Skip to Content

Worst 6.4 Powerstroke Years To Avoid

The 6.4 Powerstroke engine, which Ford introduced in 2008, presented some great features that surpassed that of its competitors. However, it didn’t last long due to the myriad of issues that came with it. 

The worst 6.4 Powerstroke year to avoid is 2008. Although the engines were only produced for three years, they all had issues — with the 2008 model being the worst. 

In this article, I’ll discuss the common problems associated with the 2008 6.4 Powerstroke. If you’re still using that engine, I have some troubleshooting tips to help fix some of these issues. 

Reasons To Avoid the 2008 6.4 Powerstroke Model

Steering Seizing Up

Many complained that the steering of the 2008 6.4 Powerstroke would suddenly seize up while the car is moving.

Since losing control of the steering wheel is dangerous, I think this is a strong enough reason to avoid the 2008 iteration of the engine. 

Poor Mileage

You’ll likely notice the 2008 6.4 Powerstroke’s poor mileage in heavy traffic. 

That’s because, throughout the combustion process, the diesel filters regulate the temperature of the combustion taking place. The filter requires a constant fuel supply to carry out this function, causing increased emissions. 

If the filter needs to perform this process too often to regulate the temperature (as what usually happens with the 6.4 Powerstroke), more fuel will be consumed, and the mileage will go down.

When you drive your car in heavy traffic, you’re forced to slow down your car and consume more fuel.   

Sadly, there’s no fix for this issue short of replacing your engine or vehicle. 

Other 6.4 Powerstroke Problems

I’ve highlighted the most common complaints against the 2008 6.4 Powerstroke. As I’ve noted, the models for the other years up to 2010 suffer from a host of other issues as well. 

Clogged EGR Coolers

The 6.4 Powerstroke engine has EGR coolers that help to bring down the temperature of hot exhaust gases rerouted by the valve of the EGR. 

The coolant used in this process can break down after a while and clog the cooler. Unfortunately, the 6.4 Powerstroke regularly experiences this problem. 

One surefire sign that this is happening (or has happened) is an increase in your engine’s temperature. Because you cannot unclog your cooler, the only option is to replace the failed part. Otherwise, your engine will be completely and permanently damaged. 

Problems With the Diesel Particulate Filter (DPF)

The diesel particulate filter (DPF) of a vehicle is intended to reduce emissions. In the 2008 6.4 Powerstroke engine, however, the emission ends up clogging the filter instead. 

A blocked filter can lead to several problems, including a decrease in turbo and engine efficiency. The engine would have problems removing exhaust fumes — which, in turn, puts more stress on other parts of the vehicle. 

Due to the pressure on the rear from the filter jams, the engine needs to work harder to eliminate exhaust gases, causing a loss of power in the vehicle. 

You may also experience DPF leakage and sensor failure. 

Acceleration Issue 

This is one really annoying problem the 6.4 Powerstroke engine has. If you drive a truck with an engine that has an acceleration issue, you can’t have a smooth or comfortable ride.

You may also experience smoking from the engine upon acceleration, which can get pretty bad.

Also, you may be trying to accelerate, and the engine just goes off. Since this is an issue with no known solution, it may be best to avoid the model completely. 

Fuel Contamination

When the engine is undergoing the regeneration process, diesel is injected into the exhaust stroke. The diesel then goes into the exhaust system and raises the Exhaust Gas Temperature (EGT), burning off the hydrocarbons from the DPF. 

When too much fuel mixes with engine oil, the capacity of the oil to cool and lubricate the engine becomes limited. Some engines have an extra injector to spray fuel directly into the exhaust of the engine, and the 6.4 Powerstroke doesn’t have that extra injector. 

So, what happens is that the fuel gets contaminated due to the leftover deposits that accumulate on the cylinder wall over time. 

Left unchecked, fuel contamination increases your risk of wear and tear on critical parts of the engine since the engine isn’t being lubricated properly.

Ultimately, this shortens the lifespan of the engine and causes you to rack up your repair or replacement bills. 

Leaking Radiator

Since the radiator tanks of 6.4 Powerstroke engines are made from plastic, they’re susceptible to cracks and leakages.

These tanks crack because of excessive vibrations from the engine, resulting in coolant leakage. The engine then overheats and gets damaged over time.

Leakage in Up-Pipe

Up-pipes are basic but critical components of the exhaust system of the 6.4 Powerstroke. Unfortunately, they’re also prone to breaking in the 2008 version.

As they accumulate miles and age, they become more prone to damage from the engine’s temperature and vibration cycles. 

You know that the gaskets have broken if you hear a loud whooshing sound from the engine. Additionally, there might also be heavy smoke from the engine compartment. 

Lack of Fuel Efficiency 

Although the 6.4 engine has been described as a powerhouse, it lacks fuel efficiency. This is largely due to the DPF.

During the process of active regeneration, diesel helps to increase the EGTs and clean the DPR. In other words, your fuel is used for something other than propelling the car forward. 

If you drive in heavy traffic, your vehicle would experience frequent active regeneration cycles, which cut down on fuel efficiency. 

Helpful Tips for Tackling These Common Problems 

Almost all of the issues with the 6.4 Powerstroke can’t be repaired. Since that’s the case, you’d think the best option is to throw away your engine and never look back.

But there are ways to manage existing issues before they go out of hand. 

Get a Radiator Support Bar

You can increase the lifespan of a radiator and prevent it from leaking by getting a radiator support bar. This tool adds rigidity and helps to prolong the coolant system. Specifically, the tool reduces the twisting and flexing of the front end of the radiator. 

If you have any Ford Super Duty models between 2008-2010 that use the 6.4 Powerstroke, you may want to consider the Evan-Fischer Radiator Support Bar (available on You can get a year’s worth of unlimited mileage warranty as long as you purchase this product from the right place. 

Check Your Engine Oil

To combat the issue of fuel contamination, check your engine oil with a dipstick at least once a week. As soon as it goes over the maximum oil capacity, change the oil and filter.

Although manufacturers often recommend 10,000 miles (16,093 km) before an oil change, you’ll want to reduce that by half with the 6.4 Powerstroke. You’ll want to change its oil and filter at 5,000-mile (8,047 km) intervals. 

Also, try to use only top-quality oil that’s up to or even more than OEM specifications. The Limxink Ford Engine oil (available on is an excellent example of an OEM spec product. It has a 5W-40 viscosity and is well-suited for Ford engines.

Install Accessories To Improve Fuel Efficiency

You may have heard that some people do away with their emissions devices altogether to improve fuel efficiency.

However, you should know that turning or deleting these devices is illegal for any vehicle registered and driven on a highway in the U.S.

That’s why you can’t use a turner and straight pipe exhaust, even though they can significantly increase your vehicle’s fuel efficiency. 

The best you can do is invest in accessories such as an aftermarket intercooler, cold air intake, or a programmer that doesn’t delete your emissions gadgets.

Many of these turners are now approved by agencies like the California Air Resources Board (CARB) and are emissions-compliant.  

For the 6.4 Powerstroke, I find that the Mishimoto MMINT-F2D-08KBK Performance Intercooler Kit (available on works best.

It’s designed specifically for your engine, and Mishimoto offers a lifetime warranty — which is great considering that fuel consumption is one of your vehicle’s biggest expenses. 

Purchase a Coolant Filtration System

To prevent your EGR cooler from clogging, you should invest in a coolant filtration system.

Since the breakdown of coolant is an inevitable part of the exhaust gas recirculation process, the coolant filtration system should help preserve the coolant’s quality and durability. 

I recommend the EVGATSAUTO Coolant Filtration System Filter Kit (available on It has everything you need to keep your cooler in good shape.

If you’re unsure how to use most (or all) of the components in the kit, you can contact their after-sales service. 

Apart from all this, there are ways to make it more reliable, I listed 8 ways to make the 6.4 Powerstroke more reliable in this post.

Final Thoughts

The 2008 6.4 Powerstroke is the worst Powerstroke model, and one you should avoid. However, all 6.4 Powerstroke models have issues, and you may find the best decision is to avoid the 6.4 Powerstroke entirely.