need some advice.
328i/2000. After removing the old oil, I was only able to add 6 new quarts instead of about 6.75 quarts. I ran engine a while but it does not take any more.
Before removing oil I checked dip stick to confirm it was full. The oil extractor stopped removing old oil at about 5 1/2 liters. Checked dip stick and it was dry which led me to believe all oil was out.
Changed filter. It only took 6 quarts to full mark. I thought that maybe I had to wait for oil to go into filter for the extra 2/3 oil that I expected it to take.

So I conclude that there must have been close to a quart of old oil remaining in the pan after using oil extractor. (the extractor did start sucking aid when it was done) I noted that the tube from the pella 6000 does not flex when it hits bottom just straight in. Is it suppost to flex to go in more?

I watched the dealer do this using their oil extactor and it always takes about 6.75 of new oil, and removes about the same. The only explanation I have it the the oil pan had oil remaining and the pella 6000 tub is not flexible to go into to get the last 3/4 quart (but the dealers extractor tub must have been flexible.
Any other thoughts? Anyone change the tubing? With what type of tubbing.
(There is no question that the Pella tube was in as far as it would go, that both the dip stick and cleaned off Pella tube was dry after extracting the old oil --I used the pella tube after oil removal as a dip stick to confirm the pan was empty, and the car was on level ground)