The Diesel Stop banner
1 - 5 of 5 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 · (Edited)
Hi Everyone. I'm a long time member, but I can't get into my old account. I've successfully repaired my 6.0 by searching this forum for many years, but the last few days have been a struggle trying to get my truck back on the road.

Update: it's a 2005 6.0 F350 with an automatic. The only modification I know of is an EGR delete that was done by the previous owner. Other than that it's a stock truck.

So for awhile now I have been having my truck go into limp mode and the dash wrench light symbol comes on. It started as a rare occurrence while towing and gradually got to the point that it would happen even when the truck was empty. A simple key off/on clears the limp mode and I can continue to drive. When I pull the codes it would always be P0234 Turbocharger Over Boost and P0299 Turbocharger Under Boost.

So I watched a ton of videos, researched on this forum and pulled the turbo to clean it. I did notice some minor wear on the unison ring, but I had to drive the truck in the morning so I put it back together with the original unison ring. The cleaning that made a big difference, but it would still go into limp mode once and a while and gradually it got worse again. I ordered a new unison ring and a VGT actuator last week and had planned to install them this weekend. But a few nights ago I pulled into traffic and tried to accelerate hard and the truck lost all power, and the dash boost gauge showed no boost. (and that’s odd, because usually I have to be carful not to over boost on a hard accel) No wrench light came on, no loud pop from a boost leak etc. I managed to get the truck home, but I couldn’t even reach the speed limit. I could hold it full throttle and even after 20 seconds there was no boost and I was hardly moving.

So I pulled the turbo, cleaned the veins and installed the new VGT actuator. On the bench I pulled the plug from the back side of the actuator passage and I could use a magnet to freely move the piston back and forth, and I could here the veins moving. Everything seemed to be operating smoothly.
I put the turbo back in the truck, went for a test run and it still had no power and it would not build any boost. So I did a pressure test and found the end cap of my intercooler leaking. So today I installed a new intercooler and redid the pressure test and everything was good and it held 25 psi.
So I figured great, I’ve got it this time. Well not so much, the truck still has no power and hardly accelerates. I held it full throttle and after almost 30 seconds I did manage to reach 70 mph and 17 psi boost, but the truck is still undrivable.
Recently the EBP sensor, EBP tube and fitting entering the manifold has been replaced. The turbo spins freely and I couldn’t feel and noticeable endplay. I checked the MAP sensor hose for cracks, checked my fuel pressure, ficm voltage, ICP pressure, disconnected the catalytic converter ect. I just don’t know what else to check.

MAP and EBP and BARO read 14.6-14.7 key on engine off
MAP read 38 psi when I did the pressure test, so it seems ok. (I replaced the MAP a few years ago)
FICM voltage is 49 Volts
ICP sensor PSI and IPR % seem reasonable (IPR never hits 15 or 85%)
MAF sensor values change as I accelerate (so I know its plugged in, not sure if the values are good)
Fuel Pressure is 65 PSI at WOT
VGT actuator and unison ring are new (and I can cycle the VGT actuator between 15 and 85 and I can here the exhaust sound change)

But my VGT is at 85% at idle, not sure why? I don’t have a tune on the truck (that I know of) my CAT is still disconnected, so I’m basically straight pipe after the turbo.(not sure if that affects it at all)

Update: I have reconnected the CAT and pressure tested the exhaust and I have no major leaks.

Here is a data log of my accel up to 70 mph, and it took 30 seconds. at the end of the pull, just before i let off the throttle
RPM was 3000
VGT %61
Manifold Absolute 32.73 PSI
Manifold Gauge 17.4 PSI
Exhust Back Pressure Absolute 36.1 PSI
BARO 14.35 PSI
IPR 75%
ICP 3792 PSI

(As you can see below I have times where the some sensors drop to zero and then come back. I assume this is an AutoEnginuity issue as I have had constant trouble with it since I bought it. It randomly stops working when I have it connected. Then I have to disconnect it from my OBDII port, restart the program, re connect to my truck and setup all the input I want to monitor again, so frustrating. Same thing happens when I use it on my buddies truck, and I have tried a different laptop also.)

Rectangle Slope Plot Font Line

Product Rectangle Slope Font Plot
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #2 ·
update, I just pressure tested the exhaust with a vacuum connected backwards (per Ford06's recommendations in another post). no major leaks that I could hear or see. So I soap tested all the joints and found a couple tiny leaks on the drivers exhaust manifold to head connection, but nothing that would effect anything.

Cheers
Cole
 

·
Registered
Joined
·
5,493 Posts
It would be helpful to know exactly what you are working on: Model year, present modifications, is the EGR and DOC present...
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #4 ·
Hi Ford_Doctor. Good point! Sorry I was so focused on the details I forgot the basics. 2005 F350 6.0 auto.

All stock other than an EGR delete. I'm also making the assumption that it is a stock tune, as I I haven't put a tune on it. I've owned the truck for the past 8 years and it seems to drive like a typical 6.0. but the EGR delete was done by the previous owner, so there's a possibility that the previous owner could have put a tune on it?

I assume DOC is Diesel oxidation catalyst? If so yes it is still in place (but I've never checked inside to see if it was hollowed out or anything)

Cheers
Cole
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
Update: FIXED!

I removed the "new" Ultra-Power VGT actuator and installed the old stock Garrett one and my truck runs perfect now! So just a warning to others. (I honestly had no idea that the actuator / veins could make the truck undriveable. Obviously I knew it would reduce the response of the turbo and have an impact on performance, I just didn't realize it could be that severe )

Hope this helps someone else.
Cole
 
1 - 5 of 5 Posts
Top