6.0 Power Stroke EGR Valve

EGR System Overview

The exhaust gas recirculation system (EGR) is a critical emissions control feature integrated into the 6.0 Power Stroke diesel. Its purpose is to reduce tailpipe emissions of nitrous oxides (NOx), a family of gases found to be harmful. The process achieves lower NOx emissions by recycling a portion of exhaust gases through the intake of the engine and into the combustion chamber. NOx emissions are generated at higher rates when nitrogen is subjected to high temperatures in the presence of oxygen; the EGR system lowers the concentration of available oxygen in the combustion chamber and reduces peak combustion temperature.

Function of the EGR Valve

The rate of EGR flow into the intake manifold is controlled by the PCM and carried out by an actuator referred to as the EGR valve. On a 6.0 Power Stroke, the EGR valve is commanded between the open and closed states based on a duty cycle between 0 and 45%, with 0% corresponding to the fully closed position and 45% corresponding to a fully open state (maximum exhaust flow into the intake manifold). The presence of diesel soot in the exhaust stream presents a challenge for the EGR valve because this soot tends to collect on the valve, valve stem, and seats. Prolonged accumulation can impede the movement and function of the valve, which can result in delayed response (slow movement), a limited range of movement, or even cause the valve to become stuck in one position.

EGR Valve Service Recommendations

Clogged and/or stuck EGR valves are widely common on 6.0 Power Stroke engines. Note that the 6 liter was the first engine used by Ford that employed exhaust gas recirculation technology, and its integration into this engine is generally criticized as the result of the many repeated problems the system can be the subject of. Servicing the EGR valve is actually quite simple and straight-forward; remove and clean the valve, then reinstall it with a new gasket set. The process takes approximately 30 minutes for the average DIYer with moderate mechanical aptitude. It is not an advanced procedure by any means and requires only basic tools.

We strongly encourage that 6.0 Power Stroke owners service (or have serviced) the EGR valve at least every other oil change or once per year. In our experience, this is generally routine enough to avoid excessive soot buildup and clogging issues while also maximizing engine efficiency by preventing a fault with the movement of the valve. Note that modified engines may be more susceptible to EGR valve clogging conditions due to greater amounts of soot in the exhaust. For engines equipped with performance tuners or injector modifications consider servicing the EGR valve at every oil change interval - the same soot that is exiting the tailpipe is also passing through the EGR system.

EGR Valve Cleaning Methods

Once removed from the intake manifold, the EGR valve will need to be cleaned using manual methods. Small brass brushes and a solvent typically make quick work of the task. Acetone, mineral spirits, and brake cleaner all work well at attacking soot deposits. Do not allow any liquids to enter the body of the solenoid where the electronics are housed; concentrate all cleaning towards the mechanical valve apparatus. For stubborn deposits or heavy coking, the valve (again, NOT the housing) can be soaked in solvent over a period of time or between brushing. Wear eye protection and step away from the vehicle while brushing the EGR valve; soot may be flung profusely.

Parts List

[1] - EGR valve can be cleaned & reused; replace if not functioning
[2] - Includes mounting gasket and both o-rings
[3] - Inspect connector wires for chaffing and connector shroud for heat damage; replace as required
[4] - Replace if stripped or lost

EGR Valve Diagnostics

An EGR valve that sticks in the closed position (0% duty cycle) provides no EGR flow into the intake air stream. This condition can contribute to a turbocharger over-boost condition as well as excessive heat buildup in the EGR cooler. An EGR valve that sticks in the fully open position (45% duty cycle) provides maximum EGR flow into the incoming air stream. This condition is typically accompanied by increased soot exiting the tailpipe, rough idle, running rough at low engine speeds, poor throttle response, poor fuel economy, and low overall engine power. It is important to note that an EGR valve can become stuck in any position between the open and closed states. EGR valve faults on a 6.0 Power Stroke are intended to trigger one of the following DTCs:

• P0401 - Insufficient EGR flow detected. This generally corresponds to a valve that is stuck of sticking at or near the closed position, impeding flow.
• P0402 - Excessive EGR flow detected. This generally corresponds to a valve that is stuck or sticking at or near the open position, resulting in greater flow than commanded by the PCM.
• P0404 - Exhaust gas recirculation circuit range/performance. The root cause of this code can vary and it can accompany one of the aforementioned codes. It identifies that the EGR valve position is not corresponding with that commanded by the PCM. It can also indicate that the PCM has lost communication with the EGR valve, so electronic failures, shorted or open wire(s) in harness, or a bad connector are also all possibilities.

Note that cleaning an EGR valve will not repair an electronic failure. The devices can be tested using a diagnostic tool with the capability of accessing the special test integrated into the Power Stroke's on-board diagnostic system. Note that not every scan tool has this functionality, but some entry level diagnostic software suites (i.e. FORScan) can access these features. The Bosch ADS diagnostic tool is used in the procedures below to access and run this test.

• Connect the diagnostic tool to the vehicle (input appropriate parameters including vehicle make, model, year, etc).
• Once connected, start the engine.
• Locate the special tests section and select "EGR Duty Cycle".

• With the engine running, access the EGR duty cycle test and select "Start".
• The test will start with the EGR duty cycle commanded to 0%. Use the "Increase" button to command the duty cycle to 45%, corresponding with the fully opened position.

• The EGR duty cycle should promptly increase to match the commanded state.
• If the engine idle grows quieter and "duller" as the EGR valve duty cycle increases, the valve is functioning properly.
• If there is no change in engine sound and/or the EGR valve duty cycle does not move to 45%, the EGR valve is not functioning.
• Return the duty cycle to 0% and exit the test once complete.
• If the EGR valve is not functioning properly, the next step is to remove it for visual inspection.

How to Remove the EGR Valve on a 6.0 Power Stroke

• Disconnect both negative battery cables.
• Locate the EGR valve behind the intake horn, to the passenger side and below the oil filter housing.

• Remove the electrical connector from the EGR valve. The retaining clip is positioned at the rear of the connector; relieve the retaining tab, then pull straight upwards to remove.
• Inspect the connector terminals and wires for damage. If connector damage is suspected, it should be replaced.

• Locate the (2) EGR valve retaining bolts (identified with arrows in full-size image) at the base of the valve where it seats to the intake manifold.

• Tape an 8 mm deep socket to a socket extension to prevent dropping the socket into the engine valley.
• Loosen the EGR valve mounting bolts with the 8 mm socket. To avoid dropping the bolts into the engine valley, perform the last few rotations with long needle nose pliers or a good magnetic retrieval tool.

• Pry the body of the EGR valve upwards while pulling up and rocking side-to-side. A small 90° pry bar or flathead screwdriver with the tip bent 90° works well. Frequently alternate prying between the left and right sides to avoid damaging the valve. Do not pry on the mounting tabs, get a tool on the underside of the housing.

• While protecting the intake manifold passage from debris infiltration, clean the intake manifold EGR valve gasket mating surface.
• Use a shop vacuum with a narrow attachment to clean the inside of the EGR passage in the intake manifold. Often times, large chunks of soot fall off of the valve when it is removed. This debris could theoretically enter the intake passage in the cylinder head and prevent an intake valve from seating entirely.

• Inspect the EGR valve. Black soot buildup is entirely normal, but the presence of a white crystalline substance indicates engine coolant in the EGR system caused by an EGR cooler failure (crack).
• Remove the EGR valve gasket and (2) o-ring seals.

• Thoroughly clean the EGR valve with wire brushes and a solvent. Use a flathead screwdriver to manually actuate the valve assembly and clean the valve seats.

• Inspect the o-ring sealing surfaces; they must be clean and free of any defects to ensure a positive seal.

• Install the new EGR valve gasket.
• Lightly coat the new o-rings in clean engine oil. Carefully install the front o-ring first, followed by the rear.

• Lightly tape an EGR valve mounting bolt to the tip of an 8 mm socket for installation; this will prevent the bolt from falling into the engine valley.
• Reinstall the EGR valve and seat it by hand (firmly push downwards) before installing and tightening the bolts; do not seat the EGR valve using the mounting bolts.
• Frequently alternate between the left and right side mounting bolts, then torque each to 120 in-lbs.