Ford's answers to the NHTSA 6.7 Investigation

[ricatic]

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 is over 20 pages long. There are some interesting statements contained in the documents. My favorite is the one where Ford says they buy the pump from Bosch as a "black box" and do no testing of the component. It is closely followed by the tantamount admission that the pump will not provide a long service life when exposed to the poor lubricity fuel found in the US. You will have to do the math using the sales versus failure tables for the US and Canadian trucks. Eye opening difference to say the least...

Regards

[BenK]

Agree and disagree

Disagree in that they will NOT talk, as there is too much money on the table. More
so in reference to the numbers or percentage of documented failures

I know these types, or was one of them in sheep's clothing. A technologist at
heart and tried or took that promotion thinking I could make a difference, but
so wrong in trying to be a bean counter. Just could NOT do it and one huge reason
got laid off the first chance my Ex-VP boss got.

It will either be a mandated recall or so much money leaving their table (bonuses
and options) that will 'force' those bean counters to do something.

Even then, most likely penny pinching to 'just enough' and not to solve, but to
placate whatever agency or public outcry (the public is NOT tech savvy and whatever
marketing verbiage works, will win out)

Personally think their hanging their hat on H2O is a misdirection and the general
public has swallowed it hook line and sinker

H2O can lead to a conducive environment for cavitation, which 'might' be a
leading cause of debris generation, but, IMHO, the real culprit is both the
poor or mistake choice of employing the fuel as the ONLY lubrication for the
cam cavity components and not securing the piston to the cam follower

H2O in the whole system has corrosion potentials, but I can not see how that
is the main issue with these pump failures. Again conducive to cavitation and
working with the organic amines on the DLC to become debris

The lack of a piston capture is plain dumb. No different than not capturing the
piston of an ICE. Heck, bet the PSI's are higher than any of our ICE's. Can you
imagine my big block's piston NOT being positively captured on the crank?!?!?
:S :S :S :S :S :S :S :S :S

The lack of a positive capture of the piston bottom to the cam follower
is then exacerbated by the way they managed deceleration/exhaust braking
with that metering valve/shut-off to the cylinder head. That creates
an even better separation of the piston bottom from the cam follower

Why, way back there, suggested to those who might consider disconnecting
that metering valve connection. Maybe that is the key, how much that
vehicle see's deceleration and that metering valve shutting off the
fuel flow

Once that piston bottom hammering the follower has enough cycles, it
then has debris spewed into that stagnant cavity, to further create
debris having those tiny bits in-between the piston bottom and follower
hammered some more

Everything else down stream is just that...down stream of the failure
point...the pump cam cavity. That is a secondary failure from debris
of the cam cavity failure

What is puzzling to me, is that the failure percentage is so small, for
now

This where I'm noodling other what if's...is/are there other contributing
factors?

H2O comes back but what is it about H2O in this fray ?

Is there a tolerance stack up condition that exacerbates the hammering?

Curious that the latest DLC posts says only one side of the union is
now plated... Is it that DLC on DLC not a good thing like I'm used to
with the other exotic coatings I'm familiar with ? Would a better lube
have solve that? Or better lube and proper flow solved that?

Back on the bean counter mentality...penny pinching will continue as
long as they make their quarterly bottom line (bonuses and options)

Only when a regulatory agency and/or public out cry forces their hand.
Then they will continue to penny pinch for a 'just good enough' solution...

[NewsW]

Coming to Conclusions

We are at the point where indisputable evidence of a problem is there.

Running design changes are normal, and should not be taken as anything but that --- a better way to do something that wasn't evident when a part is first conceived.

But what we have here is not evidence of a "running change", but a substantial, major rework of the pump --- that involve major retooling and is only slightly short of a "clean sheet" redesign.

Given the evidence at hand, I believe that the customers of this pump (and that is not the end user), but GM, Ford, VW, etc. should be quietly having a conversation with Bosch about covering their warranty costs, and with an agreement in place, addressing the units out in the field in a fair and equitable manner.

Since only a small percentage of pumps have been failing, a fair way to go about it is to extend the warranty on the CP4 pumps in the field to 150,000 miles /7 years or more, and the warranty extension shall include consequential damage.

Warranty coverage on pump failures should not be unreasonably denied, unless there is good evidence of misfueling (e.g. fuel sample with gasoline in excess of 25% by volume, DEF, or other evidence of contaminated fuel that squarely place the liability elsewhere).

Contamination in fuel cases should be handled in a fair manner with the benefit of doubt for the customer unless evidence of misfueling with DEF, or willful ignorance of Water in Fuel indicator or willful failure to maintain filters, etc. were found.

The above policy shall be retroactively applied as appropriate.

This problem has cast a shadow on many reputable brands, and it is time for the industry to put the issue behind them.

More drastic action, such as a recall of all units in the field, is at present, not warranted by the facts.

[Arizona1]

Weibull,

I sent you a PM. Please check it.

Thanks

[BenK]

That is one way and the form factor becomes an issue

If the cam cavity is closed and filled with a proper lube, the piston can bang
all it wants and it won't spew debris into the fuel flow.

The piston hammering will still be a failure issue though

Using the fuel also as the cam cavity lube is penny wise and pound foolishness

Tapping into the engine lube system is good potential and again, the
piston hammering issue will still be there

[NewsW]

Don't have the resources to build and run a model, but it more and more looks to me that if fuel was not used for the pump as lubricant, and a separate fuel / lubricating function is used (as with HD truck pumps), then much of the issue of fuel properties and contamination goes away --- as with cooling issues.

[BenK]

"....turbulence

flow

boundaries..."

It has to have

flow

in order to have both turbulence and a
boundary layer...{edit}well maybe a boundary layer can also be there
in a non-flow situation...also a stagnant situation can also have
turbulence if the cam is turning and the cavities fluid is stagnant

Turbulence is a good thing in reference to lubrication and boundary
layers not a good thing, as the lube will be recycled and the fresh
stuff passing by outside of that layer

I see it very similar to the cooling simulations we used to run
for our silicon based systems

Why I'm convinced that the cam cavity & piston interface are setup all wrong

Humorous side note on Computational Fluid Dynamics from a past life....huge argument
with Fluid Dynamist when he used it for a traffic flow discussion we were
having.

Finally got it through to him that his DB wasn't applicable to vehicle traffic
flow because the fluid molecules were allowed to bang into each other, push others
that had slowed due to contact with the walls of the path, etc...while with
auto's, they are NOT allowed to bang into slower moving in order to get them to
move with the flow... 🙂

[NewsW]

I am doing some reading on Computational Fluid Dynamics, and one key issue that jumped out is how hard it is to model phase change and turbulence flow boundaries.

Is that what is happening with the turbulence in the pump?

[BenK]

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)

[NewsW]

VW lowered their pressure to 1,600 bars on the new models, not known if the new redesigned pump will mean raising the pressure again.

We now know it does have something to do with the use of the coating, but without knowing why... that is still a good guess.

The magnitude of change is what got me.

New housing material, new cam, new specs / surface finish...

Not minor at all.

[NinerBikes]

NewsW wrote:

NinerBikes wrote:
New observations on Bosch HPFP's made in Slovakia versus Germany. Full of Pictures. Material changes used in manufacturing... time to find out what Bosch is doing for Ford version CP 4.2 pumps, more so, where are the replacements currently being produced? What country?

pump comparison

http://forums.tdiclub.com/showpost.php?p=3799956&postcount=1706

Here are some obvious differences in a Czech Made 2012 Passat Pump VS our "Regular" German 2.0 tdi Pumps:
.
1.) The Cam has a 0.058" (1.5mm) LONGER stroke.

Major design change, lengthening the stroke and altering the cam profile --- that is a change to reduce the bearing pressure.


2.) The Follower no longer has the coating on it and it is ground to a
much better surface finish. (dweisel already identified this, thanks.)

DLC coating issue.

Big --- and looks like we called that one right on from one of the first posts.

Coating we found to be reactive could have been the issue, but retention of DLC coating on one surface and the other metal suggest something else... discuss below.


Not clear in the pic, but am I right that the piston now do not have a DLC coating on the piston?

Any change in the bore?



3.) The Bearing Material is different and appears again, to have a
better surface finish.

Better the surface finish, the lower the friction.


4.) The pump cover plate is slightly different, only to allow easier
casting /machining.


5.) The Main body is also a different material. Looks more like a
hypereutectic cast material . (More silicon than regular cast
aluminum.)

Does that make the body lower friction and also shed less particles / corrode less given it gets water in it?


6.) The FCV is a different part Number.

Translated: "New and Improved".


7.) All surfaces are finished to a better standard.

.
Here are the similarities:
1.) Same design and principal.
2.) Same aluminum Bore and bore diameter.
3.) Same Diamond coated roller shoe and roller diameter.

[COLOR=]That suggest something not right with DLC coating on DLC coating contact but is OK metal on DLC.

But not an assessment of DLC corrosion per se.


4.) Same High pressure Plunger Diameter and Head with Valve.
5.) Same internal COV valve.
.

OK, what is so different?

DLC Coating on DLC Coating contact seem to be the problem here.

Lowering pressure, friction with new cam profile.

May have altered fluid dynamics properties.

Is there a fluid dynamics problem being solved?

Or is there a sacrificial material approach (using metal on one side) to prevent small damage from growing?

Could it be that DLC coating have different fluid dynamic properties and two surfaces that are DLC coated "shed" lubricant (diesel)?

Is it hydraulic shock?

Corrosion?

Cavitation?

Adhesion of diesel fuel / contaminants to DLC?

Electrostatic properties and contaminants?

Lots to think about.


But my immediate thought is a deal is being hatched once this pump is validated in enough customer hands.

Please PM me regarding the last sentence, ie what does this mean to me if I own a Jetta or Golf or Sportswagen TDI? VW quietly goes about replacing the failed units, or is it enough of a safety hazard that a full blown campaign /recall goes into effect to avoid the collateral damage the first 4 years of pumps ending in P/N 155 A create. My 2012 Passat is the newest version with the part number ending in 155 E.

This still means that I am a BETA tester... Thanks, Bosch.

My personal feelings are that every accountant, every Doctor, PHD or Engineer at Bosch that had a hand in this pump pricing, design, material selection, and development should take a long summer vacation in a Ford or a TDI driving from Florida to San Diego and back with their family, babies, and grand parents in the vehcle, so they can experience failure first hand in the summer heat, and worry about their vehicle and the rest of their family, all at the same time. Maybe then, they'll come up with a better idea. Better yet, laps aroudn the old Race Track in Death Valley, CA.

[NewsW]

NinerBikes wrote:
New observations on Bosch HPFP's made in Slovakia versus Germany. Full of Pictures. Material changes used in manufacturing... time to find out what Bosch is doing for Ford version CP 4.2 pumps, more so, where are the replacements currently being produced? What country?

pump comparison

http://forums.tdiclub.com/showpost.php?p=3799956&postcount=1706

Here are some obvious differences in a Czech Made 2012 Passat Pump VS our "Regular" German 2.0 tdi Pumps:
.
1.) The Cam has a 0.058" (1.5mm) LONGER stroke.

Major design change, lengthening the stroke and altering the cam profile --- that is a change to reduce the bearing pressure.


2.) The Follower no longer has the coating on it and it is ground to a
much better surface finish. (dweisel already identified this, thanks.)

DLC coating issue.

Big --- and looks like we called that one right on from one of the first posts.

Coating we found to be reactive could have been the issue, but retention of DLC coating on one surface and the other metal suggest something else... discuss below.


Not clear in the pic, but am I right that the piston now do not have a DLC coating on the piston?

Any change in the bore?



3.) The Bearing Material is different and appears again, to have a
better surface finish.

Better the surface finish, the lower the friction.


4.) The pump cover plate is slightly different, only to allow easier
casting /machining.


5.) The Main body is also a different material. Looks more like a
hypereutectic cast material . (More silicon than regular cast
aluminum.)

Does that make the body lower friction and also shed less particles / corrode less given it gets water in it?


6.) The FCV is a different part Number.

Translated: "New and Improved".


7.) All surfaces are finished to a better standard.

.
Here are the similarities:
1.) Same design and principal.
2.) Same aluminum Bore and bore diameter.
3.) Same Diamond coated roller shoe and roller diameter.

[COLOR=]That suggest something not right with DLC coating on DLC coating contact but is OK metal on DLC.

But not an assessment of DLC corrosion per se.


4.) Same High pressure Plunger Diameter and Head with Valve.
5.) Same internal COV valve.
.

OK, what is so different?

DLC Coating on DLC Coating contact seem to be the problem here.

Lowering pressure, friction with new cam profile.

May have altered fluid dynamics properties.

Is there a fluid dynamics problem being solved?

Or is there a sacrificial material approach (using metal on one side) to prevent small damage from growing?

Could it be that DLC coating have different fluid dynamic properties and two surfaces that are DLC coated "shed" lubricant (diesel)?

Is it hydraulic shock?

Corrosion?

Cavitation?

Adhesion of diesel fuel / contaminants to DLC?

Electrostatic properties and contaminants?

Lots to think about.


But my immediate thought is a deal is being hatched once this pump is validated in enough customer hands.

[The_Mad_Norsky]

Interesting NinerBikes. Hope springs eternal. Maybe they will eventually get this right.

For you folks that have to attend summer school in link posting, there is something called the Advance Post Form. Click there, and on top of the dialogue box, in a box with a big blue circle in it, is the link button. Click that and paste your address in and PRESTO! You have a link that works. Like this one

A copy and paste of NinerBikes link. :B

On a semi-related note, I did get a recall notice for my 2011 6.7L diesel. Despite hoping for good things, all I am going to get is a reprogram of the PCM and Nox Sensor Module and a possible replacement of the Nox sensor. :Z

Oh well.

[NinerBikes]

New observations on Bosch HPFP's made in Slovakia versus Germany. Full of Pictures. Material changes used in manufacturing... time to find out what Bosch is doing for Ford version CP 4.2 pumps, more so, where are the replacements currently being produced? What country?

pump comparison

http://forums.tdiclub.com/showpost.php?p=3799956&postcount=1706

[NewsW]

Update:

I am reviewing several state of the art Finite Modeling Analysis (FEA) tools, including one called Abaqus that is part of the Simula suite of tools.

http://www.3ds.com/products/simulia/portfolio/

Presumably, the pump was designed using a comparable set of tools or the same one.

Interesting the limitations of the FEA tools and how difficult it is to include Computational Fluid Dynamics (CFD) into it.

The gist is that operator skill and expertise is really critical to use the FEA tools, including fitting the mesh properly and then making certain judgments --- like where to put in a "flaw" so the parts bend right.

A question I have right off the bat is how a coating is modeled when it is so thin and the properties of the coating / underlying material may not be well characterized.

A very fine FEA mesh at the points of maximum expected stress need to be done, and the forces on it simulated.

A problem arise that the expected maximum stress locations may be quite different from the actual places --- when cavitation and hydraulic events are included, or the existence of particles.. contaminants... like water.


Don't know when I get my CFD simulation tool grand tour, to see what the limitations of that set of techniques are.

[NewsW]

On a side note, I had another fuel related problem today.

No start / hard start (eventually started, but took a lot of cranks).

No code, not even a "pending code" and nothing amiss... only likely source is vapor lock.

Last year, I solved the problem by unplugging the fuel heater.

What happens when we transition from winter to summer fuel --- the winter stuff just vaporize too easily.

Another reason why the more I think of how many problems we are having... the more I think we are not dealing with variability in fuel characteristics too well.


Update: went and unplugged the fuel heater... it worked last time.