Turning up a Detroit, help or hinder?

I would ask them to have it noted in the computer system that its a 14L so if anyone runs the vin it will show up.

I'd probably just push for a new tag.

If I was to look into buying your truck and the tag showed it was a 12.7L and you tell me its a 14L, I'd think you didn't know what you was talking about and run away from the deal. SO resale may be an issue....

 

Glad to hear you're back on the road after all that.

I'll add to what hammer166 said, having just paid my way through a host of similar drive complaints as your "sneeze" issue. I've been blessed to find a solid service tech that knows these 14L Detroits backward and forward.

The egr system is incredibly sensitive to leaks. Stressing the word "system." Most common are the gaskets connecting the egr valve to everything else. Less common, leaks in the egr crossover couplers and the lines connecting to the delta-p sensor. That throws off the delta-p sensor, which in turn helps the ecm decide where to set the turbo vanes.

Another problem area are the vvt and egr v-pods, which are the solenoids that drive the turbo vane actuator and egr. A lot of times they don't just fail and stop working, but instead get intermittently less responsive. The procedure to test it is such a rube goldberg that the tech usually replaces them if they look more than a few years old. The cost of the part is cheaper than the time to run the diagnostic. Due to location, replacing the wiring pigtail is usually a good idea while you're in there.

In any case, your symptom ought to eventually set either a vvt or an egr code giving the tech a place to start looking. Alternatively, you can keep an eye on those egr crossover couplers and use a spray bottle (glass cleaner works) to find leaks on the egr gaskets. Crawl up in there and look for soot/cracks in the exhaust manifold. On my '04, you could only see the cracks on the exhaust when it was hot. Once it cooled (and the cast iron shrank), the only evidence was a little soot along the crack. The v-pod isn't too expensive and is located below and behind the turbo, attached to the block. There are two, one for the vvt and the other for the egr. The delta-p sensor is up above the turbo, and is where the two small lines on the egr go up to. On my '05, the tech has already advised that the readings are close to out-of-range and recommended replacement. I'll either get them to hang it on the next PM or just buy one and do it myself. That truck also has leaking gaskets at the egr that will get fixed on the next PM as well.

The alternative is around $4-5k to get a non variable turbo plus an egr/vvt delete tune.

I know you've got the extenuating circumstance with the engine repairs you've already dealt with, along with an empty pocketbook to start chasing egr/vvt issues with. I'm just putting this out there to point out that there's value in knowing how this stuff works to avoid getting caught in the trap of parts hangers that take your money and time and never fix anything. On my '04, I spent about $1,500 at another shop fixing things that may have been legit on a 7 yr old high mile truck, but never solved my original drivability complaint. With the '05 I had already started working with an expert tech and consequently have saved thousands by fixing what's broke and not just guessing at it.

 

I set my cruise at 60mph.... and with a MBN C15 I still manage 6.2mpg pulling these John Deere equipment loads and gross steel back thru the hills. I think something is not right with the 'troit

BTW, I took a 670 grader up to Maine across 80/84 and I even managed 5.9mpg @ 65mph over the Poco's

 

Allstate Pete in New Philadelphia has a couple guys who can work on most anything. My ISX gets its best MPG if i keep it below 65 MPH. I don't think the bully dog is your answer. If it was my truck i would talk to Haney,he is a Cat guy but he can talk to PDI and maybe get your fuel economy up. It just seems to me that the tunes are too pricey. Guess i'm cheap! I agree with the mechanic that says let the motor get broken in,then your milage should improve. Pretty sure Hissong in Richfield has some pretty good Wrench's around also.