Problem with BMW 1-series

Newbie93

Hi all, I am having a bit of a problem with my car. The engine light came on and the car was plugged in to check the problem and it was saying that the bank 1 oxygen sensor reading was 'slow' so a garage changed it for me. Roughly about 3 weeks later the engine light came back on this time stating that the bank 2 oxygen sensor reading was 'slow' so again, the garage changed it for me.

ANOTHER 3 weeks later, engine light came back on and I repeated getting the two sensors changed in a different garage this time. Here I am, (another 3 weeks later) driving around with the engine light on again. I simply can't bring it to another garage for them to change the sensors for the 3rd time as it is quite expensive and I had explained to the second garage originally that the sensors had only been changed previously but because the computer was telling them it was the sensors they had to go with it.

Did anyone ever experience anything similar? And I find it strange as to how the engine light always seemed to come back on around the 3 week mark. Any advice/ideas as to what the problem may be would be really appreciated. Thank you!

Leonard Hofstadter

Bank 1 and bank 2 are different sensors (for the front and back of the engine), it wasn't the same sensor that went, just very unlucky that it did in such a short space of time. You must have a 130 or 135i for it to give fault codes for two banks? The smaller engined ones would only have one bank so only one sensor - although they all have oxygen sensors for before and after the catalytic converter - but only the one before the catalytic converter matters really.

I don't know about the 1 series but with the older BMWs stuff like this has to be the genuine supplier otherwise the light will come back on again, and I wonder if the garage you've been using just put any old part into it rather than a factory spec one?

Newbie93

Yeah it's a 116, 1.6 Petrol. Both garages informed me that the parts they were using were brand new Bosch parts. Basically, the fault code for when the engine light came on the first time was 'bank 1' sensor, got it changed then engine light came on again but the fault code was for the 'bank 2' sensor so got it changed and this happened 4 times overall repeating itself in the same way so both sensors were changed twice in the space of a few months and now the engine light is back on with the problem being the bank 1 sensor again. I'm still driving the car as normal just want to get the problem sorted once and for all. I'm thinking is it even the sensors at all or could it be something else?

Leonard Hofstadter

Is it burning a lot of oil? An engine burning a lot of oil could wear out the O2 sensors very quickly but for it to do that so quickly there would be a load of other problems so that is extremely unlikely. I'm surprised a four cylinder has bank 1 and bank 2 (unless they meant sensor 1 and sensor 2). Bosch sounds right to me. Is the MAF (air flow meter) original? If it was replaced, was it replaced with a genuine part? Can't think of any other reason for them to fail so quickly to be honest - unless of course the sensors are really just a symptom of an underlying problem (and the underlying problem is causing the sensors to apparently 'fail').

khaldrogo

The original problem was not the O2 sensor........this is why I avoid diagnosing O2 sensors or cats based off fault codes, very rarely the acutal issue

Bmw123d

I can almost put money on this that ur problem is going to be down to the spark plugs ur engines is running a bit rough. These people who just change sensors on what the fault code shows up are gob****es there’s clearly a reason for it. Now don’t get me wrong some times sensors might be gone but require proper diagnosis.
But this engine u have eats spark plugs out of it and I’d be fairly confident this will be ur cure

mullingar

Does it idle smoothly at a around 800rpm when warm?

Newbie93

I put about a litre of oil in I'd say roughly about every 3 months, maybe a bit longer as the notification comes up to check oil levels and the message states to put 1L in. A couple of people said this is normal? No blue smoke or anything...

Someone else actually said it could be the spark plugs so I will get this seeing to.

In regards to it idling smoothly, I do hear a more obvious noise from time to time from the engine. Mainly when I am in a higher gear. I can't really explain it in any other way other than roughish? Again, this was mentioned to both garages. The first had said the heat shield was loose and tightened it but the noise is still there. The second garage didn’t comment.

Thanks for all your help!

Bmw123d

Newbie93 wrote: »

I put about a litre of oil in I'd say roughly about every 3 months, maybe a bit longer as the notification comes up to check oil levels and the message states to put 1L in. A couple of people said this is normal? No blue smoke or anything...

Someone else actually said it could be the spark plugs so I will get this seeing to. My only issue is i have to try a different garage again so I am hoping they don't just go by the fault code as I'm not willing to get the sensors changed for the third time and have the same problem keep arising....

In regards to it idling smoothly, I do hear a more obvious noise from time to time from the engine. Mainly when I am in a higher gear. I can't really explain it in any other way other than roughish? Again, this was mentioned to both garages. The first had said the heat shield was loose and tightened it but the noise is still there. The second garage didn’t comment.

Hope I am making some sort of sense here - thanks for all your help!

As I said I work for a bmw specialist it will be the spark plugs. These are notorious for it.

Eric Cartman

any smell of petrol off it on start or smoke ? if it was running rich / burning oil it would eat sensors quickly.

Del2005

Newbie93 wrote: »

I put about a litre of oil in I'd say roughly about every 3 months, maybe a bit longer as the notification comes up to check oil levels and the message states to put 1L in. A couple of people said this is normal? No blue smoke or anything...

Someone else actually said it could be the spark plugs so I will get this seeing to. My only issue is i have to try a different garage again so I am hoping they don't just go by the fault code as I'm not willing to get the sensors changed for the third time and have the same problem keep arising....

In regards to it idling smoothly, I do hear a more obvious noise from time to time from the engine. Mainly when I am in a higher gear. I can't really explain it in any other way other than roughish? Again, this was mentioned to both garages. The first had said the heat shield was loose and tightened it but the noise is still there. The second garage didn’t comment.

Thanks for all your help!

Why are you going to several garages? A new garage will have to start with the sensors again, as they can't/won't stand over someone else's work. One you went to before will have to follow the next steps to debug your car.

Nuw

I'd agree with Del2005 on this, with repeating failures like this, the original mechanic would be the one to talk to. If it's a trust issue, tell us where about you're located and I'm sure someone will be able to recommend a decent mechanic to you, possibly a beamer specialist with experience with that particular issue.

mullingar

I wonder if the pcv valve is also stuck closed so the oil is being pushed out with crankcase pressure. These are built into the rocker cover and can be carefully clipped open to clean.

Leonard Hofstadter

PCV problems would give fault codes P0171 and P0174 system too lean bank 1/2 (at least that's what happen on other BMWs when the breathers get blocked).

Newbie93

Meant to comment on this earlier - got the spark plugs changed a good while ago now - no engine light yippee. Thanks again 😊

Bmw123d

Newbie93 wrote: »

Meant to comment on this earlier - got the spark plugs changed a good while ago now - no engine light yippee. Thanks again 😊

So as I said all along ya. It’s nearly always the plugs on that engine. And they will have to be changed almost every service. There a disaster

Newbie93

Bmw123d wrote:

So as I said all along ya. It’s nearly always the plugs on that engine. And they will have to be changed almost every service. There a disaster

Literally just as I get the comment up typical, so this morning heading to work engine light came one, now the car is due a service, just oil and air really according to my boyfriend as he did the last service, he said to ask should the sensors be changed at the same time as the spark plugs, he said he's a bit at a loss with it but trying to get it right

Bmw123d

Newbie93 wrote: »

Literally just as I get the comment up typical, so this morning heading to work engine light came one, now the car is due a service, just oil and air really according to my boyfriend as he did the last service, he said to ask should the sensors be changed at the same time as the spark plugs, he said he's a bit at a loss with it but trying to get it right

What sensors are u on about