bought 08 6.4 113000 on it 4x4 lariet drove 300 miles home no proplem 2 days later runs fine for 45 minutes than loses power and sputters up hills starts no proplem every morning every time wait awhile sometimes runs fine was on e when test drove canged both fuel filters oil and drained 8 quarts tranny fluid and replaced it. when proplamatic rpms wont go over 2 turbo psi semms high seems in sync with rpms dropped a lot of dough help!

 

Maybe clogged dpf...Take it to someone who is a pro! Oh and you bought a used 6.4.. Thats a no no.

Welcome to the site

 

I own a 6.4L and really like it.

Trick question - regarding new OEM filters, which ones did you install FD4616 or FD4617?

Procedure question - Can you describe what you did to purge the air from the fuel filters?

Are you certain that the frame mounted fuel filter is fully seated?

Do you have a ODB scan tool capable of reading the DPF Back Presure Sensor and Exhaust Back Presure Sensor while driving? If you can do that then you can also see the DPF Regeneration Status to recognize if the motor is in process of regen or has completed the regen.

How much oil did you drain out? You need to monitor this....

What Oil did you put back in? How much?

2 on Turbo dash gage is actually 20psi which is what you would find for normal acceleration like getting onto the freeway.

 

iF YOU ARE LOSING BOOST ON THE SMALL GRANGE ON THE DASH YO SHOULD HAVE ONE. SOUNDS IT CAN BE A LOOSE OR BROKEN COLD INTAKE CLAMP OR A CRACKED COLD AIR INTAKE WERE IT RETURNS TO MANIFOLD.
FOLLOW PIPE AFTER TURBO DOWN TO THE INTERCOOLER. HERE THE NIPPLE COMING OUT OF INTERCOOER .THAT THE PIPE CONNECTS TO CAN GET OILY AND WITH PROPER BOOST BLOW OFF . AND ON THE OTHER SIDE OF THE INTERCOOLER SAME THING AND LOOK FOR A CRACK OR HOLE. GOOD LUCK
iF YOU JUST CHANGED YOUR FUEL FILTERS REMOVE AND CHECK O RING IS SEATED CORRECTLY AND THEN TIGHTEN CORRECTLY VERY TIGHT. YOU MAY JUST HAVE BAD FUEL AND FILTERS ARE WORKING AND CLOGGING. AND AS OTHER MEMBERS STATES I WOULD ONLY USE FORD FILTERS