Tomshep97

Hello I have a 2007 A3 S line with the 1.4 TFSI engine. Earlier this year the timing chain slipped on my car causing £1800 worth of damage to the engine ,which included a new timing chain and chain tensioner, top end engine rebuild and a new cam shaft (not related to the timing chain issue but was found to be faulty in rebuild).The timing chain failing seems to be a common issue on VAG 1.4 turbo engines from the research i did when it failed ! Since the re build my engine seems to rev between 1500 and 2000 revs on cold start up. I mentioned this to the garage when it was newly rebuilt and they said its just the new parts need bedding in but it has done 6500 miles since the rebuild and it still does it, It starts OK when the engine is warm. Does anyone know what it could be ? Thanks