My son picked up an inexpensive 2006 A4 with the 2.0T (147k miles), bpg engine. It had a host of coolant leaks, and did end up getting hot. It ran after that, but subsequently took on water in the cylinders and will not run now. I had a local mechanic look at it, and after opening the top (not pulled the head yet), he noted a lot of dirt and an indication that the previous owner had not taken very good care of it. He recommended replacement (he is not an Audi mechanic). My son is asking what would be wrong with pulling the head, making sure it is straight, having it planed if needed, and going back in with a new head gasket in addition to a new timing belt/water pump and tensioner. It ran fine before this, did not use any oil to speak of, and he believe would be much cheaper than a $1,200+ (before labor) used engine replacement. Body and interior is very good. Does it make sense to repair it and do some frequent oil changes and go, or is replacement better in the end? Timing belt did NOT break or slip, so timing should still be good.