Here is the full analysis and what to beware of.

The turbo is positioned at the top rear of the V6, and there is a oil seal which thanks to a brilliant design, hangs perfectly over a crucial unit known as the inlet port cutout motor, buried deep in the V. The MB garage knows that this can lead to problems should it leak, and they check it during the service. However, during those 8 months since the last service, a leak started from the turbo oil seal. This loss is undetectable by doing a dipstick check and I vaguely remember picking up a whiff of burning oil on just a couple of occasions, but so minor I couldn't even tell if it was my car.

On this fatefull Saturday the said inlet port cutout motor, now full of oil, catastrophically failed at motorway speed, did its job and shut down the engine. I can't associate the failure with the starter motor being burnt out, hence the inability to crank, but it had to replaced. To add insult to injury, to get to the oil filled cutout motor, the turbo had to be removed and of course one of the bolts was completely siezed and had to be carefully drilled out. The total bill for a failed £4 oil seal came to £1300, so should you have a V6 MB and detect just the tiniest whiff of burnt oil, don't ignore it.

Fred