Hello long time iv not been on this forum as iv not had a audi for around 7months as iv been partying in ibiza,but it was time to come back and buy a car, I was looking about for a few weeks and the audi a4 2.0tdi 140bhp b7 got me,seemed a nice looking car and very good on fuel, I took the car for a drive done a few of the checks you do and seemed all ok,just drove to manchester a 6 hour drive from me and all ok,the only thing I found out was the heaters was only blowing lukewarm air all fans not just the 1 side,The waterpump has been changed and the cambelt a few miles before this. I called the subaru garage who had done the work and gave them the invoice number so they could check if they had deffo done the job and to check was this problem like this before they started it,I got a call back from the person who fitted the pump and belt and my reply was the car came in with cold air blowing and we changed to pump and belt and a flush and seemed to be blowing abit warmer,but this is all what was said,I contacted the owner who i got the car off and got the old blag blag nah it worked for me and was running fine. So what I have is a problem that I need fixed as it is starting to get bloody cold..... I have read a few things on here about touching the rubber pipes near the battery and the bottom pipe is hot but the top pipe isnt, The temt gauge gets up to 90c and stays there at standstill or whiile going along as it should,the anti freeze was also just above min and after the 6hour drive abit under min,but now i have filled back up to max. Also when car is started or turned off the pipes coming off the coolant feel empty like just air inside them should this be like this.. whats the best things to check before I take this in to audi and cost me a bomb on cash. Any answers will be such a help thank you,any more information just ask I have tried to mention everything to help me and you guys to help me.