If you are in the market for a 3.5 EcoBoost your budget and mileage will no doubt be two important factors to consider. So what if you find a decent deal on a 3.5 EcoBoost but the mileage seems a bit high? Is the 3.5 EcoBoost a reliable high mileage engine and how reliable are they once its seen north of 125 000 miles?
How many miles can you put on a 3.5 EcoBoost? A factory standard 3.5 EcoBoost engine can give you up to 250 000 miles (402 000 km), and more If the vehicle has been well looked after with regularly scheduled maintenance and no major modifications.
With that being said, it’s important to understand how the vehicle, you are about to purchase, has been looked after by its previous owner. Are there any signs of abuse? Has the vehicle undergone any major suspension lifts or tire modifications or has the engine been heavily tuned?
It is not highly recommended to purchase a used 3.5 EcoBoost with more than 125000 miles (201 km) on the clock. However, it also depends on how much you are willing to pay and how much risk you are prepared to take. Buying a used vehicle is always risky, a bit of a gamble since you never know what you’re really going to get until you know. The asking price of the truck should be directly proportioned to the overall condition and mileage.
So what is the general life expectancy on a 3.5 EcoBoost? Let’s find out!
3.5 EcoBoost Life Expectancy
We all know that hard use and abuse of most engines reduces longevity and reliability quickly. Also, major modifications like suspension lifts, bigger tires, heavy accessories and bumpers, engine tunes all decrease engine longevity since it needs to work a lot harder to haul the extra weight around even when unladen.
Even when you use the recommended oils and stick to the regular service intervals, you won’t make up for abuse if sustained regularly. However, if you look after your EcoBoost and treat it with respect, there is no reason why it shouldn’t reach 250 000 miles (400 000 km)
Now since the EcoBoost is a direct injection and forced induction, it is strongly recommended to change the engine oil at strict intervals and stick to the service schedule religiously. Make sure you use good synthetic oil that will help keep carbon build-up down to a minimum and. Doing intermittent oil changes every 5-6000 miles between scheduled services does the engine well too.
3.5 EcoBoost Reliability
EcoBoost was a major engineering and technological step for Ford. It is built Ford tough and is a sophisticated engine design that offers plenty of grunt to pull a load and runs silky smooth on the highway. It was a 6-cylinder that could perform like an 8-cylinder while using a lot less fuel. It’s a very well put together engine and fairly low on maintenance.
This direct fuel injection with dual overhead cams offers 365 HP & 420 TQ (Raptor’s 3.5L – 450 HP & 510 TQ). The beauty of it all is that the engine maintains 90% peak torque from only 1,700 RPM all the way to 5,000 RPM
Now that’s pretty decent if you ask me! Perfect for hauling heavy loads or towing. Good low down torque for going off-road too!
The only cause for concern with the 3.5 EcoBoost engine is with the direct injection. Direct fuel injection can cause excess carbon to build up on the valves which can harm engine performance. In 2018 Ford reviewed the design of both the 2.7L and 3.5L EcoBoost engine. Upgrades included a high pressure direct, low-pressure port hybrid fuel injection system which was designed to keep the valves clean and not allow excess carbon to build up. This improved engine longevity and reliability.
How Long Will an EcoBoost Engine Last
Like all Ford products, the EcoBoost is built Ford tough and is designed to last a long time. Both the 2.7 and the 3.5 engines are reported by many owners to reach well over 200 000 miles with only regular services and routine maintenance.
There is no exact amount of guaranteed miles on the EcoBoost, however many owners have made light modifications without any long term reliability side effects. Modifications include upgrades like intakes, exhaust upgrades, and mild engine tunes without compromising the reliability or longevity of these engines.
300 000 Mile EcoBoost
There are a few forum members who’s EcoBoost have even hit 300 000 miles without any major repair work. Owners claim the only repairs where a couple of throttle bodies that went belly up caused by the plastic gear that wore out. Other items include a transmission select sensors that failed. Oxygen sensors can also start playing up resulting in bad readings which will negatively affect your fuel consumption.
Other than that, one happy owner has reportedly reached 300 000 miles of problem-free EcoBoost smiles. Obviously, regular changing of the plugs and the scheduled oil changes keep the EcoBoost happy and reliable. Owners of these high milers recommend oil changes every 6-7k miles to keep the engine happy and healthy. Transmission oil and all fluids obviously also need to be changed around 150 000 miles.
Below is a link of an owner who’s 2011 EcoBoost reached 200 000 miles – have a look!
2.7 EcoBoost 200000 Miles
Turns out the 2.7 EcoBoost is built solid as a rock with more and more owners coming out and boasting about reaching 200 000 miles on these little engines. Again the main reliability issues were minimal in the form of a few sensors. Again, regular maintenance and the scheduled services are important and changing the oil every 10 000 miles with a decent full synthetic oil helps to keep the engine and turbo happy. However, it is recommended to carry out a 5000 mi oil change between services, since the 10 000 mi gap is a bit too long for the oil to maintain its viscosity and continue to protect the engine. Diff and transmission oils are also changed at 150 000 miles.
Obviously, if you are a road warrior and drive long distances every day it will be easier to rack up the mileage quicker without compromising reliability. One of the more common faults on these are the torque converters packing up. It appears to be a regular occurrence reported by owners on these trucks.
5.0 vs 3.5 EcoBoost MPG
The 3.5 Ecoboost is rated at 19 mpg combined (17 city, 23 hwy), the 5.0 V8 is rated at 18 mpg combined (16 city, 22 hwy). The fuel usage difference is only 1 mile per gallon.
The longevity of an engine is a funny concept actually because you get the one train of thought were owners baby the vehicle and refuse to tow but end up with heaps of issues. On the other hand, you get the same truck, living a hard life, being used on a construction site day in and day out 6 days a week with heavy tools, while towing a trailer, yet it racks up 200 000 mi easily. How is this possible?
The worst thing you can do to your EcoBoost engine is keeping it at high RPM for extended periods of time. This is because the peak stresses of the engine are when the piston is changing direction at the top and bottom of the stoke. The higher the engine RPM is spinning, the more force is applied to the internals like the crank, rods, and pistons during the deceleration and acceleration process. The force of the explosion actually counteracts the tension created by the piston being pulled down by the crank so the net force is less.
The EcoBoost has the advantage of having a lot of low down torque meaning it spends most of its life at relatively low RPMs, thus extending longevity.