We took our 1991 HDJ81 (5spd) along the Alpine Loop in Colorado (elevation 8,000 ft to 13,000 ft) a couple weeks ago. Due to some of the steep, rocky sections coming down from both Engineer Pass (elev. 12,800 ft) and Cinnamon Pass (elev. 12,640 ft) I was in 1st or 2nd gear in 4Lo for awhile (20 minutes or more) to avoid riding the brakes. I noticed that while I was descending I was pushing out a fair amount of white exhaust smoke. The white smoke was embarrassing coming down. On flat or uphill sections where the engine was under load it took awhile for the white smoke to disappear. The white smoke finally disappeared after 10-15 minutes of driving under load.
With the high(er) elevations our 1HDT had a harder time and definitely generated more diesel exhaust (i.e. sooty) than normal, which is to be expected. We were careful not to push it too hard however. The truck has always had some blow-by and oil consumption has stayed fairly consistent, with less than 1L of oil consumed per 5,000 km to 7,000 km between oil changes.
Any idea what is going on? Should I be concerned?
On my research it seems that this white smoke is unburned diesel. I'm wondering if the higher elevations, combined with prolonged engine compression braking was causing unburned diesel to exit the exhaust. Thoughts?
With the high(er) elevations our 1HDT had a harder time and definitely generated more diesel exhaust (i.e. sooty) than normal, which is to be expected. We were careful not to push it too hard however. The truck has always had some blow-by and oil consumption has stayed fairly consistent, with less than 1L of oil consumed per 5,000 km to 7,000 km between oil changes.
Any idea what is going on? Should I be concerned?
On my research it seems that this white smoke is unburned diesel. I'm wondering if the higher elevations, combined with prolonged engine compression braking was causing unburned diesel to exit the exhaust. Thoughts?