NZ00Z3 187 Report post Posted December 12, 2016 (edited) Hi Looking at engine replacement options for a 2000 E46 that has a M52TUB25 from the factory. Don't want to get into LVV certification over Xmas so sticking to the 2.5L options. Been researching if a M54B25 will be a direct replacement if I use the existing headers and manifold. Yes I'll drop a HP or 2 off the M54 spec's, but if the engine fits, it will do nicely for a daily drive. Its looking very promising, but I can't confirm is the existing headers will bolt onto the M54 head. Has anyone tried this engine swap or can confirm the header question? Cheers Muzz Edited December 12, 2016 by NZ00Z3 Quote Share this post Link to post Share on other sites
allan 295 Report post Posted December 12, 2016 Can confirm if they will bolt up but have a look in the parts catalogue might have trouble with cats etc on the later models.Although it does show they were used on a m54 330ci and i http://bmwfans.info/parts-catalog/11621706538/ Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted December 12, 2016 yes all can be swapped around m52b25tu with the m54 bits on will be the same power etc as the m54b25 can supply either 2.5l or 2.8l options if needed Quote Share this post Link to post Share on other sites
NZ00Z3 187 Report post Posted December 12, 2016 Thanks everyone, M54B25 has been purchased Quote Share this post Link to post Share on other sites
qube 3570 Report post Posted December 12, 2016 its a great engine Quote Share this post Link to post Share on other sites
Olaf 3320 Report post Posted December 17, 2016 what about the ECU, Murray? Quote Share this post Link to post Share on other sites
NZ00Z3 187 Report post Posted December 17, 2016 2 hours ago, Olaf said: what about the ECU, Murray? Thank you for your comment. The ECU should all be good. The M52TUB25 engine is the M54B25 beta. Both are dual VANOS, 2.5 L and use all the same sensors, injectors, MAF and thermostat. I'm taking the M52TUB25 out and putting the M54B25 in with the M52TUB25 manifold and header. The ECU should not see any difference. It will adjust the fuel trims as it learns the new engine in hot/closed loop mode. The fuel trim tables for cold/open loop mode will still be for a 2.5L engine, so should not notice any differences. - Engine is on its way south from Auckland. - Two boxes of "all those other parts you should replace when the engine is out" are in the air from around the world - Will be making good use of any rainy days over the Xmas break with my head under the bonnet. - Have suggested to the family that a 4 day tin of good luck would make a great Xmas present for me. Quote Share this post Link to post Share on other sites
Olaf 3320 Report post Posted December 17, 2016 how cool is that? you're laughing, really. Do post your progress pics, you're bound to pick up encouragement here, particularly if your mojo is flagging and you're being tempted away from the garage by another ham sandwich! Quote Share this post Link to post Share on other sites