Two 06 6.0s With Different Problems

[lumberjack]

I have a 2006 F250 and a 2006 F550 that are giving me trouble. Both are 4wd and automatics.

The F250 has around 71.5k miles and has an intermittent start issue coming from low ICP. This started this week, noticed by a longer start time which quickly grew to a more prevalent (but still intermittent) no start/looong start. With cranking RPM's around 175rpm, sometimes the pressure will climb to the low/mid 300's and fire up. After the engine fires up, it runs normally, although at idle the IPR is in the mid 20 percentile vs the F550's percentile being in the teens. The max pressure I saw was 3400psi. Sometimes after killing it, it'll start back up without delay, it did 5 starts in a row today without trouble (waiting for ICP to bleed to 0psi, which it does quicker than my F550). It seems to be harder to get it to crank the first time than for subsequent restarts.

Undoubtedly I have a leak somewhere and I'd suspect the STC fitting. I have read about the air test, but haven't seen a clear protocol for this, anyone have a link to the procedure and expected outcomes?



Secondly is the F550 with 200.5k miles. It was in the dealer roughly 2k miles ago with a cracked injector cup. Under warranty they replaced the head and I paid for studs and BPD's EGR cooler. After ~1k miles the engine developed a very sporadic, very short miss occasionally at part throttle/light loads. The "miss" was originally a instant total loss of engine power that lasted under half a second. The people riding with me didn't perceive it. It made it out of warranty (Diesel Care Plus) by a whopping 154 miles before I made it back to the dealer. It is throwing two codes for the #2 and #6 glow plugs, but nothing related to the short/miss. The tech said it was either the PCM or the wiring harness, but it wouldn't hurt to drive on it and it shouldn't leave me stranded. Well, it hasn't left me stranded, but it has given me a 5 and 15 minute delay now.

The truck is throwing no codes (aside from the glow plugs). From cold, it starts right up like nothing is the matter and runs for 15-25 minutes before starting to "miss". It can sit and idle or drive down the road, either way the result is the same, a dead engine. The duration and frequency of the miss is no longer an occasional momentary blip at partial throttle, but it's still like the key is being cut off. I swapped the PCM from the F250 and killed the engine when I heard the first "miss," ruling out the PCM in my mind.

The FICM Logic Voltage varied from 11.5-13 volts during the miss/stumble/dying/restarting phase. The FICM main voltage stayed at 47.5-48V. After it dies, I can sometimes restart it with no problem, but now the more regular result is longer cranking/waiting/multiple tries (generating 6-800psi ICP during this time). I have bookmarked a couple PDF's with likely locations of chaffing which I will look at tomorrow. The ~15-25 minutes of flawless running makes me wonder about the wiring however. Is it possible to swap the F250's PCM and FICM to the F550 to test without issue?

FWIW, the dealership wanted $711.20 for the wiring harness and $1146.18 +$100 core for the PCM. Tousley's online price is $447.04/$880.44 respectively. They said $600 to replace the engine harness and an hour's labor to replace the PCM. Unless it's something spectacular, I'll likely do the work on both myself. The most likely exception is if the 250's problem is covered under the Diesel Care warranty and the parts/labor time to fix it make it worth buying the warranty.



Anyone have some guidance?

Thanks for your time,



Carl

[PowerstrokeTech82787]

Originally Posted by lumberjack

I have a 2006 F250 and a 2006 F550 that are giving me trouble. Both are 4wd and automatics.

The F250 has around 71.5k miles and has an intermittent start issue coming from low ICP. This started this week, noticed by a longer start time which quickly grew to a more prevalent (but still intermittent) no start/looong start. With cranking RPM's around 175rpm, sometimes the pressure will climb to the low/mid 300's and fire up. After the engine fires up, it runs normally, although at idle the IPR is in the mid 20 percentile vs the F550's percentile being in the teens. The max pressure I saw was 3400psi. Sometimes after killing it, it'll start back up without delay, it did 5 starts in a row today without trouble (waiting for ICP to bleed to 0psi, which it does quicker than my F550). It seems to be harder to get it to crank the first time than for subsequent restarts.

Undoubtedly I have a leak somewhere and I'd suspect the STC fitting. I have read about the air test, but haven't seen a clear protocol for this, anyone have a link to the procedure and expected outcomes?



Secondly is the F550 with 200.5k miles. It was in the dealer roughly 2k miles ago with a cracked injector cup. Under warranty they replaced the head and I paid for studs and BPD's EGR cooler. After ~1k miles the engine developed a very sporadic, very short miss occasionally at part throttle/light loads. The "miss" was originally a instant total loss of engine power that lasted under half a second. The people riding with me didn't perceive it. It made it out of warranty (Diesel Care Plus) by a whopping 154 miles before I made it back to the dealer. It is throwing two codes for the #2 and #6 glow plugs, but nothing related to the short/miss. The tech said it was either the PCM or the wiring harness, but it wouldn't hurt to drive on it and it shouldn't leave me stranded. Well, it hasn't left me stranded, but it has given me a 5 and 15 minute delay now.

The truck is throwing no codes (aside from the glow plugs). From cold, it starts right up like nothing is the matter and runs for 15-25 minutes before starting to "miss". It can sit and idle or drive down the road, either way the result is the same, a dead engine. The duration and frequency of the miss is no longer an occasional momentary blip at partial throttle, but it's still like the key is being cut off. I swapped the PCM from the F250 and killed the engine when I heard the first "miss," ruling out the PCM in my mind.

The FICM Logic Voltage varied from 11.5-13 volts during the miss/stumble/dying/restarting phase. The FICM main voltage stayed at 47.5-48V. After it dies, I can sometimes restart it with no problem, but now the more regular result is longer cranking/waiting/multiple tries (generating 6-800psi ICP during this time). I have bookmarked a couple PDF's with likely locations of chaffing which I will look at tomorrow. The ~15-25 minutes of flawless running makes me wonder about the wiring however. Is it possible to swap the F250's PCM and FICM to the F550 to test without issue?

FWIW, the dealership wanted $711.20 for the wiring harness and $1146.18 +$100 core for the PCM. Tousley's online price is $447.04/$880.44 respectively. They said $600 to replace the engine harness and an hour's labor to replace the PCM. Unless it's something spectacular, I'll likely do the work on both myself. The most likely exception is if the 250's problem is covered under the Diesel Care warranty and the parts/labor time to fix it make it worth buying the warranty.



Anyone have some guidance?

Thanks for your time,



Carl

If your going to solve your high pressure oil concern, That doesnt sound like an stc bracket, that sounds like dummy plugs and stand pipes. Believe me i had that happen countless times, and had one that in order to start it after it sat for 10 minutes was to unplug the icp sensor. When trucks are still under warranty i replace everything with all the updated components.
That sounds about right for the mileage for those to act up.

As for your missfire, have you done a cylinder contribution test and run the injector interrupter? Does it seem to miss at idle at all Or just on a small load?
That could be the signs of an STC fitting. I had what you are describing in an 07 with 98k on it. Could barely notice it, youd have to be a very finicky person to even notice it. But WOT thats when the miss would come alive. And thats where you could see ICP rise and start to fall down during the miss. Also found the ipr screen plugged. Cleaned it and replaced the STC fitting. Havent seen that truck back yet for anything other than an oil change and set of tires.

[PowerstrokeTech82787]

I do have a question for you though. Why do you think it is the PCM? Yeah they do go bad, i havent seen enough of them to rule it as a failure, or cause of your problem, thats a rare thing for me i dont know about other techs, but since 2006 i have yet to see them come in for a failed/corrupted pcm UNLESS it had that worthless Banks 6 gun system hooked up. They eat FICMs and PCMs like theres no tomorrow. And on a completley stock truck, i have seen maybe 3 out of 1000s that ive worked on that had a failed PCM.

Unless you have a code for the PCM i wouldnt go that route, pointless to throw money at something and not fix it...

[lumberjack]

Neither truck is throwing a code.

F250
Do you have a link to the testing procedure(s)? The truck won't crank with the sensor unplugged. I'd love to be able to narrow the leak down.


F550
The reason I suspect the PCM is because the tech at the local dealer said it's the PCM or the wiring harness.
I don't think it's HPO related on the F550, it's making the desired ICP with a low IPR %.

Can I swap both the FICM and the PCM from the 250 to the 550 to test without issue?

[Evil Eye]

FICM Logic is your running voltage going into the FICM and should be the exact same as your alternator output voltage. I would suspect you have an alternator problem, because it should maintain 13vdc. Low voltage can give all kinds of erratic readings/symptoms and can harm your FICM, so I would get it fixed as soon as you can.

As far as the F-250, I would agree that it sounds like a high pressure oil problem.

[lumberjack]

The voltage dropping is from me cranking it over trying to restart as whatever it is was actively causing the running problem. My point in listing the voltages was that the short/open wasn't on the supply side of the FICM.


I'm currently searching for the thread size on the ICP sensor for the air test for the F250.

[lumberjack]

On the F550 I fired it up and started checking various known chafe locations. I first checked by the ICP sensor, then jumped to the area between the FICM and the Turbo. Nearly as soon as I touched it (push/pull/squeeze, I don't remember) the engine died. I tried cranking the engine again, but to no avail.

I wiggled the wire bundle again and pushed in on the farthest forward connector and heard the injectors buzz. Tried cranking it again and it fired right up. I have pushed, pulled, and squeezed the bundles and connectors with it running without a stumble. It's still running at 1200rpm (high idle) going on 20 minutes now. It'd be awesome if all it was was an unlatched connector, although I didn't feel a destinctive click when I pushed it in.

I'll report back when the truck either dies or makes it another 40 minutes without stumbling.


On the F250, the sensor is a 12mm-1.5 thread. Hopefully the hydraulic shop will have something in that size in the morning, any other suggestions for a place to find a fitting for the air test locally? (Columbus, MS, fwiw).

[lumberjack]

It's still puring, going to back it back into its parking spot and take it for a test drive tomorrow.

[PowerstrokeTech82787]

Originally Posted by lumberjack

Neither truck is throwing a code.

F250
Do you have a link to the testing procedure(s)? The truck won't crank with the sensor unplugged. I'd love to be able to narrow the leak down.


F550
The reason I suspect the PCM is because the tech at the local dealer said it's the PCM or the wiring harness.
I don't think it's HPO related on the F550, it's making the desired ICP with a low IPR %.

Can I swap both the FICM and the PCM from the 250 to the 550 to test without issue?

No i dont but its an easy procedure, you will need a scan tool that is capable of output state command functions such as a snap on modis verus etc. What you do is remove the icp sensor, thread your adaptor in, remove the oil fill cap, and get in the truck command ipr to 85% put air to it then command it to 0% that way itll blow all the oil and make a passage, the 85% ipr is shut, at 0% its open. With that pressure and the ipr opening it will spray a mist of oil out of the fill cap of the oil fill tube. Buy a stethoscope from lisle specifically for finding vacuum leaks. I bought the same thing only with matco emblems on it. Now what your going to do is run the stethoscope from the drivers side valve cover front to back to the hpop cover, then to the pass side valve cover front to back. If you hear hissing, you have a leak itll sound like a air hose in the shop with a hole in it. IF theres NO leak you wont hear anything, if its a small leak like the dummy plugs, it will have the faintest hiss and as soon as you unplug the air line oil will come spraying out so take it off slowly or keep rags on the fender. (first time i ever did an air check i sprayed a sob service writer in the face who was standing next to the truck running his mouth to me) that shut him up. and sprayed the whole pass side of the truck with oil.

[lumberjack]

Yeah, that's the jist of what I've read online. Gotta see if I can make an adapter in the morning, hopefully I can whip something up.