating lightly and you can hear the constant rattling noises until under heavier throttle, then it’s most likely caused by lower-grade fuel. This is because fuel with a higher octane rating can stand up to higher compression before it detonates. This means that the higher the octane rating, the lower the likelihood that detonation happens at the wrong time. Lower grade fuel, not so much.
Solution #4 IWE Check Valve
Many F150 owners are familiar with the well-known IWE CHECK VALVE VACUUM issue, which in most cases was caused by a dirty valve that doesn’t hold the vacuum 100% anymore. In this instance, the simple solution would be to remove and clean with a kerosene product a few times until the valve is able to hold the vacuum perfectly again. It’s that simple!
To test the vacuum using a vacuum pump. If you don’t own a vac pump I’m pretty sure you have a tongue … use it. To test it, suck the valve from the white end and see if it holds the vac using your tongue.
If after a few washes and sucks and it still isn’t able to hold vacuum 100%, replace the IWE check valve and solenoid. Job done. Get your Purge Valve on Amazon here.
(Watch) F150 Rattle When Blipping the Throttle [Video]
Why Does My F150 Rattle When I Start It – DIY SOLUTION
The next section explains in a bit more detail what happens with the cam phasers then we look at a quick 6-second DIY fix and later what real-world Gen 2 F150 Owners have to say about the rattle noise.
What are Cam Phasers and what job are they designed to do? Basically, Cam phasers are located in the head and are designed to lock at base timing after shutting down. Why is this important? It’s important because this allows time for oil pressure to build in the heads on the next cold start. How does this happen? The oil pressure unseats the locking pin and the PCM (Power Control Module) can then control the phaser position via the VCT solenoid.
What happens when the phasers don’t lock properly? When the phasers don’t properly lock, they rattle until there is sufficient oil pressure to fill the VCT unit.
Quick test: How to Perform the Extended Cranking
You can force the engine to build sufficient pressure by holding the gas pedal to the floor and simultaneously turning the key for about 6 seconds. Do this after a few hours of standing or on your first-morning start-up. By depressing the gas pedal and starting the ignition, it will swing the starter without allowing the engine actually starts.
What does this do? It will allow the engine to build enough oil pressure. After about 6 seconds, let off the gas and turn the key again. If you don’t hear the startup rattle then the problem is confirmed to be your cam phasers.
Ford F150 User Experience & Feedback
Let’s now look at a few real-world experiences from Ford F150 owners who’ve experienced the same vibration issue.
User Experience/Feedback #1
Do you have an F150 with the on/off throttle rattle and have already gone back to Ford and had the useless repair and then told it was a ‘normal characteristic’? What route are you taking?https://www.f150forum.com/f118/does-your-2017-f150-have-off-throttle-rattle-what-you-going-do-435865/
Please comment year, model, engine, build date, plant etc in the comment section. ie 2017 F150 XLT, 3.5 L ecoboost, July 2017, Kansas City
User Experience/Feedback #2
I purchased the truck in March 2018 and has been doing this (rattle under acceleration) since. Never noticed till about 5 months back when I drove my buddys truck which he bought 2 months after mine.https://www.f150forum.com/f118/2018-3-5-ecoboost-rattling-444818/
Once I noticed there was a serious problem with my truck I brought it to the dealership immediately where it went over for 3 visits a total of 3 months in total.
On the final visit without a tech from the supposed hotline that the onsite tech spoke too even being there present nor ever physically seeing the vehicle. They determined this was normal operations.
User Experience/Feedback #3
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.https://www.f150forum.com/f118/rattle-during-low-speeds-light-throttle-450782/
The funny thing is it actually mentions in the F150 owner’s manual that some noises like that every once in a while are normal.