[Processing61]

This is more for the future but something I am considering.

I used to have an E90 330D, stage one + or stage two (can't remember now). With EGR and DPF delete running just over 300bhp and about 450 lb/ft of torque.

I've now got an E91 325D auto (200bhp) and from what I've read this is the same engine but slightly smaller injectors and turbo. At some point in the future, I would like to tune this as the DPF light intermittently comes on and is doing that more so recently. Its done 200k and isn't really worth buying a new dpf. I put wynns DPF cleaner directly into the DPF and that does usually clear it for a little while but it is coming back sooner now. So i may get rid of this (don't want to start a debate on whether to DPF or not to DPF lol) and at the same time have it remapped seeing as the DPF and or EGR will have to be mapped out anyway. Stage one with just DPF and EGR delete takes it to about 260bhp and 383 lb/ft of torque. Being greedy, stage two takes it very close to my OG figure on my last 330d, around 300bhp. So I was looking at taking it to those figures. But I would need different injectors for that. From what I understand the 325D M57 turbo is capable of 320bhp tops so I may be ok with the stock turbo.

I understand the M57 330D injectors won't work as the fuel rail layout is different so from what I've read the options are 218bhp X5, 201bhp E46 330D, M47 320d or E60 335D injectors. Or my current injectors could be retipped/different nozzles used. I then understand the car would need coding for the new injectors.

I was wondering what may be the best route? Most reliable and (dare I say) cost-effective?

Thanks.

[Silver Streek]

Which 325d engine do you have? Is it the M57 or the N57?

It's the M57 that's different to the 330d version. The injectors are smaller, but the turbo and intercooler are the same as the 330d. The inlet manifold is different in that the manual gearbox version does not have swirl flaps fitted (not sure about the auto version).
Most tuners that I have read info from use 535d injectors as these seem to be most suitable for tuning decent power.

The N57 is the same as 330d physically but is detuned via software.

Sounds like there is a fault which is stopping your DPF from regenerating, probably something simple. But if you are getting rid of it I guess that not an issue.

[Processing61]

Originally Posted by Silver Streek

Which 325d engine do you have? Is it the M57 or the N57?

It's the M57 that's different to the 330d version. The injectors are smaller, but the turbo and intercooler are the same as the 330d. The inlet manifold is different in that the manual gearbox version does not have swirl flaps fitted (not sure about the auto version).
Most tuners that I have read info from use 535d injectors as these seem to be most suitable for tuning decent power.

The N57 is the same as 330d physically but is detuned via software.

Sounds like there is a fault which is stopping your DPF from regenerating, probably something simple. But if you are getting rid of it I guess that not an issue.

Yes it’s the M57, M57N2 to be precise.

Oh right, that’s good to know. I thought the turbo was slightly different too.

On my particular one (M57N2 325d auto) it doesn’t have swirl flaps. This didn’t have it from factory.

The fault is back pressure too high and soot content too high, won’t burn off when regenerating on a drive or forced regen. The DPF cleaner helps lower pressure and soot a lot but not enough and it clears it for a while then comes back again. Interestingly, it never has gone into limp when the DPF light comes on. Apparently this is the og DPF so it has seen some miles.

[Silver Streek]

Maybe your DPF has reached the point where it needs a clean. There are a fair few companies out there that have a proper rig for flushing them out. And I don't mean a hight pressure hose though the box over the drain out back lol. Much cheaper than a new DPF.

The good tuners can tune 3ltr diesels into (325 included) the 300 BHP range with a DPF fitted so you can leave it on and still gain good power. Your choice but I know what I would do.
BWchiptune seem to get pretty good reviews on here for mapping cars they dune with the DPF in place and get good numbers by all accounts.

[Silver Streek]

I'm interested with what you do as I also have a 325d, mines one of the last M57 versions as it and early LCI car just before they introduced the N57, mines a December 2009 build car. I have a superchips map running, but would be interested in the 535d injectors then rolling road setup to see what the power gains are. I've heard the 300 range is possible.

[Andystobbs]

Is your turbo 'making' oil and causing your DPF problems?

[Processing61]

Originally Posted by Silver Streek

Maybe your DPF has reached the point where it needs a clean. There are a fair few companies out there that have a proper rig for flushing them out. And I don't mean a hight pressure hose though the box over the drain out back lol. Much cheaper than a new DPF.

The good tuners can tune 3ltr diesels into (325 included) the 300 BHP range with a DPF fitted so you can leave it on and still gain good power. Your choice but I know what I would do.
BWchiptune seem to get pretty good reviews on here for mapping cars they dune with the DPF in place and get good numbers by all accounts.

I have heard mixed reviews of the professional DPF cleaning. Is there a particular way/system that is meant to be good?

I know what you mean, I have read of quite a few good tuners who won’t advise to remove the DPF. It certainly would save the increased diesel smell and potential issues with MOT’s.

[Processing61]

Originally Posted by Silver Streek

I'm interested with what you do as I also have a 325d, mines one of the last M57 versions as it and early LCI car just before they introduced the N57, mines a December 2009 build car. I have a superchips map running, but would be interested in the 535d injectors then rolling road setup to see what the power gains are. I've heard the 300 range is possible.

I will update here if/when I do anything. It won’t be soon though. Just getting some ideas together

[Processing61]

Originally Posted by Andystobbs

Is your turbo 'making' oil and causing your DPF problems?

Interesting. Sorry if it’s a rookie question, how would I check that, leaking oil from turbo seals that is somehow getting into DPF? Can that be a “common” problem?

[Andystobbs]

Take the dpf off and see if its soaked in oil.

[Processing61]

Originally Posted by Andystobbs

Take the dpf off and see if its soaked in oil.

I thought that may be the case, seems a bit of a pita to take it off. Willing to do it if I have to lol

[Andystobbs]

DPF's are ridiculously reliable when everything else works properly and the car gets a good run periodically.

[rasa bmw]

id fix the car first,ie why is the dpf getting blocked,if you know that then you can go forward,they dont just block because of short trips...could be thermostats egr/main, not letting coolant get to temp etc

[Processing61]

Originally Posted by Andystobbs

DPF's are ridiculously reliable when everything else works properly and the car gets a good run periodically.

This is the OG one and it’s done 200k so I can believe that!

[Processing61]

Originally Posted by rasa bmw

id fix the car first,ie why is the dpf getting blocked,if you know that then you can go forward,they dont just block because of short trips...could be thermostats egr/main, not letting coolant get to temp etc

Yeah maybe I should pay more attention to it. The main thermostat has just been changed, egr hasn’t but car is getting up to temp ok and thermostats open fine. I know the egr is still in place/hasn’t been mapped out and physically blocked so I could look there too, seeing the 200k mileage. May e it’s very blocked

[rasa bmw]

Originally Posted by Processing61

Yeah maybe I should pay more attention to it. The main thermostat has just been changed, egr hasn’t but car is getting up to temp ok and thermostats open fine. I know the egr is still in place/hasn’t been mapped out and physically blocked so I could look there too, seeing the 200k mileage. May e it’s very blocked

wat emps is it reaching ?and these stats get stuck open etc,so hard to detect unless you are getting to fulloperating temp,ie over 88-94 degrees,,at least 75 degrees and over a quarter tank of fuel is needed to perform a regen

[Processing61]

Originally Posted by rasa bmw

wat emps is it reaching ?and these stats get stuck open etc,so hard to detect unless you are getting to fulloperating temp,ie over 88-94 degrees,,at least 75 degrees and over a quarter tank of fuel is needed to perform a regen

I’ll check and get back to you thanks