I removed the air intake outlet tube (the one between the air filter and engine). It had a fine coating of oil inside and there was some minor puddling of oil sitting in the tube's creases. No oil present on or near the actual air filter.

Is this normal? If not, what is causing it and will it cause a major problem in the short term? What is the fix for it?

I also noticed oil (looked like leakage) around the rectangular base where the air intake tube seems to connect to the engine. What's going on here?

BTW - engine runs clean and does not blow excessive smoke except occasionally at start up you might briefly notice some smoke if its been sitting for a few days. There is some oil loss between my 6,000 mi. oil changes (I'm guessing perhaps a quart or two).

 

This is completely normal. The CCV does put oil into your intake system. As long as there isn't swimming pools worth of oil in your intake it should be fine

As for that rectangle box, that is where your CCV comes from the engine. There are o-rings in there that can be replaced to stop your leak

 

Thanks for the quick response. Should the air intake outlet tube be cleaned inside occasionally or just leave it?

I looked at the acronym page from the tech folder ... couldn't find CCV so I'm going to guess ... is it Crank Case Vent?

Also, is replacing the o-rings an urgent or difficult tough job? It's winter here in the Great White North and I prefer tackling this job in Spring if possible.

 

Depending on where your at in the country, the cold weather will increase some of the smoke we tend to see on start up. That being said, a lot of the guys here are very proactive with maintenance and with 150K plus miles will assume the injectors are ready for resealing, and or rebuilding. An increase in Oil consumption is always and indication of an issue. I'm sure Tugly/ Rich, who is a very knowledgeable guy around here will be along shortly and tell you to do a compression test and a couple of other routine checks to ensure the condition of the engine and or Injectors. We are driving 14-17 yr old trucks with some high miles, so it's important to pay attention to maintenance schedules.
The following is of course is you see excessive smoke at idle or under acceleration.
1. Blue/Gray smoke: Oil being burned
2. Gray/White smoke: is coolant in the exhaust system.
3. Black smoke: is an indication of excessive fuel.
The exhaust smoke your exhibiting sounds completely normal though. Just my opinion. Hopefully this helps yah some.
On edit; a Dirty Air filter will cause some oil consumption, something I feel that some folks tend forget to do or check because we've pushed towards longer oil drain intervals with running sythetics.