There may be one or two fluke 20i engines that run well forever, but those are very, very rare. In general, the 20d engines are more likely to outlast the petrol motors and also less likely to give issues.
As suggested above, you can search the forum for issues on the petrol engine.
So I didnt think I would have to do a write up about the petrol F – series engines. My usual comments over the years to clients with the petrol E-series generation was “service every 10000KM or once a year as this car is prone to sludge and engine issues” I said this like a …
The most common BMW N20 engine problems and reliability issues. N20 timing chain failure, valve cover and gasket leak, oil filter housing gasket leak, etc.