The cam phaser issues were one of the main serious problems in the 3.5 EcoBoost engine in the F-150 and other Ford vehicles. Also, the older 5.4L engine was known for having this issue, but the 3.5 EcoBoost is the champion for phaser problems and I will focus today's article exactly on this engine.
Key features and my opinion about the 3.5L engine
- Production years:2010-now
- Average lifespan of 3.5L EcoBoost:190,000-220,000 miles
- Fuel supply type:direct injection
- Power range:310-660 hp
- Fuel efficiency:average
- Engine block material:aluminum
- Engine reliability score:medium
- The most common problems:intercooler problems, timing chain stretching, carbon buildup on intake valves, coolant and oil leaks.
Let's see what you can do!
What's the nature of cam phaser problems?
Usually, there are two reasons why cam phasers fail in the 3.5 EcoBoost powering your Ford F-150 truck: the phaser itself and the engine. In most cases, there is a combination of these two factors.
I'm saying this to make you think about total engine check instead of just phaser replacement. If you let the engine rattle with a bad phaser for a long time, I bet you now have problems with the timing chain. Prolonged vibrations affect the tensioner and the guides of the chain and I would strongly recommend replacing the entire chain kit when replacing the phaser.
Anyway, the initial reason for the phaser failure in the F-150 is obviously the poor design of the phaser. In the year 2021, Ford admitted the problem and updated the design of the phasers in the 3.5 EcoBoost. I can't tell you yet if the problem is completely solved but I haven't seen any phaser problem since the update was done. On the other hand, the new trucks still don't have a lot of miles on them, so it's too early to say something for sure.
When the camshaft phaser fails in your F-150 truck, it stops adjusting the position of the camshaft. So, it can't properly adjust the timing of the valves opening and closing and the engine may work harshly in a lot of situations. It's especially noticeable when the engine is cold.
How to solve the phaser problem?
Well, the obvious way to solve the problem is to use the new-design phasers. You can replace this part without replacing anything else. Unfortunately, the work is pretty labor intensive and you may also need to wait for some time till the part is delivered (the backorder problem keeps disappointing Ford owners).
I should say that the phaser alone may not save the situation and you will still need to think about the chain kit replacement. This is not cheap - depending on the chosen shop, this may cost you $2000 to $3000, parts and labor included.
But before you agree to pay that bill, you need to make sure there are problems exactly with the phaser and not with something else.
What else can cause rattling at a cold start?
Very often, the poorly maintained engine may do this. I mean the 3.5 EcoBoost will hate any other oil than what it's meant to use. Buy the Motorcraft oil - exactly the type that is written in the manual for your vehicle. Also, change it between 5000 and 7000 miles - this is the best interval for this engine.
If the oil is wrong, the cold start rattle may just mean that it's the dry start. Change the oil and filter and see if the problem goes away.
Also, rattling in these engines at high mileage is possible because of several other reasons connected with overall engine condition. Sometimes, it's cheaper to keep driving with the rattling engine. But if you want to keep that car for more than several months, you will need to pay attention to the issue.
But if you think that proper maintenance will help you prevent the phaser issue, you are wrong. This happens because of the bad phaser design.
Were there recalls for these problems?
Yes, Ford issued several recalls for EcoBoost phasers in 2018 and 2019. But Ford was criticized for not covering all the VINs and they didn't seem to correct that. Also, they issued a prolonged warranty for phasers in all F-150 trucks in 2021 but it ended in January 2023.
So, you may check your VIN in terms of recalls you may be eligible for. But, in most cases, Ford will not want to pay for the repairs.
Final thoughts
I know it's frustrating to understand that your F-150 may fail because of the manufacturer's mistake in the cam phaser design. But overall, the 3.5 EcoBoost engine is very reliable and durable. So, maybe, it's worth investing several thousand in it and installing the new-design camshaft phaser along with the new chain, guides, and tensioner. This will reportedly solve the rattle problem.
Before you do that, I ask you to make sure that the problem with your engine is exactly with the phaser. Use at least two repair shops to check the reason for rattling and don't agree to any repairs that may not solve the problem. Just tell the dealership or the shop that you won't pay if the repair doesn't solve the issue.
Any experience in solving the cam phaser problem in the F150? Please write in the comments!
About the authors
The CarAraC research team is composed of seasoned auto mechanics and automotive industry professionals, including individuals with advanced degrees and certifications in their field. Our team members boast prestigious credentials, reflecting their extensive knowledge and skills. These qualifications include: IMI: Institute of the Motor Industry, ASE-Certified Master Automobile Technicians; Coventry University, Graduate of MA in Automotive Journalism; Politecnico di Torino, Italy, MS Automotive Engineering; Ss. Cyril and Methodius University in Skopje, Mechanical University in Skopje; TOC Automotive College; DHA Suffa University, Department of Mechanical Engineering
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