Desperately seeking advice on conclusion of garage on error codes

[Wishplay]

Hello,

I'm in a bit of a jam. I'm not in the habit of rushing into a forum but for reasons I'll explain tomorrow I can use all the the advice I can get asap.

I bought a used BMW1 (E87) 116i (2.0) 2011. From day one the engine light came on. Sometimes it disappears and sometimes it doesn't show at all but if it appears (yellow) it's always the same coded which I read it out with my OBD2 scanner and on the photo I attached.

I'm no expert by any means and it's my first BMW but to me it seems it's a faulty NOx sensor or probe. The mechanic of the garage (no BMW one) reducts everything to the crankshaft error and reasons all other follow out of it. He thinks it's a lose timingchain. Now the car has driven 93000 miles and had no replacement so I understand the timingchain could be ready for replacement. However I have none of the symptoms that are associated with it. Not one single misfire, no metal in the oil, no smoke. Only thing is irratic idling and the dial on 2000rpm when idle, which to me still points to a faulty NOx sensor. I know only BMW has a specific tool or software to determine a timing chain getting too lose but this mechanic doesn't and purely reasons from that one error code and that the car feels 'off' when driving it. He also mentioned the rear differential makes a 'wheezing' sound. I feel or hear neither.

Complication in a nutshell is (I will GP come back to it in detail later when requured) is that I need to take the car with me for a visit to my home in The Netherlands this Friday and will as such do 1000-1500 miles in two weeks. I have parts and labor warranty but limited and as the mechanic essentialy says both the chain and differential need replacement I need to strategically decide whether I will have the NOx sensor replaced. Tomorrow at the latest.

Now I don't trust the mechanic as he clearly looks down on BMWs and his first question was whether my car had a chain or belt?!? As far as I know every BMW 1 E87 has a chain so why doesn't he know that? Also upon my question if he could with certainty rule out it is indeed not just a NOx sensor replacement he said 'I can't know for sure, could be but I think it's the timingchain because of the crankshaft error code.

To keep it simple and clear for now. I have no time for a second opinion as I live quite remote and there's no other garage with a free slot, I want to ask any knowledgeable member here: looking at the 8 error codes, in your subjective opinion is it likely it is the timingchain or could it be more likely that it is a faulty NOx sensor? Replacement will cost £490 for the part plus £75 labour. I know it's too expensive but again, for now I only need some advice based on the (limited) information of the error codes.

Help would be unimaginably appreciated as I need to decide within 12-24 hours.

[Wishplay]

Update: I've decided against replacing the NOX sensor as members on another forum have pointed out there could be several issues and to find the culprits a specialized BMW dealer should read it out with proper diagnostic software. So I'll write the seller the findings were inconclusive but most likely a NOx sensor needing replacement but I want a better garage to provide a better rapport. My parts and labor warranty ends on the ��13th of December so it will be tricky to get costs back and also the car could give out during my holiday which will f**k it up tremendously but then at least I have irrefutable proof the car was faulty from the start and a higher chance of getting a refund under the Consumers Rights Act. Just ruminating how to write this all in the most strategic possible way in the letter to the seller.

[WrathOTM]

Wow that is a litany of issues. You may want to shout at the mods to move your thread to the right section as this is for the 1M crowd.

My theory is you had the bolts for one of your VANOS gears snap off. When this happens you get tons of codes. BUT, I don't really know how the 4-cyl engine is as we never got them in the US.

Try babybmw dot net as they are on the same side of the pond as you.

[Wishplay]

Hi,

Thank you for your response. And I'm sorry about posting in the wrong group, I was rushed to get an answer so must've misunderstood. I will try to contact a moderator indeed. Again, sorry!

I have registers at Babyforums and others as well as I wanted as much input as possible. By now I just need to write the seller I need a second opinion from another garage and hope my car doesn't break down while on a busy scheduled holiday plus that I can either get a refund or preferably have the af fixed under my warranty.

One more question though (also applicable in the appropriate forum):

Another member gave some probable explanations about the error codes. In your or anyone's opinion, if the sensors are at fault, the timing chain or tensioner needing replacement and the mechanic also mentioning the rear differential is on its last legs (wheezing sound which I personally don't hear), do you think the seller should have picked up these issues before selling the car? Especially since the advertisement stated they've done extensive work on it like an oil change, rebalancing and a '250 point' checkup? The error codes were there from day one so it does seem likely I've been duped but I wonder if a timingchain/tensioner and differential problem should have been noted while doing a pre-sales checkup?

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.

Thanks, Martin

[Wishplay]

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 dealer 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. After pushing them (or the lady receptionist in question) she said "in error finding we need to eliminate causes in a certain sequence first". I replied that my question was simple from my perspective, the engine light comes on and I want a diagnosis from proper BMW 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 piss? 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 with the appropiate software?

[Wishplay]

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?