N53 330i NOXEM review

[SoupAnxiety]

Hi all,

I decided to get a NOx emulator from http://bimmerprofs.com/ to replace the failed NOx sensor on my N53 330i. My 330i is on 172k with an aged NOx cat but I wanted the more economical lean burn modes back. This sensor works as advertised, the car is now running in (comparative) eco mode at low to mid load.

Real world MPG is up from ~26 MPG (300 miles, mix of 5-10 mile journeys and 50+ mile motorway jaunts in a typical week) to an easy 35 MPG with bursts of full throttle and motorway cruising around 80 MPH. Tank range on super unleaded is up from 380 miles to 520 miles (!!!) and on a journey back from Wales tonight after taking it really easy 43 MPG over 80ish miles each way (160 miles round trip) was achieved.

The sensor cost £300, was delivered from Latvia in four days and will pay for itself in saved fuel. It's recommended and considering the mileage on my engine and associated components I'm delighted.

[SoupAnxiety]

Badgerboy said:

How did you find the install process? Relatively straight forward?

I asked my independent mechanic to install it whilst it was in for a service. He had no problems encoding the NOx sensor and catalyst replacement, reseting adaptations and clearing codes using the universal third party programmer. Only painful bit was getting the undertray off after nine years and 172k miles, "persusaion" was needed.

The site includes all sorts of information about using INPA to encode yourself. It might give better results doing this but all I've done is had it installed as above and driven for 200 miles to allow it to bed in.

[SoupAnxiety]

Long term update after a few thousand miles.

Round town / urban only is 32 MPG.
Real world mixed driving is around 35 MPG.
100+ miles of motorway use is an easy 40 MPG.

This was my return trip of 240+ miles, including spending one hour in stop start traffic on the M5 and at least half an hour in the same joy on the M42. 42 MPG! Car had four people in and loads of luggage too. I reckon 45ish MPG would be the best effort.

Interestingly, 68 MPH / 110 KPH @ 2,350 RPM seems to be the sweet spot in mine for economy, 60 MPH / 70 MPH were slightly worse and 75+ MPH goes off a cliff (18" wheels, super unleaded).

I can wholeheartedly recommend NOXEM. Installation and adaptation process works as described, and my car is fault code free.

[SoupAnxiety]

bmwmike said:

Fair play!! Good to see. I'll definitely get one when my OE one plays up.

The n53 gets knocked on here quite a bit but they are a good engine when running right.

How is your oil consumption at that mileage?

Over the years I've replaced my injectors with the later index 11 variant, replaced coils and now the NOx sensor. As you said, when running right the N53 really is a great engine. Rewards you for driving carefully and for driving quick! They suit a manual gearbox and are very underrated engines. The NOx sensor has been on my fix list for ages, but it looks like injectors / coils / NOx together make for a happy (and hopefully long term reliable) car. On reflection, the NOx sensor is worth doing very early on as it will pay for itself.

Oil consumption is around 1 litre every 3,000 miles, it can vary by ~500 miles either side depending on the sort of driving that I do. It was down to 1 litre every 800 miles when the CCV membrane failed, replaced that myself without replacing the valve cover. My DIY is at https://www.pistonheads.com/gassing/topic.asp?t=16.... Car wears its mileage well, the giveaway is the number of stone chips on the bonnet, but it's rattle and knock free and belies its age (2009/59) and mileage.

I plan to keep my N53 330i for as long as possible. The car has been pampered by me, it's sat on Bilstein struts and Eibach springs, new discs, everything replaced underneath and plenty of preventative maintenance. It's a curiosity now, at the risk of tempting fate, how long will it go on for! Hopefully it'll last until I can afford a tidy E39 M5.

Edited by SoupAnxiety on Monday 6th August 18:50

Edited by SoupAnxiety on Monday 6th August 18:50

[SoupAnxiety]

PSDM3 said:

I didn't see a huge difference in changing my NOx sensor. - Maybe +1 or 2 mpg.
I still get around 15mpg around town, and 30mpg on the motorway. Never ever seen 40mpg avg on my 330i N53 2010 (even if I reset it on the motorway). Maybe if the whole motorway stretch is down hill I might.

I know my injectors need sorting... did they make a big difference to your MPG after they were sorted?

The injectors didn't really help. Are you using NOXEM or a BMW original replacement sensor? Fault codes? It might be worth following the advice at http://bimmerprofs.com/, your MPG doesn't sound right at all.

[SoupAnxiety]

PSDM3 said:

BMW original - £430.

If the injectors didn't make a big difference, then I am out of ideas. No fault codes come up in relation to the engine, just one in regards to iDrive. Fuel or air filter? Doubt it. I'll have a look at the bimmerprofs site

Edited by PSDM3 on Wednesday 8th August 13:37

Depending on mileage your NOx cat may be the issue. The original sensor may report that the cat has aged. This is what NOXEM overcomes, it restores full functionality by emulating NOx cat OK status.

[SoupAnxiety]

Olson said:

Hi. Thanks for the write up - the info you have posted is great feedback about Bimmerprofs' NOX Emulator. I have a dead BMW NOx sensor for the second time + also the dreaded "NOx Catalyser Ageing" fault code, so am almost certainly going the route of fitting a NOXEM.
Can I ask - Is all still going well with your NOXEM, i.e. is it proving reliable and still enabling stratified charge mode etc?
Thanks

All going well - ~7 months in and it's working perfectly. Zero fault codes (as in no fault codes at all, NOx or otherwise), all burn modes working and vastly improved MPG round town and under cruising loads. Would recommend it to anybody, as I've said my only regret is not doing it sooner and saving £££ on fuel. At the risk of making a Brexit reference, there are no downsides to NOXEM, only upsides.

[SoupAnxiety]

bmwmike said:

So the opposite to Brexit then.

Good to hear it's still working well for you. Presumably those ebay injectors are still going strong too?

Agree completely about Brexit. NOXEM promises no downsides and delivers no downsides, Brexit promised no downsides and instead delivers *only* downsides.

eBay injectors have been installed since February 2017, for 20k miles. Still going strong. They've been running with NOXEM for around 4k and haven't lunched themselves yet. You can hear them switching modes after installing NOXEM and it's quite futuristic (or as futuristic as a 10 year old engine design gets).

[SoupAnxiety]

bmwmike said:

Phew, agree on the B word, after I'd written my post I realised it could have been taken either way!! Right nuff said about that I think.

Switching modes - interesting - really? The only thing I don't like about my n53 f10 is the idle noise some times sounds like a brake disc lip rubbing, metallic a little like a scrape sound. And at idle, after idling for a while.. something clicks and it stops. Is that it?

Idling sounds diesel like - mine always did this, even with a knackered NOx sensor / no fancy burn modes. Think this is a symptom of high pressure injection.

The burn modes you can hear at low revs (<1k), then there's a step change to <4k and beyond is normal burn. Tough to describe but imagine mechanical ticking and venting. It's most noticable if you're in a 30 - 40 MPH zone and are pootling along with the radio off. Not unpleasant or harsh, just... different. Only noticed after NOXEM being installed.

[SoupAnxiety]

KH47Ed said:

hi i'm looking at getting NOXEM 130 for my 320i (n43) i've spoken to the guys over at bimmerprofs and they're really helpful, even had a bit of brext banter haha rather than spending £400 on the BMW original, because i know mine defo has the 30ea code messing up my fuel efficiency, i've had enough of 20mpg, when i first bought the car it was averaging around 40mpg and then one day i got my hands on inpa erased all adaptations and reset codes and its never been the same since.

My question is how hard is the coding bit or is it as simple as deleting the adaptations and fault codes? I trust my mechanic to delete adaptations and reset fault codes but beyond that i'm not really sure if he'd do any coding if its required. My former mechanic before this one was a pure heathen, he use to tell me dont worry about the computer and techy parts just put the physical part in and you're good to go, several hundreds of pounds later i know thats not the case especially with german motors, maybe with 'dumber' cars but defo not this one. I once spent 8hrs getting to a faulty bank 1 o2 sensor on this motor, to put things in perspective in another motor (peugeot) i had this done in 30mins.

The only other coding beyond resetting fault codes is that the ECU needs to be told the NOx cat has been replaced. Shouldn't be too difficult if your mechanic can do the rest.

[SoupAnxiety]

KH47Ed said:

Would erasing adaptations do the same job as telling the ECU NOx sensor has been replaced?

No - it's a separate task, fault code / adaptation reset isn't the same. After the NOx replacement and NOx cat replacement coding I have zero fault codes on the DME, do a fault code scan and see if you have anything relating to NOx (aged cat etc).

[SoupAnxiety]

markirl said:

Thanks for this thread, really interesting. I have a manual n53 530i and have had a 30e9 warning on the car for a few years now. My economy is OK, generally averages 30mpg, but from reading your thread it would appear that 30e9 means I'm losing lean burn mode? Do you think I should buy NOXEM?

I would if I were you - my only regret is not doing it sooner!

[SoupAnxiety]

Gary Deasy said:

Hi Guys
I just bought NOXEM 130 and am getting a mechanic to fit it. This is going to be a stupid question possibly but which lambda probe does it replace?
There are 4 i think , 2 sensors in the engine bay and 2 along the exhaust. I know it is one of the sensors in the exhaust that NOXEM replaces but is the one that is furthest from the engine or the one before that? I am assuming the one furthest from the engine , but I just want to be doubly sure

Cheers
Gary

You're right - furthest from the engine.