Agree with replacing breather valve. Ever since 100 000 kms my 3.0d has become steadily smokier, and last week started spewing out a James Bond-style smoke screen even on light throttle. It did get rid of tailgaters though!

The breather valve is located with the oil separator on top of the engine (under engine cover) and is best done by a pro. They tend to split or perish, and if not fixed can cause problems with the turbo. Getting it done asap will eliminate almost all smoking as the engine stops burning bypassed oil.

Modern diesels like these should not smoke much at all if properly serviced, and now she hardly puffs a smoke ring, even on max throttle! But sadly the tailgaters are back....

Your oil will be black almost instantly as stated above. Diesel oil always goes black very quickly. I have owned three diesel powered vehicles with motors ranging from a 7.3 liter ford V-8 to a Chevy Duramax (Isuzu) 6.4? liter to an 8.3 liter Cummins 6-cylinder (motorhome). Sadly, I currently own no diesel at this moment.

Many things can cause black smoke from a diesel. My 7.3 Ford had a 4 position custom made "chip" that I could change fueling and boost settings on the fly. Settings were: Emissions Test, Economy, Towing, and Global Warming! On the last setting, I could blot out the sun at full throttle. That was fun to do to tailgaters, especially when they were in convertibles.

Modern diesels should not put out black smoke for more than the briefest of instants. I would look into the repair the previous posters noted. Something isn't right if you are blowing black smoke every time you accelerate (unless you have a custom tune set to global warming that is).

That doesn't seem unreasonable for a 3.0d (640miles ~ 1020km).

The 4.4 is an absolute pig when it comes to fuel, I get about half of what a 3.0d would get in terms of mileage.

Its located on the top part of the engine beside the air filter.its at the back end of the filter.Its about 6-8 inches long and has 3-4 allen key bolts holding it in.It is one complete piece with a round section narrowing to a square piece.

It has a filter in it for the oil.Should be changed on each service(I do)
If not changed could blow your turbo.

My filter inside was rock hard with oil ,once chnage runs like a dream.
Hope i explained on.They are 35 euro so cheap as chips

Romal