[Jros]

Recently had the dreaded oil consumption problem the N52B25 is known for, and it occured in a matter of days that the oil consumption skyrocketed from none in 10k KM to 1 liter in around 50 KM...

This was a good clean B25 cared for, extremely clean, and with less than 100k miles on it.

Awful...

So, i bit the bullet, found a reasonable priced complete N52B30 with 99k KM from an automatic 2005 E90 330i MSV70 with right hand drive, and decided to shove it in my E92 euro manual 325i MSV80 car, left hand drive

I am writing this just for the guys wondering if an EU 325 / AUS 323 can be converted to the B30, the answer is: very very easily!

I kept the wiring loom and ecu from my car, just switched valve covers, MAFs and throttle bodies (MSV70 has differnt plug form factor and possibly pinout) and then plugged the oil return hole for the CCV system, now unneeded.

I swapped my MILVS from the B25 to the B30 too obviously

the engine swap itself is seamless, every thing from the gearbox, flywheel and clutch (kept mine, i had the valeo single mass kit) to the wiring, mounting positions et all is identical.

Keep an eye out for the different oil pan if you buy an auto car engine though, it is a bit differnt shaped and you will have some difficulties with letting it past the subframe if you push the engine in from above and don't lower the subframe like i did. It gets trough but it will give you many opportunities to use your collection of swearwords and profanities.

As long as software: the engine starts and run even on the B25 rom, at least for 325is.

It will run and you will feel a bit of torque gain, but you will have some low rpm high load hiccups, so i higly suggest to contact the awesome guys at 22RPD for custom software, like i did

I guess if you can find a MSV80 330/130I rom and have some skill you could fix it yourself, but i think that for the price asked for, having a tune above that is good.

Good luck to anyone attempting

[Jros]

[nabeel.m07]

Originally Posted by Jros

Recently had the dreaded oil consumption problem the N52B25 is known for, and it occured in a matter of days that the oil consumption skyrocketed from none in 10k KM to 1 liter in around 50 KM...

This was a good clean B25 cared for, extremely clean, and with less than 100k miles on it.

Awful...

So, i bit the bullet, found a reasonable priced complete N52B30 with 99k KM from an automatic 2005 E90 330i MSV70 with right hand drive, and decided to shove it in my E92 euro manual 325i MSV80 car, left hand drive

I am writing this just for the guys wondering if an EU 325 / AUS 323 can be converted to the B30, the answer is: very very easily!

I kept the wiring loom and ecu from my car, just switched valve covers, MAFs and throttle bodies (MSV70 has differnt plug form factor and possibly pinout) and then plugged the oil return hole for the CCV system, now unneeded.

I swapped my MILVS from the B25 to the B30 too obviously

the engine swap itself is seamless, every thing from the gearbox, flywheel and clutch (kept mine, i had the valeo single mass kit) to the wiring, mounting positions et all is identical.

Keep an eye out for the different oil pan if you buy an auto car engine though, it is a bit differnt shaped and you will have some difficulties with letting it past the subframe if you push the engine in from above and don't lower the subframe like i did. It gets trough but it will give you many opportunities to use your collection of swearwords and profanities.

As long as software: the engine starts and run even on the B25 rom, at least for 325is.

It will run and you will feel a bit of torque gain, but you will have some low rpm high load hiccups, so i higly suggest to contact the awesome guys at 22RPD for custom software, like i did

I guess if you can find a MSV80 330/130I rom and have some skill you could fix it yourself, but i think that for the price asked for, having a tune above that is good.

Good luck to anyone attempting

Hi Jros, firstly congratulations on the swap! Im writing because im interested in doing the swap myself on a 325i e92 euro edition with the N52B25AF engine. I plan on swapping in the N52B30AE. I’ve looked extensively over every single different part between the e92 330i and e92 325i on real-oem, and it comes down to the engines, transmission (GS6-16BG vs GS6-37BG in the 330i), drive shafts, differentials, and wheel bearings, as well as the exhaust systems and exhaust manifolds. My plan would be to do a full conversion of allnof these parts (beside maybe the diff which i might consider keeping from the 325i for a lower ratio compared to the 330i’s) over a number of years, starting with the engine. My question’s to you are as follows :

1. Could I do this swap by only swapping the 3.0l engine directly in for the 2.5l and have all other existing hardware in my 325i be compatible i.e. exhaust manifolds, drive shafts, transmission

2. Have you encountered any issues since you’ve done the swap

3. Are you running the stock e92 325i transmission which, if you have a manual I believe is the same as mine (GS6-17BG getrag transmission), and how is it holding up if so

I’d really appreciate any feedback on the matter, kind regards - Nabeel

[Jros]

I kept almost everything original when i did the swap, essentially all that is connected to engine harness remained the same, even ECU software i kept the same for a while with no problems apart for lower power than a B30 can have, and somewhat jerky throttle at low load low rpms, probably normal cause the ecu had models for a lower capacity engine.

my B30 was of older specs, had magnesium cover for external CCV, if you will use the same vintage engine, i suggest you get rid of the mag cover and use the N52K plastic one- be wary that the disa intake manifold for older N52 has a single nipple for the CCV output and plastic valve cover has different diameter nipple too, so some fabrication is needed, i just cut a new CCV hose, used the quick connects and regular hose to fabricate one for the application.

answering to your specific points:

1. Could I do this swap by only swapping the 3.0l engine directly in for the 2.5l and have all other existing hardware in my 325i be compatible i.e. exhaust manifolds, drive shafts, transmission ---> YES, i kept everything original apart the engine itself with zero problems

2. Have you encountered any issues since you’ve done the swap ---> NO, nothing swap-related at all ever happened- obviously i suggest you find a way to reflash the ecu with proper sw for a 3.0, i was helped by 22RPD, car is tuned now

3. Are you running the stock e92 325i transmission which, if you have a manual I believe is the same as mine (GS6-17BG getrag transmission), and how is it holding up if so --> YES, it is holding up just fine- i just upgraded the clutch to the 330I spec one, if i remember correctly it is like 10 or 20mm larger in disc diamater

good luck with the swap!