No 6.4 repairs to more than I can handle....

DieselD · February 13, 2008

So yeah go from none to a ton over night! First one has a blown up engine with 2 burnt pistons. From looking at the freeze frame this truck was a runaway for some unknown reason. best guess is and injector stuck wide open and away she went. either way ford is sending a new complete assembly line engine for it. I have the body off already and powertrain sitting on the floor do to being a ZF trans truck. who knows when my engine will be here

that was last week. now I have its sister truck(1 vin number off) and its got an oil leak. guess where? friggin bedplate!! yeah Im sure. checked all the normal suspects. so I get to tie up another rack with a body off.

lets not even count the dozens of radiator leaks Ive done!

Shlep · February 15, 2008

Isn't that the way it always go, we went through the same thing last week .....

Skidonenko · February 15, 2008

guess that throttlebody in the intake does not work

Jim Warman · February 15, 2008

If you are referring to it being used as a positive air shut off, it was never designed nor programmed for that function....

Brad Clayton · February 15, 2008

What is it's function?

Keith Browning · February 15, 2008

To reduce intake manifold pressure in order to increase EGR flow is how I came to understand it but the 6.4L literature states that the throttle body is used to assist with the exhaust aftertreatment system.

Tony302600 · February 15, 2008

I was told in class its suppost to prevent run-away's also. The PCM will see the uncommanded RPM spike and close the throttle valve.

Jim Warman · February 16, 2008

Tony... our technical training instructor took great pains to make sure that we saw this is not the case. Page 40 of the 6.4 coffee table book pretty much sums it up.

I vaguely recall a reference to the throttle plate "sweeping" at engine shutdown.... I don't recall what purpose this served but I do know that it has nothing to do with any air denial system.

If I get the time, I'll see if I can find anything in my notes.

Since we are in the heart of the Alberta oil patch, there was quite a bit of discussion regarding the EGRTP and positive air shut-off function. A runaway diesel sitting in the middle of a remote oilfield satellite could carry a very heavy liability... since some owners either can't service their trucks regularly or just can't seem to leave the friggin' things alone, Fords stance that it is NOT a PAS device is probably the wise choice, anyway.

lraffe1 · February 18, 2008

If I'am not mistakin the throttle plate opens when key is turned off. So if I'am correct it would be best to leave the key on instead of turning it off.

Jim Warman · February 18, 2008

If the engine is running away.... it ain't gonna matter....

FWIW, Roda Deaco makes a PAS valve set up for the 6.4. It isn't pretty to install and it doesn't make it any easier to work on the engine.

Alex Bruene · February 18, 2008

I remember originally being told in training that the throttle plate would act as a positive air shut off... but after a few weeks, my training instructor sent us all e-mails stating the information given was incorrect, and the thottle plate would not prevent a runaway, and would likely disintegrate during a runaway condition.

snw blue by you · February 24, 2008

Concerning throttle plate use, I have never believed it to be a PAS and it was explained as being used for EGR functions etc.

That being said, one of the first 6.4s that I worked on was an early build that had both a stuck open injector and an injector with a cracked boss (07-08-09) and freeze frame showed over 4000 rpm and if I remember correctly it also had a P0219 engine overspeed DTC.

When I spoke with the hotline they said the closure of the TP prevented the runaway.

So who is right? Does Ford even know, and if they can't get it right, what do any of us really know to be true except what we have seen and taught our selves?

BTW, I drained some 25+ qrts out of the pan and some 3-4 qrts out of the CAC.

Ford did a buy back, only 247 miles on the truck.

Tony302600 · February 25, 2008

When I spoke with the hotline they said the closure of the TP prevented the runaway.

HA!!!!!!!!! /forums/images/%%GRAEMLIN_URL%%/fouet3.gif

GregH · February 25, 2008

I could see why Ford would be wishy washy on this point. On the one hand, Ford shouldn't state that the TP will stop a runaway in addition to it's other duties. Otherwise, if the TP doesn't stop a runaway and there are lawsuits over it, Ford could be on the hook for damages.

However, the logic to command the TP closed is pretty simple. Compare RPM vs RPM_DSD and if they deviate more than (x) amount, kill the injectors and close the TP. If the TP is successful in stopping the engine, great. Disaster averted. If the TP is unsuccessful, then Ford backs up and says, "well, it wasn't designed for that anyway." What's the worst that will happen? The plate might break off and lodge furthur up the intake? Whoop de doo... The engine is probably doomed anyway...

Doesn't seems like much downside risk to command the TP to close, but don't admit that is one of the functions....

At least that's what it looks like from down here...

DieselD · March 3, 2008

as soon as those two get back on the road another comes in with a broken rocker arm. yeah and the cab was inpossible to get off due to an overhead rack loaded to the gills. cab on procedure sucks!

GregKneupper · April 27, 2008

I have also heard that the throttle plate is on there in case of a runaway. Of course i have not been able to verify this is true. But i do know that it is used during the regeneration process. Next time you get one that is in regen monitor mgp and egrtp pids and see what they do. It was strange the first time i saw a diesel with a negative mgp reading.