I got back form pushing snow at about midnight last night. I started my truck went in my buddies house for about 45 min and ate dinner.

Jumped in the truck to leave got, on the road and it had no power at all. You could stomp on it and the EGT would go up to about 850F and the boost was uncontrolled it went up to 38.7psi, I imediately let of and drove about 5 miles got to a place where I could turn it off. Then I restarted it and it was fine.

This is also while the outside temp was 13F. My tune is stock and my EGT runs about 500-650F and the max boost I have seen so far is around 26psi.

So what happened?

 

Some of the early '03s would "just do that sometimes." A "reboot" (key off, then restart) always fixed them. I'm 99% sure that all went away with one of the reflashes during 2003. So maybe you haven't got a very recent flash update... or maybe you just proved they didn't quite fix the problem?

Duncan

 

My flash was on 12-9-03. It has a flash number on it if that would be useful.

 

There is a more recent flash for yours. It is a good flash. I have it and really happy with it.

There are a couple of things that could have caused that problem with your boost and EGT. First that comes to mind is that your VGT actuator or vanes stuck closed, causing lots of boost. Without the exhaust flowing freely through the turbo, exhaust temps would go up. It could be a momentary failure of the exhaust pressure sensor or VGT actuator. If it happens again, I would have it checked out. Do you have modified exhaust?

 

Yes, I have 4" from the turbo out.

I really hate to have it flashed as the truck runs great and no tranny problems.

 

I have an opinion about modified exhaust and back pressure effects. This truck needs back pressure. The EP sensor feeds the PCM for the VGT actuator control.

 

Where would this EP sensor be located?

 

The EP sensor is on the end of a tube that comes off the driver side ehaust between the manifold and the turbo.

 

Yea Brian I brought this same problem up in a max boost convo. Mine buried the 35 psi auto meter. and you could hear the turbo spool up it was just under highway driving. no acceleration at the time. Mine has the latest flash. I also just installed the SCMT last monday and have drove it to detroit and back up to chicago racking up about 1180 miles on it in the last week and did not have a problem at all after putting the scmt on it. who knows... these truck have a mind of their own at times.

 

Go to the ...Tech Folder..... Read up on the 6.0 Bible. Read about the turbo and variable vanes. When the PCM senses low exhaust pressure, it closes the vanes of the turbo and focuses what exhaust is coming through on to the turbine wheel. So if you put a big downpipe, what exhaust is coming through the turbo excavates faster reducing the back pressure where the back pressure sensor is located. What happens, PCM says low back pressure close vanes. If you are cruising along and the vanes close, the turbo will speed up and cause more boost.

Why do you think Banks recommends the 3.5" down pipe for the 6.0?

 

my truck had no mods when it was doing it...

 

How about cat back changes or straight pipe cat back (no Muffler) could this cause the same problem?

 

you might have had some snow get into the air filter and freeze up. in the diesel manual it talks about this. On the 04's

 

I should have been more clear on that the truck had been sitting for about 24 hours while I had been out in another truck.

So there would not have been ice or snow in the filter, but I to had read about that.