Engine Light After Timing/Cooling System Overhaul

[mxchris727]

Hi All,

I finally finished rebuilding the timing, VANOS, and cooling system on my 03. After a month of very slow work (making sure everything was fitted & torqued perfectly), I got to start it up last night. I primed the oil system by cranking it without the fuel pump fuse for roughly 20 seconds until the oil light went out then fired her up! No odd noises, rattles, or anything; started as usual and purred like an electric motor. I sat in the cabin for a few minutes making sure that heat was coming out of the vents and no lights were on. After restarting the car, the check engine light appeared and the idle started lowing until stalling. I hooked up ISTA and got one code: 00071 DME: Signal, camshaft position sensor, bank 1. This translates to a P0343 which is a electrical signal issue. After re-connecting the MAF and B1 CPS, the idle became strong again but the light has come back. I assume that the sensor has gotten damaged while outside of the car. I've heard that the bolt holding the sensor in can become magnetized causing the sensor to fault.

Would swapping between the left and right bank be the first point of diagnostic? After 5+ restarts, I don't have any timing-related codes thankfully! How do these become damaged in the first place? The only thing I would have done is lightly wipe it down with a towel before re-inserting.


Thanks!

[JimLev]

Yes, try swapping the sensors and see if the bank 2 codes.
As far as the bolt becoming magnetized being the problem I call BS.
I put a strong magnet right next to the tip of the sensor while looking at the waveform on my scope, no change in the signal at all.

[mxchris727]

No change after swapping; ISTA and my generic reader both show bank 1 code P0343. I'm going to tear everything apart and attempt to re-time again even though I've rotated the engine a few times after the first attempt to confirm.

On a side note, could swapping an upper timing cover cause this? I replaced my original one because I striped a bolt and it was easier just to replace the whole piece while everything was apart.

Thanks!

[mxchris727]

After unplugging bank 2's sensor, I get the same exact code on that side. This leads me to believe that moving the e-boxes out of the way may have damaged a connection somewhere. I'll probe everything tomorrow after work with the multimeter.

I've attached the pinout per TIS for reference.

[mxchris727]

Progress!

After confirming that the electrical connections were in order with no damaged wires, I removed the valve cover and found this:





Must have been too excited to get the car back together to check which direction I placed the GAS trigger wheel timing block on; it is off by ~180 degrees! So, without removing the timing covers, I slid the cam blocks back on (engine timing is perfect), loosened the trigger wheel, and re-set the position using the drill bit method through the inspection port. Can anyone confirm how accurate this is? I can feel a few degrees of play using this method and am trying to avoid a parallax error. If I remember correctly, the cam sensor is solely used for VANOS/timing referencing and allows for quite some variance as the crankshaft sensor is what actually triggers ignition timing.






Thank you!

[AquilaBMW]

I had same situation happen to me when I worked on an E38 engine. Bank 1 - off by 180 Degrees. Engine ran like crap though when this happened. In my situation, to be safe I took off the upper timing cover again, re-locked the cams in place and re-timed it. Basically locked it all down before re-installing the wheel.

[JimLev]

You should be pretty close if the drill bit is a tight fit in the screw hole.
If it throws a code loosen the nut and turn the trigger wheel a few degrees in the clockwise (looking at it) direction.

[mxchris727]

The drill bit method worked! Started it up and let it run to operating temp with no issues or codes. Thank you very much for the insight!
Of course, I turn it off and start cleaning up the garage when I hear "POP." The garage fills with smoke and two gallons of coolant went flying everywhere. I never tightened the clamp on the expansion tank - now I have hours of cleaning to do and need to buy more coolant.