I have a 2005 f350. It’s studded, egr delete, wicked wheel in the turbo, fass lift pump, and spinster diesel turbo piping. I’m running blessed performance tunes off of a sct x4 tuner. While driving down the road the veins in my turbo seem to start opening and closing at random. This only happens some times and nothing seems to cause it. It will just start doing it then stop. Changing my tune has no effect on it and my coolant and oil temps both spike when I’m having this issue. I just put a new vgt solenoid on it which produced no change in the behavior. While doing 70 down the highway my vgt duty cycle will go up to 85% and completly close the veins resulting in 40+ pounds of boost, then in an instant open up to 30% and my boost will fall of. It can jump all over the place as well cycling from 50 to 80 down to 40 and back up in the matter of a couple seconds.



The pickup can go from running amazing to having this issues in a matter of a second. I know the vgt duty cycle is just what the solenoid is trying to push and actually not what the veins are opened up to. However I can hear the difference in turbo noise as this number jumps around and makes my boost surge and fall off. I have no explanation for this and I’m out of ideas. Ive attached a picture of my tuner with my oil and coolant temp spiked and pictures of my old solenoid after I pulled it out. Please help

 

Any codes?

 

+1 on the codes question!

Also am easy thing to try is to unplug the EBP sensor and run it ....... just to see if the issues are still there w/ the sensor unplugged

 

I’ll give it a try in the morning and let you guys know. And I do have an exhaust back pressure code.

 

Let us know the code number (and if there are any other codes)

 

I have a P0427 and a P0606 but I believe the second code to be unrelated

 

Check the codes again. I don't think that P0427 is a diesel code. It certainly isn't an EBP code.

 

Sounds like the vanes are sticking in the turbo if the EBP is good. Either one should throw a code.

 

When I look up the code it says that it means the ebp isn’t working correctly

 

Well ok ........... but it isn't in Ford's list of 6.0L codes.

https://www.google.com/search?q=ford...hrome&ie=UTF-8

Now if you MEANT to say P0472 ................. that IS an EBP code.

 

Sorry about that. It is the P0472. I unplugged my ebp sensor and ran it. It didn’t have the same problems but my vgt duty cycle wouldn’t go above 50% so I take it my turbo was more relaxed. Do I try replacing the sensor and going from there or somthing else.

 

At KOEO, the EBP should be within 0.5 psi of Baro and MAP (KOEO). The book says within 1.5 psi, but IMO it should be close to identical (ie .5 psi).

That said, it sounds like you might need a new sensor. I would ONLY get a Motorcraft sensor.

 

I was having issues with a new EBP sensor reading wonky at times and I noticed the VGT would act strange, mostly at idle (cycling between 55 to 85 VGT). New sensor it's now much more consistent.

I believe the PCM uses the EBP as part of the VGT control.

 

Just picked up a motorcraft sensor. Gonna throw it in there and see what happens.

 

Wouldn’t hurt to clean out the tube leading to the manifold either.