[Dmitry235]

Hello everyone!
I have a 2013 BMW 328I. Originally was installed the N26 engine which was apart when I got the car. I purchased another N26 engine from jankyard and swap it. I have to install a new valve cover for N26 and used HPFP from the N26 engine.
Long story short, junkyard sold me N20 engine and now I'm getting a mixture too lean code. Check engine light on. The car runs great, sometimes a bit rough cold start. If I cleared code and returns very fast which is kinda weird for lean code.

I was looking for info on what I need to swap to get the job done.

- injectors coded
- engine was smoked, no leaks.
- since I installed a new valve cover from N26 it has a small hose going from PCV valve. Should I leave it open or just clog it?

UPD: changed fuel injectors for EU6 SULEV, no change.
UPD: donor engine was N20B20A

[sqwinny]

Everything for the most part crosses over. The biggest issue is if you purchased a high or low compression engine as a replacement. If you put a different one in, there's your DME issue for a base tune. Fuel injectors are different (can be coded to upgrade downgrade as you have done, fuel line is updated from what I recall and depending on the year timing chain was updated for the 2012-2018 cars.

[Dmitry235]

Originally Posted by sqwinny

high or low compression engine

I read N20 and N26 are identical just have different parts on and different emission system. How they can have different compression level?
What can cause the lean code?

[sspade]

Originally Posted by Dmitry235

I read N20 and N26 are identical just have different parts on and different emission system. How they can have different compression level?
What can cause the lean code?

The N20 specifically... has two different compression variants. In the USA, 20i are the high compression units and 28i are the lower compression. This is achieved primarily through different piston design and factory tuning.

[ScottSmith]

Unfortunately, whatever system the dismantlers use says the two engines are equivalent. Copart etc will happily list a 320i engine as a substitute for a 328i engine. The N20B20A is equivalent to an N26, while the N20B20B is the 320i / high compression version. Note not all 20i engines are N20B20B, for example I *think* the X3 20i or X1 20i engine is actually a N20B20A.

I had a dismantler ship me a 320i engine instead of a 528i engine; I had to return it and explain why it wasn't the same.

You can tell them apart two ways. On the front, just to the right of the water inlet to the block is etched the engine serial number. Starts with either A###### or B######. Below that it should be etched wither N20B20A, N20B20B, or N26B20A.

Alternatively, and less reliably, there's a sticker where the transmission mounts on the turbo side. It supposedly lists chassis code (F##) and production code (something like 1F53 for USA F22 N20 vs 1F93 for USA F22 N26), though I've gotten engines with production codes from Europe before.

[Dmitry235]

Wow, didn't know that.
Donor engine was from 2017 BMW X3 28i AWD. My car is 2013 BMW 328i
We swapped oil pan and all the rest fit perfectly. Runs good but the only one problem is lean code 118001 and sometimes 118401.
Yesterday reset all adaptation after new injectors installed and check engine come back in next 3-5 miles.

UPD: donor engine was N20B20A

[Dmitry235]

Any idea about lean?

[socalr53]

just an observation. Since the code is fuel related and I see you swapped HPFP from the old engine. you think the HPFP may have been bad to begin with ?

A lean mixture is a great way to kill the engine. especially if you go WOT

[socalr53]

this line from your original post (below) also raises a red flag. Dunno where this hose supposed to go, but a leaking valve cover can trigger a lean code too

"- since I installed a new valve cover from N26 it has a small hose going from PCV valve. Should I leave it open or just clog it?"

[ScottSmith]

Read through this thread. I might have given bad advice (I said to leave it disconnected!) but someone else mentioned CEL with lean code.

https://f30.bimmerpost.com/forums/sh....php?t=1749864

[0909905000]

Originally Posted by Dmitry235

Hello everyone!
I have a 2013 BMW 328I. Originally was installed the N26 engine which was apart when I got the car. I purchased another N26 engine from jankyard and swap it. I have to install a new valve cover for N26 and used HPFP from the N26 engine.
Long story short, junkyard sold me N20 engine and now I'm getting a mixture too lean code. Check engine light on. The car runs great, sometimes a bit rough cold start. If I cleared code and returns very fast which is kinda weird for lean code.

I was looking for info on what I need to swap to get the job done.

- injectors coded
- engine was smoked, no leaks.
- since I installed a new valve cover from N26 it has a small hose going from PCV valve. Should I leave it open or just clog it?

UPD: changed fuel injectors for EU6 SULEV, no change.
UPD: donor engine was N20B20A

I'm in the same situation as you and need advice

The N20B20A engine was purchased to replace the N20B20B and had problems with vibration and unstable intermittent explosions.

I'm getting ready to recheck my DME

Can you give me some advice?

[sqwinny]

If you see N20B20A= 10:1 compression ratio.
If you see N20B20B= 11:1 compression ratio.

Physical dimensions everything is the same, the compression ratio is different and your fuel injectors which came with the motor (if it did) may be different as there was a transition period for eu5 -> eu6 specified fuel injectors.

Aka it's not a straight swap as when you change compression ratio, you need to retune the car/swap over a compatible DME which is also high compression as well. there are ways around this which require a tune. Any BMW indy shop would understand the changes + what would need to be done to make this work.