NOx sensor is an easy job for a garage, and unless there’s a backorder they should be able to get hold of them within a 24hr turnaround from any BMW dealership.

It’s difficult to say whether it’s ok to drive - the sensors control fuel mixture so if the car otherwise runs fine with no symptoms then you might be ok. I’d make sure you disable auto stop/start to reduce wear on the chain, though! Could be worth buying a breakdown policy that covers you in Europe too?

Remember you have 6 months from the date of purchase to demand a refund or repair to the car under UK consumer rights law - if the seller doesn’t want to play nice with their warranty, your local Citizens Advice can help you force them to!

 

Thank you. As you can understand I'm a little nervous as for the week's window of opportunity so confirming an on average 24 hour turnaround does help. There are some other (hopefully) small things I need sorted like the rear window wiper not working and (provided all error codes are related to a faulty NOx sensor) I hope the cam- and crankshaft and lambda sensor will be fine.

My car doesn't have auto start/stop but I hear what you're saying. To be honest the car drives more than just fine and feels very nippy. Only thing is the fluctuations when idle, which I think should be the result of unbalanced fuel mixture.

Are you sure about the 6 month grace period? I did look into it and contacted Citizens Advice in regards to the missing specifications and they were indeed super helpful and informative. It is because of them I managed to get a £500 refund on the total of £4500 (excl. £450 delivery costs) and I signed a waver stating I won't pursue legal action in regards to the missing specs that were advertised, whilst explicitely mentioning I retain my 3 months parts & labour warranty plus one year AA (which I upgraded to the maximum coverage -thus also abroad).

I know garages here don't like to deal with extended warranty companies themselves (mine is Bluechip) so I'll need to pay first myself -after approval- but I wonder why dealers would advertise a 3 month warranty or at other times explicitely mention they don't provide warranty on cars older than 10 years if consumer rights extend to 6 months.

 

Give this a read:

Faulty product? How to get a refund, repair or replacement - Which?

If an item you've bought develops a fault, your refund rights depend on when you bought it and who is responsible.

www.which.co.uk

Basically, for any issues which arise during the first 6 months, the dealer must either repair the issues or refund you, unless they can prove the issue didn’t exist when you bought the car. It’s not good enough for them to just claim the issues didn’t exist - they must provide actual evidence.

Extended warranty companies can be difficult to get money out of, but it doesn’t matter what they say - if the dealer can’t prove the issues didn’t exist when you bought the car, they must fix them whether the warranty is paying for that or not!

 

Thanks again! Let's hope the issue is just small like a faulty NOx sensor or probe. A timing chain needing replacement would be more of a headache although to be honest I calculated the latter as a risk and I think even that is covered in my warranty under engine issues.

Good thing I immediately texted and saved the messages to the dealer the day after the transfer.

 

The NOx sensor is a common issue with these engines. Check the site of bimmerprofs for more info.
You can leave it like this, the only downside is that your fuel consumption is slightly higher. This sensor is used to let your injection go into extreme lean mixture (stratified charge mode). This happens only during cruising with a warm engine.
I did replace the sensor, no changes in behavior, the only change is I do 15 km to a liter instead of 14.
The best is to change engine oil, filters, sparks, and add injector cleaner, regardless of what has been done.

 

Thanks. I will have a look at bimmerprofs. I know what a NOX sensor does, I just don't know how to determine which one it is and how to replace it (or see if maybe it's just the probe that needs replacement). I've read that ignoring the issue can send your ECU into limp mode though or deteriorate the engine and as I still have full warranty I want everything fixed while I can. Also the eradic idling is something I simply don't like.

PS. Ik ben trouwens ook Nederlands maar woon en werk nu in de UK😉.

 

Ok. I could really use some help now. I took the car to a garage and the mechanic told me that -based on the crankshaft error- thus and all other error codes could be the result of a loose timing chain. Now I'm anything but an expert but in my gut I don't have a 100% faith in the mechanic. For starters, upon bringing the car he first asked me whether it had a timing chain or timing belt (?!?). As far as I know all BMW1 E87's have a timing chain so why ask? And my question whether he was a 100% certain as to whether it wasn't 'just' a matter of a faulty NOx sensor he answered he didn't know.

So here's my dilemma. I am driving this car Friday to The Netherlands. I have non-refundable tickets for the ferry plus accomodation so the car is coming either way. He can fit a NOx sensor for £393,21 incl VAT plus half an hour labor costs. Thing is I need approval from my seller's insurance. If it turns out it isn't a faulty NOX sensor but indeed a timing chain that needs replacement I won't be able to claim the latter as the first diagnosis was wrong.

So could anyone say anything based on the error codes as pictured in my first post and whether it is likely or even remotely possible this could be the result of a lose timingchain. I need to decide tomorrow...

 

It 100% isn't going to be a case of either/or. Those codes are indicating multiple, unrelated issues. The seller needs to either authorise repairs for all of it, or you need to reject the car because if they're going to tell you they won't fix all of it, you're going to be massively out of pocket.

1. 2AF2, 2AF4, 2AF6 & 2AF9 – NOx sensor has failed and needs replacing
2. 29F3 – Fuel low pressure sensor has failed and needs replacing
3. 2D29 & 2D06 – Both your MAF sensor and intake pressure sensor are reporting reduced airflow/pressure. As a starting point, I would check for leaks in the intake – parts not seated properly, torn intake boot, that kind of thing.
4. 2A99 – Either a) exhaust camshaft sensor has failed and needs replacing (unlikely), b), your timing chain tensioner needs replacing (very likely), or c), your timing chain itself has stretched (possible). Could also be both b and c together.

I think that on the 116i you can open the oil filler cap and inspect the timing chain yourself. If there is any slack whatsoever, the usual advice is not to start/drive the car at all, get it recovered. If the chain slips/snaps, you'll need a new engine!

 

Thanks so much for your detailed response. It really is appreciated given the stress levels I've been experiencing. I hear you and understand it's a matter of having the fault codes properly checked. I was hoping the garage I brought it to was able but I think I need to take it to a specialized BMW dealer or at least a garage that has extensive knowledge about this car.

I did have a look indeed if I could see the timing chain a while back after some online research but unfortunately I can't see it on my model and there is no way to tell if the tensioner has been replaced since it came without service history (the dealer told me the previous owner did most maintenance himself) but if the timing chain had been replaced I'm sure they would've put it in the advertisement as it was full of other stuff that appeared to not be present (the missing features as mentioned in my first post).

They did tell me it came with a fresh oil service and filters and an extensive 250 point checkup, rebalancing etc. prior to sale but I'm starting lose faith in that claim as it seems very unlikely all error codes popped up for the first time on the exact same day as I bought the car, so I think I've been duped (which on some level doesn't make sense given their 3 month warranty, 1 year AA cover, AA dealership promise and 50 x 5 star ratings on Autotrader.co.uk) but I also know the son is currently taking over the business so maybe he has different ethics).

Thing is I don't experience any of the usual symptoms of the timingchain going. No misfires, no sluggishness, no noise when starting which goes away after a while... Just the engine light (orange) and a tiny little bit of erratic idling but not in terms of shakes or vibrations, more in terms of revs.

In any case I've decided to not let the garage do a thing as I don't trust the mechanic and I will take my chances of driving it to The Netherlands and when I come back in two weeks I want an appointment with a specialized BMW dealer for a full diagnostic which I'll probably have to pay myself but then I have an independent judgement. The only issue now is what I will tell the seller as to the findings.

I think I will write them an email saying the findings were inconclusive as the garage didn't have the proper BMW diagnostic software and they don't have the time to look into it deeper (which is both true). As they were unable to say whether it was just a faulty NOX sensor I won't make a claim for that but explain I will have it looked at by a proper BMW dealer upon my return. My fear is that if told them all your points they would stop me from driving the car until further inspection (but don't know what they would suggest either). If they actually did or believe they did a good job inspecting and revising the car as they said they did, they shouldn't have a problem with this. A faulty NOx will only cause me some more fuel but wouldn't cause more damage in two weeks. Should the car break down then I have my extended AA and personal insurance abroad which would mean some impracticalities but no financial misery as it would then be clear the car was faulted to begin with.

I know it's subjective, arbitrary and a gamble but would you say this is a reasonable way of thinking and approach of the situation?

 

It’s much more reasonable than I’d have been in the same situation!

If you’ve got no other symptoms of chain failure (rattle being the big one) then it’s a fair approach.

Fingers crossed it keeps running ok and you have a good trip home. Let us know how it goes when you’re back and the car’s had a proper diagnosis 👍

 

Thank you so much for your help. It truly is tremendously appreciated. I know it can be annoying when a newbee just budges in on a forum and in all honesty I didn't expect so much help so really, thanks. And ofcourse I will wrap up this thread once all is sorted. I still want a (proper) BMW1 so even if I can't get this one fixed I will look for another one and come back to these forums.

One last question if I may. The mechanic also told me the rear differential might be going as it makes a wheezing sound (personally I don't hear it but still..). As for now the main issue is to make sure I get my warranty and know if the seller is liable, would you say it's fair to say if the advertisement mentioned the car has undergone extensive servicing like oil change, new filters, rebalancing etc. that they should have picked up on a problem with the timing chain and differential?

I'm confident the error codes did not just pop up for the first time the day after I bought the car so here I know I am in my rights but as for a loose timingchain or tensioner (if that's indeed the case) and a going differential I'm unsure if it's reasonable to expect a dealer should've picked this up when prepping it for sale. Even though the engine is explicitely mentioned as falling under my 3 month warranty I would also understand if -in a conflict about known faults- they could argue it's always a risk with this car and engine having done 93000 miles.

 

So.. I managed to drive back and forth to The Netherlands so 1500 miles without a problem. I've now taken the car to a proper BMW garage for a diagnosis on the engine light coming on and I'm a bit baffled.

I just came of the phone with them and they said 'it's the fuel pressure sensor and every other fault codes follows from here'. Personally I don't see how a crankshaft error could be related to this but I okayed the repair for £240 UK pounds incl. the diagnostic costs (the latter being £99). I should mention it was only after pushing them (or the lady receptionist in question) and mentioning my OBDII scanner picked up multiple codes which all can trigger the engine light, she said "in error finding we need to eliminate causes in a certain sequence first" and reasoned the other codes followed. I replied that my question was simple from my consumers perspective, the engine light comes on and I want a diagnosis from a proper BMW dealer with dito software as to why but now I feel they're essentially telling me they need to tackle the fuel pressure sensor first before they can further diagnose?!?!?

Can anyone share some thoughts on this diagnosis and the course of action? Is this 'correct' for a proper BMW dealer or are they taking the ****? I was in the understanding that their software was more sophisticated than my 80 quid OBDII scanner and that they would be able to identify all errors, even be able to look in the history logs in case the codes now wouldn't show up.
I am scared this is an endless money trap or am I exaggerating? Should my one question as to why my engine light comes on not simply be answered by one diagnostic investigation with the appropiate software? And if the engine light stays on after replacing the fuel sensor would I be right in then saying their investigation and diagnosis was incomplete and my initial request (and paid estimate) for a diagnosis still stands?

 

So now the BMW dealer admitted they can't give a blueprint or estimate about the cause(s) and all they can do is tackle one errorcode at a time, in effect meaning I would have to write a blanco cheque and hope they can solve it and wait if it was worth it. I've checked with a second BMW dealer and they confirmed this. I'm completely stuck now. Is this proces or error finding/ solving exclusive to BMW or is this the case with all modern cars and how and where can I go from here?

 

Sweet Jesus. I think at this point I'd be writing all this down and trying to reject the car back to the dealer.

 

Just to wrap it up. I sold it back to the original dealer. Settled for £2750 which is about 70% of what I paid for it. I'm still baffled about how difficult it apparently is to get a proper diagnosis but aside from the time I spent dealing with the matter, purely from a financial pov I feel okay with this deal. Essentially I drove the car for 11 months which comes down to about £150 a month give or take. From that perspective it sort of feels like a lease so all good. I now plan to spent about £8000 for a newer model with hopefully less issues. I did fall in love with BMW...

 

Glad you are happy with the result, Newbe!