Help needed urgently - swapped engine possibly at risk

[Breeze1]

Hello everyone,


I'll try to make the long story as short as possible lol. I own a 2001 manual e46 323i and I have recently started experiencing misfiring only when the engine is warm and only at very low revs (below 1500), with a slight burning smell coming up when I stopped in traffic.

After narrowing down with my mechanic the possible cause to a clogged catalytic converter (checked the spark plugs, ignition coils, hoses. They all seemed to be good. We did a test drive with a diagnosis tool plugged into the OBDII port and it DID come up with a DME fault code, but according to him it could be pointing at some other "undeclared" issue related to the misfiring) we had planned that I would come back next weekend to have it replaced or temporarily gutted because I did not want to buy a brand new one.

After leaving his shop I thought I would put some injectors cleaner in the car and drive about 10-15 miles at high revs just in case the injectors were clogged. A rough saturday after a rough week made me make not one but two mistakes lol :
- I confused the unknown brand the gas station sold me (some "euro sTop" sh*t) with STP
- I only put about 3 gallons of gasoline with it instead of a full tank, thinking it would be more efficient.


After driving 15 miles on highway with no problem at all I entered the city and at the first stoplight the car made a noise that reminded me of a firework, then the car stalled. When I opened the hood the burning smell was much nastier than before and when I tried to start it back up after a while it barely started and made all kind of metal noises. Anyway after towing to the garage he told me that the engine had blown up and it is now being replaced (we concluded that the combination of several causes led to the failure of the engine: clogged CAT, bad injector cleaner with too little gas and what we would discover after pulling the engine up: it had already been opened, which I suspected because when I bought the car it had a brand new OEM radiator on, while on the other hand it had been generally poorly serviced...

Basically I now have 2 very worrying questions and one that is not lol:
- Could the faulty DME (if it really is) have possibly caused the engine to literally break?
- If the previous is possible (which I don't think it is), could the DME cause the new engine to break??
- The new engine is a 2.8: I know that my DME can basically adapt and manage it, but do I absolutely need to have it flashed if I want the 2.8 to behave normally/like a 2.8? If I need to do it i will but for now I'm trying to avoid any additional expenses...

Thanks for reading and please shed a light on those questions lol

Edit: the mechanic told me that what seemed like a misifiring could in fact have been caused by a failing piston on its last breathe. I had also noticed like 2 weeks before the engine broke that after 10-15 miles of rather intense driving there was a little white smoke coming out of the exhaust...

[328 Power 04]

The dme is probably not at fault. And the 323 dme will not "basically adapt". It will run the 328 engine poorly.

[Breeze1]

The dme is probably not at fault. And the 323 dme will not "basically adapt". It will run the 328 engine poorly.

Thanks for your reply. I will have to flash it sooner or later yeah, but I was wondering how it would do in the meantime. By "poorly" do you mean that it wouldn't be better than a 323, or not significantly better, or will I still be able to notice a difference?

[Breeze1]

The M52TUB28 was taken from an auto 528I and my car is a manual 323i as stated above. Long story short I'll probably have to do the flash myself since the guy who could do it lives like 300 miles from where I live and I would rather save the money. Basically here is what I have at my disposal:
- OBDII bluetooth adapter and torque pro (useless for that)
- an OBDII interface cable
- a laptop
- my stock DME, which if I understand well is a MS42.

Guys I would GREATLY appreciate if someone could point me in the right direction as per how to do it myself, like step by step because I have never done it so far. I have found a lot of posts on the subject but they never fully meet my case or if they do they only talk about a part of the process, not all of it.

That would be VERY helpful for me, since it would be a huge disappointment for me to spend all that money and go through all that hassle and not even be able to enjoy a proper running M52TUB28
Thanks.

IMPORTANT EDIT: I'm carrying over the M54B30 intake manifold and the CAI I had on the M52TUB25 , which I had not done a remap for yet, and since the CATS probably contributed to shooting my previous engine I'm thinking about keeping them gutted until I find some high flow CATS. So IDEALLY I would like to directly dump the right program for that while I'm at it.

On a side note, with this setup and the proper remap what am I looking at, like 220/230ps at the crank?

[Breeze1]

Here is a pic of the patient

[Breeze1]

Wow like no reply at all although I'm sure many could help

[MauiM3Mania]

Wow like no reply at all although I'm sure many could help

Wow, like the many here that help do so on their free time. Being demanding isn't going to get you far.

[Breeze1]

Wow, like the many here that help do so on their free time. Being demanding isn't going to get you far.

I was just expressing my disappointment/frustration given the circumstances and the fact that despite the huge amount of knowledge gathered by this community nobody replied except 328 Power 04 with his comment about the DME.
I was just expecting that someone would take 1 minute or 2 to share a link with me or something, the same way you took 1 or 2 minutes from yours to "educate me"...

[328 Power 04]

This pack I loaded here has WinKFP (flashing of modules) with preloaded MS42 flashes.
Use realoem.com to determine the zb number you want. The eu2 flash versions delete catalyst and rear oxygen sensor delete, but also your check engine light always off. (Can be turned on again with custom tuning)

- - - Updated - - -

https://www.bimmerforums.com/forum/s...xperimentation

- - - Updated - - -

All you need is in the first post, read thoroughly.

[MauiM3Mania]

I was just expressing my disappointment/frustration given the circumstances and the fact that despite the huge amount of knowledge gathered by this community nobody replied except 328 Power 04 with his comment about the DME.
I was just expecting that someone would take 1 minute or 2 to share a link with me or something, the same way you took 1 or 2 minutes from yours to "educate me"...

Check the time zones. These guys sleep too.

[Breeze1]

Thanks man, appreciate your help! I'll read through it!

This pack I loaded here has WinKFP (flashing of modules) with preloaded MS42 flashes.
Use realoem.com to determine the zb number you want. The eu2 flash versions delete catalyst and rear oxygen sensor delete, but also your check engine light always off. (Can be turned on again with custom tuning)

- - - Updated - - -

https://www.bimmerforums.com/forum/s...xperimentation

- - - Updated - - -

All you need is in the first post, read thoroughly.

[ross1]

Wow, what a hot mess this one is.
Good luck, I'd start with a new mechanic.

[Breeze1]

The mechanic is very knowledgable when it comes to the analog/mecanical parts, but as far as programming goes he can't do it.
Thanks!

Wow, what a hot mess this one is.
Good luck, I'd start with a new mechanic.

[ross1]

The mechanic is very knowledgable when it comes to the analog/mecanical parts, but as far as programming goes he can't do it.
Thanks!

If you say so