E46 320iSE - faulty inlet camshaft sensor - why does this...
Discussion
...cause occasional engine hesitation/ stalling, which disappears once the fault code is reset, but them reappears again after a couple of hundred miles? I would have thought that this sort of fault should not 'correct itself' until the faulty sensor has been replaced??
Is the car safe to drive? I'm planning on getting the repair done in the New Year, as there does not seem to be any urgent need at the moment - but I stand to be corrected!
All advice appreciated!!
Is the car safe to drive? I'm planning on getting the repair done in the New Year, as there does not seem to be any urgent need at the moment - but I stand to be corrected!
All advice appreciated!!
LordGrover said:
I had mine changed ASAP because I was told at some point it'll fail completely and leave me stranded. May well be okay but be aware it may decide it's had enough.
Can't remember how much but it wasn't expensive.
Thanks for the advice! Think I'll get my car booked in at a good specialist (maybe 'Birds') and get it sorted. Can't remember how much but it wasn't expensive.
The fault encountered is an intermittent fault at present, not a constant fault, so it is only occasionally failing to operate correctly.
Once the camshaft sensor has it's temporary "glitch", the cars ECU is most likely storing this as a running condition along with a fault code and is controlling the engine as best it can to counter the problem in order to keep the car running (basically it's trying to counteract what it sees as an ignition fault. The fact that the fault is only a momentary one does not get registered with the ECU, as far as its concerned, once the fault is seen, its always there).
The car doesn't reset the fault each time the car is switched off and back on again, it remembers the fault is there and continues to try counteract it.
When the fault is reset (but not fixed), the car is running normally again because at the time of the reset the camshaft sensor is functioning correctly. It hasn't actually "fixed" itself as such, it's just not playing up at that particular time. After a couple of hundred miles however, the temporary "glitch" returns and you're back to square one.
If the sensor fails completely (which it can do at any time once it starts to become faulty!), the car will fail to run as the ECU has no way of knowing the camshaft position in relation to the crank position and so cannot operate the ignition timing safely.
As has been said, it's not that expensive to replace and is quite an easy DIY job (SEE: http://forums.roadfly.com/forums/bmw/bmw-3-series-... ).
My best piece of advice concerning this issue is to always use a genuine BMW part rather than a pattern part as some of the copies can be of dubious quality and can fail after only a few months.
Hope this is of some help.
Once the camshaft sensor has it's temporary "glitch", the cars ECU is most likely storing this as a running condition along with a fault code and is controlling the engine as best it can to counter the problem in order to keep the car running (basically it's trying to counteract what it sees as an ignition fault. The fact that the fault is only a momentary one does not get registered with the ECU, as far as its concerned, once the fault is seen, its always there).
The car doesn't reset the fault each time the car is switched off and back on again, it remembers the fault is there and continues to try counteract it.
When the fault is reset (but not fixed), the car is running normally again because at the time of the reset the camshaft sensor is functioning correctly. It hasn't actually "fixed" itself as such, it's just not playing up at that particular time. After a couple of hundred miles however, the temporary "glitch" returns and you're back to square one.
If the sensor fails completely (which it can do at any time once it starts to become faulty!), the car will fail to run as the ECU has no way of knowing the camshaft position in relation to the crank position and so cannot operate the ignition timing safely.
As has been said, it's not that expensive to replace and is quite an easy DIY job (SEE: http://forums.roadfly.com/forums/bmw/bmw-3-series-... ).
My best piece of advice concerning this issue is to always use a genuine BMW part rather than a pattern part as some of the copies can be of dubious quality and can fail after only a few months.
Hope this is of some help.
4rephill said:
The fault encountered is an intermittent fault at present, not a constant fault, so it is only occasionally failing to operate correctly.
Once the camshaft sensor has it's temporary "glitch", the cars ECU is most likely storing this as a running condition along with a fault code and is controlling the engine as best it can to counter the problem in order to keep the car running (basically it's trying to counteract what it sees as an ignition fault. The fact that the fault is only a momentary one does not get registered with the ECU, as far as its concerned, once the fault is seen, its always there).
The car doesn't reset the fault each time the car is switched off and back on again, it remembers the fault is there and continues to try counteract it.
When the fault is reset (but not fixed), the car is running normally again because at the time of the reset the camshaft sensor is functioning correctly. It hasn't actually "fixed" itself as such, it's just not playing up at that particular time. After a couple of hundred miles however, the temporary "glitch" returns and you're back to square one.
If the sensor fails completely (which it can do at any time once it starts to become faulty!), the car will fail to run as the ECU has no way of knowing the camshaft position in relation to the crank position and so cannot operate the ignition timing safely.
As has been said, it's not that expensive to replace and is quite an easy DIY job (SEE: http://forums.roadfly.com/forums/bmw/bmw-3-series-... ).
My best piece of advice concerning this issue is to always use a genuine BMW part rather than a pattern part as some of the copies can be of dubious quality and can fail after only a few months.
Hope this is of some help.
Many thanks for that comprehensive reply! Most useful, in fact. Once the camshaft sensor has it's temporary "glitch", the cars ECU is most likely storing this as a running condition along with a fault code and is controlling the engine as best it can to counter the problem in order to keep the car running (basically it's trying to counteract what it sees as an ignition fault. The fact that the fault is only a momentary one does not get registered with the ECU, as far as its concerned, once the fault is seen, its always there).
The car doesn't reset the fault each time the car is switched off and back on again, it remembers the fault is there and continues to try counteract it.
When the fault is reset (but not fixed), the car is running normally again because at the time of the reset the camshaft sensor is functioning correctly. It hasn't actually "fixed" itself as such, it's just not playing up at that particular time. After a couple of hundred miles however, the temporary "glitch" returns and you're back to square one.
If the sensor fails completely (which it can do at any time once it starts to become faulty!), the car will fail to run as the ECU has no way of knowing the camshaft position in relation to the crank position and so cannot operate the ignition timing safely.
As has been said, it's not that expensive to replace and is quite an easy DIY job (SEE: http://forums.roadfly.com/forums/bmw/bmw-3-series-... ).
My best piece of advice concerning this issue is to always use a genuine BMW part rather than a pattern part as some of the copies can be of dubious quality and can fail after only a few months.
Hope this is of some help.
i had similar probs with my e39. http://pistonheads.com/gassing/topic.asp?h=0&f... sensor problems
long and short of it use only BMW parts.
however mine would run with the sensor disconected.
long and short of it use only BMW parts.
however mine would run with the sensor disconected.
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