Any way to test crank or cam position sensor?

[mr2mike]

The sensor isn't dead yet.
Symptom is cranks a bit longer on cold starts suddenly.
Maybe caught a few misfires or stumbles at highway speeds.
Not ruling out fuel issues but wondering if you can get a resistance or lack of it on a slowly failing cam position sensor?
BMW X3
My guess is not.

[FunWheelDrive]

Everytime I've seen a failed or failing camshaft position sensor the symptom was the car would start and run for 5-10 seconds then shutoff. Check engine light present.

Any check engine light on?

If your car uses a hotwire MAF I would try cleaning the MAF out. Cold start issues can be caused by a faulty coolant temperature sensor.

[JustinL]

If a crank sensor fails, usually the car won't start at all and if it does it will run like garbage. The tach will drop to zero or jump around like crazy. If the tach is stable, then it's probably not the crank sensor. Depending on how the ECU handles a failed cam sensor, it could still run. Either of these failures will show up in the OBD2 codes. Pull the codes and that will give you a better starting point.

[mr2mike]

Good points.
No codes. Cleaned my maf with sensor cleaner.
Cleaned up my VANOS solenoids (bmw valve timing adjusters).
Reset the adaptations which made the best improvement on cold drivability (no more lag or slow gear shifts)

I'll check the coolant temp sensor. Had diagnostics hooked up when car was hot for the adaptation reset but haven't seen how the coolant sensor behaves at cold starts.

Like I said, this isn't showing major symptoms yet but I bet come winter I may see something more creep up.
Guess I can also wait until a code pops up.

[Kloubek]

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If a crank sensor fails, usually the car won't start at all and if it does it will run like garbage. The tach will drop to zero or jump around like crazy. If the tach is stable, then it's probably not the crank sensor. Depending on how the ECU handles a failed cam sensor, it could still run. Either of these failures will show up in the OBD2 codes. Pull the codes and that will give you a better starting point.

I second this line of thinking.

Most if not all vehicles I've seen with a cam sensor out simply won't run. And if you COULD get it to run, it would be very noticeable.

[mr2mike]

Thanks. Guess I'm paranoid as I've had this sensor go on me in the past and it's no fun.

Other cars (Nissan and Infiniti). Just to clarify.

[legendboy]

Need an oscilloscope to check the sensor is functioning properly

[ThePenIsMightier]

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Thanks. Guess I'm paranoid as I've had this sensor go on me in the past and it's no fun.

Other cars (Nissan and Infiniti). Just to clarify.

To quote Killramos, "just Nissan things".

*Although it's not really a chronic problem

[cancer man]

Take it to a Mechanic..

[mr2mike]

Booted up some bmw software INPA and ran the motor.
The cam positions seem within range and most things have been sorted.

What I did was delete all adaptations within the ecu and did a relearn on crowchild tr at night.
I'm sure rush hour traffic will relearn into it again and I'll do the procedure again.