Hi again, folks! I'm back to haunt you all!

Just a quick question - looking at a cheap Terios automatic, listed with a fault of cutting out at tickover when cold, but ok once warm. Vendor states that it's in need of a service, though it's good point is that it's only got 66,000 on the clock and is in very nice condition - and advice or tips to the likely casue of the fault, please?