Perhaps a fuel problem. How much gas showing on your gauge

Sent from my SPH-L710 using Bimmer App

 

Also I hope you didn't buy a cheap maf sensor. If you did, this will be lesson number one. When it comes to electronic parts or sensors must get oem

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Before jumping into MAF, I suggest you look at the intake boots. See if they are torn or have crack on them.
Replace them. About $20 each, there are 2.
Check/change fuel filter, if there are no cracks on the intake boots.
Your problem looks like it is due to vacuum leak or fuel pressure regulator(which is built into fuel filter for us with M54 engine).
Also for a 325, we can use seimens MAF from hyundai. Its the same part, costs less because its not stamped as BMW. Search this forum for more info.

I believe the airbag light you are describing is due to the pretensioner failing.
Most of the time it is just the wire(harness), if the pretensioner pyro charge hasn't been deployed. The wire is around $16. Search Tim's DIY. He has the part number there.

You might want to clean the ICV and Throttle body as well while replacing the boots. This will help you isolate the problem area.

Get a BMW scanner 1.4, that will be useful to diagnose problems and not run to a mechanic everytime you have a SES or airbag light. You can also reset/readapt the DME with it. Most of the times when you change the sensors, its recommended to readapt the DME.

 

The bouncing revs problem sounds likely to be a vacuum leak. The lower intake boot is usually the culprit on these cars. The intake camshaft position sensor also causes this to happen when it goes bad, but will usually throw a code.

 

I agree with Importjunkie regarding a vacuum leak. When the car stalls does the check engine light come one?

 

Yes the check engine light does come on when the car stalls. These problems were not present before the old engine packed in, so does that not mean that these problems are from parts within the new engine that has been put in? Or could the bottom end going have upset the ancillaries aswell?
I will probably take the car back to the place that fitted the engine as i have a 6 month warranty but what shall i say? And does everyone think it wont be a problem with the engine itself?
Also any other feedback on the airbag light at all? The codes read are showing the pre-tensioner is at fault, has anyone heard of this resistor stopping the light from showing?

 

And no the MAF sensor was not bought cheap, came from BMW themselves for over £100.

 

that's actually pretty cheap. Nice. well, not cheap as in china cheap but affordable. anywho, sounds like you have oil gunking up your spark plugs, causing that erratic idling. thank me when you change them out.

 

Is there any chance this could be an ECU problem? I was told when i was handed down the car that when he bought it, the lambda sensor had been deliberately cut by the previous owner. I was the one that had a new sensor put in and it was 3 months down the line that the engine packed up.

 

no. very rare case that it would be your ECU. even if they cut the sensor, as long as you have it all connected it up correctly, you're ok. which sensor was it? if it was any of the post cat sensors, you're in great shape.

 

In reference to your second problem. Just type "E46 airbag bypass" in the search box on eBay. There will be a sensor that just plugs in to where the old sensor was. The airbag light won't just go off though, it has to be reset. The part is not expensive at all and it works. The shop may charge a diagnostic fee to reset it also.

 

This is what it looks like.

 

And this will still work even with the problem being the pre-tensioner and no actually the airbags themselves?

 

It seems like these bypass units are only for the common passenger occupancy sensor problem? Thats not going to work for the seatbelt pre-tensioner is it?

 

Had the diagnostics machine plugged in today and the code coming back is:
P0011 A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1))

Apparently this is a timing issue however the garage assured me they got the timing done perfectly. Any chance this could have anything to do with the solenoid?
And its confusing me how this can cause the irratic reving when between 1000 and 2000 revs.

Any ideas? Would be very appreciated? Also still scratching my head on what to do with this airbag light

 

Probably has to do with the solenoid since a faulty position sensor would be P0340

 

Probably a stupid question but if I had a complete engine fitted with no ancillaries, would the solenoid have been replaced aswell or is that classed as an ancillary?

 

The shop telling you that you needed to keep any sensor unplugged to run it, is kind of a red flag right there. Did you ever get this situation resolved?