Originally Posted by mubeenkhan

While trawling through the e60 forums one of the things that I have noticed is that 550i owners tend to complain about a lot fewer issues as compared to the 545i owners. When I say issues, for the sake of this discussion we can limit the conversation to repairs related to the engine. Just wanted to see if there is any substance to say that the 4.8L v8 on the 550i is better in terms of reliability than the 4.4L v8 on the 545i. I can begin with a laundry list of issues that typically characterize the 545i

1. Valve cover gaskets
2. Upper timing cover gaskets
3. Alternator bracket gasket
4. Transmission mechatronics sleeve
5. Vacuum pump and oil switch

I thought it would be interesting to to see if 550i owners had related observations/experiences to share.