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The Emphasis is on helping each other with diagnostic assistance, encouragement and the sharing of information
that will ultimately help us all become better at what we do in a positive and professional forum.
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 October 19, 2006 EGR
valve coking and sticking is not uncommon for the 6.0L Power Stroke diesel engine. An EGR valve that is
coked-up, or clogged with carbon deposits, will reduce it's ability to allow exhaust gasses to flow
through it when it is opened ultimately reducing it's effectiveness. These deposits may also cause the
valve pintle to stick or operate slowly making accurate control of the valve impossible. Should these
conditions exist several driveability concerns may result. This includes lack of power, smoking, surging and
the check engine light may illuminate accompanied by DTC's P0401, P0402, P0404 or P1335. EGR valve
diagnosis may lead to the removal and inspection of the valve. The photo on the right is an example of a
clogged valve. Initially, the recommendation from the factory was to replace the valve if it is more than 50%
clogged. Cleaning the valve under any circumstance was NOT recommended or a supported practice until now.
Since then, TSB # 06-19-6 has been released with guidelines to clean and test the valve for proper operation.
If the valve shows signs of excessive coking the root cause of the coking must be identified and corrected.
Cleaning of the EGR bore and the intake manifold may also be required. See the article EGR Servicing
for more details.
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 Begin cleaning the
valve by scraping out the bulk of the carbon with a pick or small screwdriver and a stiff nylon brush. The
photo on the left also shows the weep holes indicated by the red arrow. DO NOT allow cleaning chemicals to
enter these holes as damage to the actuator and the seals will result. Holding the valve in an upright
position is a good method for keeping any chemicals or debris from entering the valve.
Remove the o-rings
and the gasket as indicated by the blue arrows in the photo to the right and discard them. Take care not to
gouge the o-ring grooves or damage the valve.
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Submerge the valve
in carburetor cleaner, Motorcraft part number PM-3, allowing the fluid level to only reach just below the
base of the actuator. This is where not allowing fluid into the weep holes is critical! The photo on the left
shows the maximum level the fluid should reach as indicated by the green arrow. Holding the valve open by
placing an object between the valve and seat will allow the cleaner to clean the seats of the valve. Soak the
valve as long as necessary to remove the remaining carbon. removing to clean with the nylon brush
occasionally will speed-up the process. Final cleaning may be done by rinsing the valve with Injector
Cleaner, Motorcraft Part number PM-2.
When clean, use
compressed air or wipe the valve dry. Install new o-rings and base gasket supplied in the o-ring kit, Ford
part number 3C3Z-9P455-AB, and re-install the valve. From this point, continue with
diagnostics, verify the valve range and movement, clear all codes and retest. If the valve fails the range
and movement test or otherwise fails electrically, replace the valve. Always road test the vehicle to verify
the repair.
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This article is only to provide information. It is hoped that it helps technicians in identifying possible
causes and assist in the quick diagnosis of the identified concern. This is not intended to replace any
official instructions, authorization or documentation of any Ford Motor Company Engineers, service manual,
TSB, Service Message or recall.
 FDDTS
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