M54 3 liter Swap --> BMW 525i Wagon

[ohdayum1234]

Hi everyone,

I recently picked up a 2001 525i Wagon for $700 on Craigslist with a blown engine. My dad and I decided to swap a 3 liter engine from the 530i instead of the 2.8 that comes with it, and we just picked up the motor and am beginning the process soon.

I researched and tried finding information about this swap (I know it sounds very major/easy compared to these LS swaps people do) and couldn't find much information on it. Has anyone done this swap before and can offer tips or point me to another thread that I might've missed? I plan on keeping this car after college so I wanted a decent increase in power while maintaining a factory-like driving experience. What components can I use from the 2.8 on the 3.0? So far, I have the throttle body noted that I will have to buy one specifically for the 3 liter.

This is my first time doing something major to a car besides your basic maintenance stuff (thank god my dad is a mechanic so it helps a lot) and am new to the community as well! Thanks for the help.

[328 Power 04]

The 525i came with a 2.5.

You will need the whole intake tract from the 530. Filter box to engine. This includes the larger MAF, throttle body, and intake manifold.

It's almost plug and play after that, just needs a simple flash update on the ecu to run the 3.0 engine and components correctly. Answers to questions that are usually following that previous statement:
- No, the ecu will not simply adjust to run the 3.0.
- It will "run" but suboptimally, lower power and less efficiently.
- To do the job right, a flash is necessary, yes.


This is an easy swap.

[ohdayum1234]

Sweet shouldn’t be too bad then. Thanks for the help! Will be installing a flywheel conversion kit from esc tuning since we already have everything pulled out. 👍🏽

[DakodaE39]

The 525i came with a 2.5.

You will need the whole intake tract from the 530. Filter box to engine. This includes the larger MAF, throttle body, and intake manifold.

It's almost plug and play after that, just needs a simple flash update on the ecu to run the 3.0 engine and components correctly. Answers to questions that are usually following that previous statement:
- No, the ecu will not simply adjust to run the 3.0.
- It will "run" but suboptimally, lower power and less efficiently.
- To do the job right, a flash is necessary, yes.


This is an easy swap.

I am about to do this in my 2003 525i, but i have an automatic transmission. I hear the torque converters are different? Cant i just take the flexplate off my 2.5 and put it on the 3.0 to get the torque converter to bolt up?
Also how do i flash my dme to run the 3.0L engine properly? I work for a bmw dealer, but i dont believe i can re program my dme to 3.0 with factory software, i could be wrong, i dont know.

[ohdayum1234]

I am about to do this in my 2003 525i, but i have an automatic transmission. I hear the torque converters are different? Cant i just take the flexplate off my 2.5 and put it on the 3.0 to get the torque converter to bolt up?
Also how do i flash my dme to run the 3.0L engine properly? I work for a bmw dealer, but i dont believe i can re program my dme to 3.0 with factory software, i could be wrong, i dont know.

How's it going man. I am not knowledgable about the torque converters being different, however I think you can get a flash or get it properly tuned by your local shop. I was looking into software for this but cheapest route might just be to get a tune from someone local... hope this helps. I'm a newbie to all of this so still lots to learn! From what I read online, most people stay away from the dealers and get it flashed/tuned else where.

- - - Updated - - -

UPDATE: New engine has successfully being attached and mounted! All that's left is to attach the wires, hoses, etc. FIRST START COMING SOON! Super stoked.

[328 Power 04]

I use the dealer/factory software and hardware. Most of the software (INPA, WinKFP, etc) is floating around to where you can do it easily on your own at home.

No clue about the flexplate and tq converter.

[DakodaE39]

I use the dealer/factory software and hardware. Most of the software (INPA, WinKFP, etc) is floating around to where you can do it easily on your own at home.

No clue about the flexplate and tq converter.

The torque converters are different, they have two different part numbers for the 2.5l and 3.0l. I will be buying an upgraded torque converter from Revmax most likely. The 3.0L TC is crap and will break internally sending debris throughout the whole transmission and therefor ruining the whole trans, which is highly expensive. Ill get the upgraded aftermarket TC and not worry about it anymore

Also I don't believe I can use factory software to re program my DME for the 3.0L engine. From what I have been reading I will have to use inpa and re code the hardware numbers for the 3.0L engine to work optimally, which wont be an issue as there seems to be some guides out there on how to do it. We will figure out when that day comes!

[Renzo520]

Revmax converters are excellent. Good choice.