The 20v 1.8t engine is an excellent unit and used in a huge range of VAG cars in various states of tune. I’d go for the 225 bhp version in a quattro TT plus the standard spec is better v’s the 180 bhp.
Main things with the 1.8t are:
– MAF sensor
– Coil Packs
– Water pump (original plastic impeller version would disintegrate, jam the pump and snap the cambelt – so check for regular belt and water pump changes)
– Regular servicing and oil changes with good quality oil are essential to ensuring the turbo is in the best possible shape.
These engines are very simple to tune and obtain big power gains, conversely doing so can shorten the life of a multitude of components. If you don’t want a modified one, make sure it hasn’t been. Can be tough to tell as remaps are the most common method and they can be ‘switched off’ so no way to tell if one had been used. However, remapped cars usually get other mods e.g. stainless exhaust, uprated diverter valve (standard item is plastic, modified will be alloy), induction kits, uprated intercoolers ,silicone hoses etc. Any evidence of these suggests a remap.
3.2 V6 looks and sounds better (especially with a full stainless exhaust), but I don’t think they offer much performance over the 225.