The new 6.4 Powerstroke engine had a lot to live up to. The Ford faithful jumped at the opportunity to get their hands on a new Power Stroke after a five-year production run of the 6.0L Power Stroke brought failure after failure to light. The 6.4L V8’s compound turbocharger arrangement, common-rail injection system, 350 horsepower and 650 lb-ft of torque looked impressive (and 550 to 600 horsepower could eventually be achieved with only a programmer), but the honeymoon was brief.

Between 150,000 and 200,000 miles, it is common for the engine to fail catastrophically. Many owners simply walk away from their trucks due to the high repair costs of a 6.4L (often double the cost of a 6.0L Power Stroke).

The following article will examine the 6.4L’s most notorious failure points and what you should be on the lookout for if you have one or are planning to buy one.

It’s time to pop a top (again)

In order to perform most major engine repairs, the cabs of the ’08-’10 Super Duty must be removed. While we agree with Ford that pulling the cab provides a technician with more workspace, allowing them to perform virtually any engine-related repair more efficiently, it does add four to eight hours of labor to the job (depending on which shop you use).

You can certainly tackle any of the following issues while the cab is still attached, but most techs prefer to do the work cab-off.

Particulate filter (DPF) for diesel engines

If we did not declare the emissions control devices to be largely responsible for the 6.4L’s reliability and performance issues, we would be remiss. The exhaust after treatment system, in particular the diesel particulate filter (DPF), is the focal point of several major failures. DPFs are designed to collect soot from an engine’s exhaust and convert it into fine ash. Without a regeneration mode, the DPF would quickly fill up with soot as it collects it.

Regeneration (also known as regen or exhaust filter cleaning) is achieved by burning the accumulated dirt particles in the DPF by turning a portion of the after-treatment system into an incinerator. During an engine’s exhaust stroke, fuel is injected (i.e. diesel leaves the exhaust valves, passes through the manifolds, turbochargers, and finally exits the exhaust system). It leads to higher exhaust gas temperatures, higher idle rpms, reduced power, lower fuel economy, and sometimes even smoke out the tailpipe.

It Is Unavoidable

The DPF will eventually plug and need to be replaced, just like any exhaust after treatment system behind a modern diesel engine. This component is prone to failure.

If the DPF is plugged, the truck will enter perpetual regeneration mode. This means that the engine is constantly exposed to exhaust gas temperatures of 1,200 to 1,400 degrees and extreme back pressure, which over time wears down everything from engine oil to turbochargers.

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