Mine coasts along between 10 and 20, but will approach 40 in a hard pull. I have plenty of power. I have noticed when it's in REGEN that the boost seldom betters 20, however.

 

Caprang.

Wonder if you are having DPF problems again? You already had one replaced. How do the pipes look? Just throwing my 2 cents in.

 

If I am driving normally, I seem to have plenty of power 1st thru 3rd gear, when transmission shifts into 4th there seems to be some lag and not as much power, when it shifts into 5th the truck almost seems to lung ahead. When I get on it, power seems strong thru all gears.

 

I'v seen 35psi maybe a little more, mines a job 3 all stock with the reflash. I've only had one time that the boost wouldn't come up and it was regennnning. Otherwise it's plenty-o-power.

 

Tailpipes look great (knock on wood). I havent gone on a trip of more than 25 miles since Christmas so maybe there is something with the regen going on. I checked the IC for that and it didnt show it. Since the reflash it didnt show it either but it was only a 10 mile drive home. If its due for a regen would 20 miles of hwy driving at least initiate it? Admittedly all the regens (that I have noticed) have occured on long drives of 100 miles or more. Maybe 20-25 miles isnt enough time to get it hot enough to regen? Seems fitting that the performance and boost would be down if the DPF is clogging up.

 

Putting the truck in gear and driving out the driveway will start a REGEN if the sensors are calling for it.

 

does need to be up to operating temp for it to regen. seems to me that if it gets bad enough it will go in a mandatory regen, the message changes from "cleaning exhaust filter" to a message of something like " drive to clean exhaust filter". Don't quote me on the exact wording.

 

I believe you are correct on that.

 

Brand new it seemed my truck would max at 32psi if I was getting on it without a trailer. Now it seems rare to get over 30. Anything more than 32 is EXTREMELY rare even while towing. I did see a sustained SOLID 40psi for a few minutes when climbing a hill with a small utility trailer attached, but that was probably a year+ ago. Pulling about 7k pounds now doesn't seem to get me anywhere near that.

 

Caprang, my experience is very similar to yours. When I am towing anywhere from 5K to 15K my boost guage never reads higher than 30. I just drove approx. 1500 miles in the past three days and watched things, I had a 16ft cargo trailer with about 3K of gear in it, so it was very reasonable in the weight. I would say it is enough weight to warrant some attention from the turbo.

Generally, interstate on ramps are tough. I have to seriously stand on it to get up to 70 so that I can merge without screwing up other people. Generally, I hit the interstate at around 60 and take some time getting to 70. This is using a decent amount of pedal but not all the way down. My boost never goes above 30 through any of this, uphill or down hill.

Cruising the interstate, an average grade will not cause my motor to upshift and the boost will rise slowly to 30 to help out, on flat ground maintaining 70 my boost is probably around 10-12.

A decent grade will cause an upshift to 3000-3200 rpm and a boost pressure of 30, maybe 32 if you hold your head right. This is where it gets interesting. On humid/rainy days my motor will stutter as if it is reaching a rev-limiter. On colder/dry days this does not happen and I get a real surge in power when the upshift happens. On humid days the upshift is a mild event resulting in very little accelleration and just a maintaining of speed.

I have checked the air filter restriction gauge frequently and it never gets tripped, water separator is drained, correct fuel used, latest flash, and perfect maintenance record.

I suspect that the humidity issue is something you may share being in FL (I think I read that).

With the dense 60 degree weather today in the South I had a lot of instances where the motor just refused to rear it's head and give me the hard power. BTW, I drove around 500 miles today monitoring this. FYI, I had regen cycles @ a rate of 1 per tank of fuel. I had one episode of an upshift event, needing power to get uphill and speed up, and not only was my motor stuttering, it poured out white smoke for about 5 sec. This was merging onto I-285 in ATL from I-20 eastbound. A very short ramp, one of those 25MPH clover leaf's.

I have A LOT to say about this but pretty much just accept the "quirks" of the motor and don't really make anything of it.

I am happy to make something of it here though, it'd be great to learn of something about all this stuff.

Another thing: We should look at the BMW diesel program as they have been using urea for a number of years now. I remember seeing it on Discovery channel a while back, before I got the '08 6.4, so I did'nt really pay much attention to the detail.

 

I do not have trouble passing with my new one I am 18500-26000 lbs most of time and do not seen to have troble it is like driving a good gas engine no lag

 

Caprang,

I bet that is it. I remember reading a previous post regarding someone's power reduction and it was due to his using his truck for just commuting to work at low speeds with no real highway travel.

Take that thing to the highway, put on some good tunes and take 'er for a good ride at 75mph for about 30 minutes. Bet the problem clears up.

Just my usual 2 cents. Good luck.

 

when mine was a bit slugish I hooked up a trailer loaded down and then took some hills at about 80.

 

Yep, I definitely think a road trip is in order. Sadly I have no where I need to be this time of year and the trailer is on jack stands for the winter. Maybe I can convince the wife that me and the boys need a week in Vegas to fix my truck.

 

Vegas hugh? I don't know how far that is for you to drive. If it is far you might want to start with something a little more suttle(like a trip to Wal- Mart) for the wife convincing and then let it grow into Vegas from there. Just my 2 cents.

Good luck. Let us know what happens and if your power comes back.