Help needed

[Hursty55]

Hi new to the page and hoping for a little help and thanks in advance.
I've recently purchased a 2006 audi a4 2.0 tdi 140 it was a non runner and needed a new coolant flange. Replaced the Flange and got the car back up and running with new anti freeze and air lock removed. Now 3 weeks later I've taken it for mot test and 10 mins later car started to smoke and expansion tank is on minimum we toped it back up and smoke disappeared car passed mot. When I got home just over a mile I noticed expansion tank was again on minimum and again white smoke so I repeated the process but with this time the bottle pressurerised and it settled on maximum no need for water no im suffering with other symptoms
1 no hot air in cabin
2 pipes to heater matrix are some times hot or some times cold
3 water keeps going down to min and back upto max
4 car won't rev over 3500 rpm when driving and car temperature starts to rise but never over heats
The car has no oil in water and no water in oil is the symptoms signs of head gasket or egr cooler failure thanks for taking time to read

 

[NHN]

So when you say it keeps going min & max, is that without top ups now?

As if it doesn't need topping up anymore, would suggest blockage, hence heating/pipes isaue, maybe stat, etc, given this was the system you were working on for the car to run, did you check circulation, by removing a pipe?

 

[Hursty55]

Some times it will need a top up other times it pressures bk to max I have removed the top pipe in expansion tank and its returning water back up