Common 6.4 Powerstroke Problems (Explained)

Ford continued improving its Power Stroke engine series to be much better and more efficient. The 6.0L succeeded the 7.3L but didn’t live up to the expectation, so the 6.4L was launched.

6.4 power stroke is the successor of the 6.0L model and was produced from 2008 to 2010 – just two years. It didn’t live up to expectations, but it was quite a powerful engine. This powerstroke engine produces up to 350HP straight out from the factory.

Well, like its predecessors, there are also some significant 6.4 Powerstroke problems you should be aware of before choosing it as the primary engine for your Ford truck or van.

Let’s discuss the various problems associated with 6.4 Powerstroke engines!

What is 6.4 Powerstroke?

The 6.4L Powerstroke was the first power stroke engine for Ford’s light trucks; it came with dual turbochargers straight out of the factory.

Being that Ford was trying to achieve an environmentally friendlier diesel engine, the 6.4L power stroke was equipped with a new Diesel Particulate Filter (DPF) to reduce emissions.

6.4 Power Stroke can handle elevated boost levels to produce higher horsepower and torque than its predecessors.

This engine’s stock horsepower and torque responses are 350 hp (261 kW) and 650 lb-ft (881 Nm), respectively, at the flywheel. Also, this power stoke engine had a compound VGT turbo system for better throttling.

Other noteworthy features of the 6.4L Powerstroke engine include OHV 4-valve train, a DPF, and dual EGR coolers, which all help to reduce exhaust gas temps by up to 1,000 degrees and reduce emissions.

See Also: Common 6.0 Powerstroke Problems

Common 6.4 Powerstroke Problems

Quite sadly, the 6.4L Power Stroke engine has the highest cost of service and repair parts compared to other models in the Powerstroke engine series.

Hereunder are the common problems.

1. EGR Cooler Failure

The EGR (Exhaust Gas Recirculation) cooler is one of the components that constantly fail. EGR cooler failures can cause the engine coolant to flow back into the cylinder even though the engine is off; this can lead to hydro-locking of the cylinder and possibly bending the piston connecting rods.

2. Turbo-Charger Bearing Seal Failure

Seal failures can cause leaks to occur in the engine. The turbocharger in the 6.4 power stroke typically has its bearing seal crack after some time.

This causes the engine oil to leak away through the cracks during the regeneration process that pushes high exhaust temperatures through the charger.

When this starts happening, the DPF could get clogged; thus, the engine may remain in regeneration mode. Also, if this is allowed to linger a while, the faulty bearing seal can trigger a complete engine failure due to insufficient lubrication.

Apparently, getting a new engine is one of the most expensive works to do on a vehicle.

3. Connecting Rods Problem

The connecting rods in the 6.4 power stroke do not have bronze bushings at the end where the piston wrist pin contacts with the connecting rod.

Without the bushings, the rod is prone to excessive wear after many miles, and this causes a loud noise while driving.

4. Piston Ring Failures

Again, the 6.4 Power Stroke engine is linked with piston ring failures, especially in 7 & 8 cylinders, and this happens because of the regeneration process. The regeneration process involves fuel being injected during exhaust strokes to increase the exhaust temperature for DPF cleaning.

This process subjects the piston rings to excessive heat, which could cause them to fail (lose tension), thus, leading to low/no compression (also referred to as compression skip) and excessive blow-by. Piston rings failure is not an expensive fix, by the way.

5. Valve Train Problems

On lower-geared trucks with 6.4 power stroke, the rocker arm tips impact – caused due to higher pressure on the valve-train after about 100,000 miles can cause the valve-train to fail.

6. Cylinder Head Problems

The valve guides on the head gasket are unprotected (they do not have bronze sleeves), so they wear out quickly and allow oil to leak around the valves.

Also, if you install an aftermarket tuneup kit, it may affect the fuel injection timing, which could possibly result in cracking of the cylinder heads in the long run – due to extremely high combustion temperatures.

See Also: Common 7.3 Powerstroke Problems

What More?

Clearly, the most common 6.4 Powerstroke problems are a result of high mileage and aftermarket modifications. Also, the problems are major “cracks” and “leaks.”

These can be avoided if you keep up with a favorable maintenance schedule; this would allow you to detect the leaks, cracks, and failure signs early enough when they would cost so little to fix.

However, the 6.4L Power Stroke engine was short-lived because it wasn’t as reliable as expected. The 7.3 power stroke engines still remains the most powerful engine in the Power Stroke series, but it failed to pass the emissions test, which brought an end to its production.

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