If it was diesel smoke, I suspect it might have a black shade to it. It doesn't. Unfortunately the oil level is dropping at about a quart in probably 400 miles at best. I haven't had this on too many trips so the oil consumption is a bit of a guess. Maybe the engine is worn out at 127,545 miles.
I was thinking that a 25 year old engine might just have dried up and cracked valve guide seals.
I have heard of idi's going 300K. Maybe this one is not worth trying valve guide seals in before a major overhaul.
Then again, if the rings were shot, it would smoke under load going down the road and the oil pressure would be in the bottom of the gauge. Neither one of those seems to be true and with about 400 miles to a quart of oil, the seals might be worth a try.
I have seen some silicon exhaust guide seals and those piqued my interest. Intake seals seem to be all over the place but the Felpro name does get my attention based on the past. . . 45 years of experience of working with that brand name.
Then again, my diesel experience is in it's infancy and I am open to all suggestions. However, the oil usage, with the smoke at nearly every start up has me fairly well convinced that the engine needs the 25 year old valve seals replaced. I suspect the turbo with the increased cylinder pressure might, might have something else to do with it also.
So, if your in agreement, then what would you suggest for a simple vlave seal? Felpro? Other? Silicon? Other?
Or is 400 miles to a quart of oil and smoking like a banshee acceptable on these trucks?
Funny part is though, my '87 6.9 hardly smokes anything upon start up, cold or warm.
New glow plugs, filters, injectors and the relay at the tip of the ice berg.