Ford's answers to the NHTSA 6.7 Investigation
There was a request for a link to Ford's answer's to the NHTSA investigation posted on a previous thread, since closed. Here is the link: Ford's NHTSA Answers to the 6.7 investigation This PDF i...
Forum Discussion
IMHO...the DLC is secondary to the main issue and that is that the
piston isn't captured positively to the cam follower AND that then
allows it to leave contact when the metering valve shuts off the
intake to the cylinder head
That then creates a vacuum in the cylinder head when the follower ramps down the
cam.
That then has the piston bottom leave contact with the follower
That then has the follower hammer into the bottom of the piston as it ramps up the cam
That alone is bad enough
Now add very poor lubrication qualities of a liquid that is fuel, not a lube
Add the very high PSI at the mating surfaces between cam, follower and piston bottom
Add the very poor cam cavity lube/fuel flow. To the point of stagnation in most
of the cavity where the fuel/lube recycles to even no flow, or
cycling the same fluid in the same area over and over
Finally, the organic acid that attacks DLC and H2O intrusion to create both
a brew component & cavitation.
Reducing the PSI/BAR telling on what 'they think' is 'the' or one of
the root cause(s)...but I think they will continue to miss it as
long as they have both the free floating piston and poor cam cavity fluid flow...
To me, baffling with the resources that Bosch 'must' have at their
disposal. Why or how are they missing the root cause(s) ???
I'm not a diesel guy and to me, plain as day the above issues and wonder
if there are even more (kinda sorta know there are and in the
distribution system...common rail...all the way to the injectors)
piston isn't captured positively to the cam follower AND that then
allows it to leave contact when the metering valve shuts off the
intake to the cylinder head
That then creates a vacuum in the cylinder head when the follower ramps down the
cam.
That then has the piston bottom leave contact with the follower
That then has the follower hammer into the bottom of the piston as it ramps up the cam
That alone is bad enough
Now add very poor lubrication qualities of a liquid that is fuel, not a lube
Add the very high PSI at the mating surfaces between cam, follower and piston bottom
Add the very poor cam cavity lube/fuel flow. To the point of stagnation in most
of the cavity where the fuel/lube recycles to even no flow, or
cycling the same fluid in the same area over and over
Finally, the organic acid that attacks DLC and H2O intrusion to create both
a brew component & cavitation.
Reducing the PSI/BAR telling on what 'they think' is 'the' or one of
the root cause(s)...but I think they will continue to miss it as
long as they have both the free floating piston and poor cam cavity fluid flow...
To me, baffling with the resources that Bosch 'must' have at their
disposal. Why or how are they missing the root cause(s) ???
I'm not a diesel guy and to me, plain as day the above issues and wonder
if there are even more (kinda sorta know there are and in the
distribution system...common rail...all the way to the injectors)
