Typical dealer / UK head office indolence and arrogance.

I posted a few weeks ago in the Technical forum about my son's BMW with the B48 petrol engine. In the US, these are subject to a free 'service call' to replace a plastic 'coolant vent tube' which connects between the cylinder head and the coolant expansion tank. This is failing in significant numbers, and there is a BMW US technical service bulletin describing it.

The tube is a hard plastic which becomes brittle from repeated engine heat-cycles and cracks (causing minor coolant weeps / loss) and eventually breaking completely (causing major unexpected coolant loss).

The vent tube on my son's 420i failed (broken off at the cylinder head), after 4.5 years and 47,000 miles, causing major coolant loss. Luckily he was only a few miles away and so was able to nurse it home without any overheating warnings.

However, despite the BMW US technical service bulletin, BMW UK claimed not to have heard of the issue, deny seeing any such failures on cars over here, and are not interested in offering any goodwill.