Parts (replacement Samcos and a Sasquatch silicone airbox-to-turbo hose) arrived during the week. Despite getting our first sub-freezing night of the season last night, it was 70°F this afternoon, so I went ahead with replacing known and potential problem children.
Couple of notes:
Sasquatch's silicone airbox-to-turbo hose ships without an elbow for the CCV hose. This isn't a big deal, because in theory you can reuse the one attached to your OEM hose. However, when I got my OEM hose out, I noticed a crack in the elbow (yay, another air leak!) that I hadn't picked up on before. Replaced the elbow with a
Dorman 47043 unit from Autozone; it fit perfectly with plenty of space for hose clamps to bite into. No idea how longevity will be once it starts seeing some heat and vibration, but we'll see how it goes. FWIW, the crack was on the back side of the elbow, nearest the turbo heat shield. Makes sense that that would be the weakest point.
Double-checked the turbo impeller shaft while I was in there. It is absolutely dead-centre solid. As much as I'm looking for an excuse to upgrade the turbo, now is not the time to have to do that so I am
incredibly relieved for it to still be in good health.
The turbo-to-intercooler hose had definitely worn through where it was rubbing against the air pressure sensor. It was a small but significant tear, and it's obvious as to how that would have been impacting performance and economy. I am planning on doing WWDiesel's air pressure sensor relocation mod to the airbox lid in a couple of weeks, but as I'm heading out on yet another 2600-mile round-trip on Monday, don't want to do that one until I'm back home with a full complement of tools and a spare vehicle to drive
Have not replaced the intercooler-to-manifold hose; I'm housebound this evening while other things happen, so the time to undertake that just isn't here today.
Didn't have time for a proper test loop, but on a roughly 8-mile trip to Autozone and back to return an unnecessary PCV elbow I'd picked up, the KJ is much more responsive, especially in the idle-to-1600rpm range. Soot is very substantially reduced; waiting to see if a combination of the ECU relearning what the fuel/air mix is plus just blowing out any accumulated crud does on that front.
This is promising. There's nothing like finding one thing after another to add to frustration levels, but once visible progress is being made it feels awesome.
Related: based on the notes some of us have been comparing recently, I'm increasingly of the opinion that we need a tech article on what to replace / upgrade in the general vicinity of the intake, turbo, and vacuum systems. For those of us in North America (who never got the earlier or later CRDs), these are about to be 14- and 15-year-old vehicles, and it's clear that we're seeing driveability issues being caused by OEM parts aging out. Also, with many OEM replacement parts now falling into the category of 'good luck finding them', a sticky article describing what needs to be done in these areas in order to keep these vehicles running properly would be valuable. I'm willing to contribute to it if others are as well...