5 minutes of real cloudy smoke and then 15 minutes of light smoke, in which i began gently revving the engine

 

It will smoke for a long time depending on ho much carbon is in the motor, most of the light smoke is the carbon burning off. I will say be carefull because a large bit of carbon can break off and get stuck between the valve and valve seat and do some damage, but I have only hear of this once or twice coming from a motor with 160K plus

 

It took my about 20 mins before I noticed it stopped. I would see a little smoke every time I started up the car for a few more days. I would say the best thing to do is go on a long drive of 30-60 mins to get all of the carbon deposits flushed out of the engine. Do a couple of hard pulls help as well.

 

Seafoaming the intake will foul up the spark plugs, so plan on changing them out after the seafoam.

 

How long do you run it in the oil before an oil change? 10 minutes at idle, 50 miles, or for 5000 miles (complete run of oil between changes)?

I will have to figure out the vacuum lines on my 2003 S8 4.2. I am almost at 80k miles and looking to change the plugs also.

 

eh, I don't see the point in running it through the oil. vacuum line should be fine.

 

In the oil, it helps break up oil sludge..

I would run it for 10-30 mins after the engine warms up, then immediately drain the oil. Do not drive the car with it in.

 

If you are really trying to get rid of the sludge that might be in the motor this is what you need to do did it on my 87 Jeep that had 180,000 on the I-6 worked wonders

http://www.auto-rx.com/index.html