Audi A4 1.9 tdi 04 reg 130 sport question

[Vikki1972sean]

Hi everyone I'm new to this have couple of questions I.have an Audi A4 1.9 tdi 04 reg 130 sport I thought timing belt had snapped couple weeks ago but after inspection I found that about 2inch of the teeth are missing ,car turns over freely by hand with no lumps or tight spots also turns over on starter no different sounds to what it used to sound like , hoping no damage done , I was also wondering if timing belt off a3 2.0 tdi 61 reg will fit as just been given one to try but don't want to strip it all out if not or if poss to much damage done I'm hoping someone might no thanks sean