Topblag wrote:If BMW had wanted diesel engine's in their cabs, they'd have made it an option.
You could just as well say the same about M50B25s in E30s. There was plenty of overlap in the production dates.
There are two relatively easy possible ways to deal with the EWS. One is to buy what is commonly known a s a 'thief kit' - Matching ECU, EWS module and key chip - and fit it to your car. The other possibility, if the parts exist, is to use the ECU from an early M51, in the same way that an M50B25 with the silver label 413 ECU, which requires EWS, can be replaced by the earlier red label 413.
The 525tds used a variety of ECUs up to 1995, and a different one from 1996 on, so this could be worth investigating.
On a more general note, I find this an interesting project, and would like to see a full illustrated write up of it on here, which could well end up in its own sub forum in engine swaps!
I'm no great fan of diesel engines per se, but I am a fan of cheap motoring, and have the room and facilities here to grow and process oil bearing crops