e39 Engine Swap

[MikeyMike]

My current daily is an S registered 520i. It cost me bugger all and my original intention was to run it till it died and weigh it in....however, the bloody thing has gone and gotten under my skin. Yes its deathly slow, and with its puny 16 inch alloys and SE spec its hardly a fire breathing sex machine. It is though, almost perfect for my weekly commute down the M4, has a mint interior and the best steering of any car I've ever driven.

Trouble is, the engine is bearing down on 150k and a sniff test has revealed exhaust gasses in the coolant. I don't have the funds to buy a suitable replacement so I've been thinking of a DIY engine swap. Ideally I'd like to stick a bigger/more powerful engine in there rather than go for another 520i lump but what are the realistic options?

Thanks in advance.

[BritishRacinGrin]

You have the M52B20 so as far as I know the M52B28 would be a bolt-in replacement provided you get the ECU and probably some other ancillaries to match. However E39s are cheap and plentiful so my suggestion would be to just buy a 528i and pillage your 520i for parts.

[Dannbodge]

I would agree with the above comment.

Old E39s are a easy to find and even for a decent one it will be cheap. If you find a mechanically sound one that is tatty, use your parts to make it nicer.