Much obliged to anyone who can give their thoughts on my problem.

I have a '98 A3 1.8T automatic with 56k on clock which is giving off a load of white smoke. It bellows out when accelerating and less when idle.

Originally I had an oil issue as the light was coming on. The car went to the local garage where they removed the sump, replaced crank main bearings and thrust washers, changed the pick up pipe, gave a new oil filter and flushed the oil. Not a cheap job as with labour, it came to £474.

Well, when I picked the car up, they said all was fine but there was a lot of smoke coming from the exhaust yet was nothing to do with anything they'd done and did not know the cause of it.

I've only driven it a few times since, one of which was on the motorway for about 20 miles to see if this would solve it but no go. It also gives a noticeable hiss when accelerating that gets louder the faster.

Today I took it to another garage and pretty quickly the problem was put down to the turbo seals. More noticeable was the fact there was little or no oil left.

My main question is whether this is the most likely cause and what needs to be replaced/worked on as well the nasty business - cost?

Thanking anyone in advance that can help this nasty headache!