Camshaft position sensor

**19lanemitchell** · 09-17-2020, 06:13 PM

Hi, I have no idea how to use this app so if you see this please inform me somehow how to fix this problem. I own a 2000 BMW 323i with the 2.5l I6. I replaced the cam shaft position sensor in it. When I got it all back together it ran like crap. Sounded way out of time and my scan tool which is a Performance Tool (model number: W2977) told me I had a P1397 code. Upon looking this up it tells me it’s a cam shaft position sensor/fuel rail problem. Anyone else have this problem and if so how should I correct it?

**shogun** · 09-17-2020, 07:20 PM

Moved from E46 Common Problems and DIY Fixes to E46 forum

**harrier** · 09-17-2020, 10:06 PM

Originally Posted by 19lanemitchell

Hi, I have no idea how to use this app so if you see this please inform me somehow how to fix this problem. I own a 2000 BMW 323i with the 2.5l I6. I replaced the cam shaft position sensor in it. When I got it all back together it ran like crap. Sounded way out of time and my scan tool which is a Performance Tool (model number: W2977) told me I had a P1397 code. Upon looking this up it tells me it’s a cam shaft position sensor/fuel rail problem. Anyone else have this problem and if so how should I correct it?

Out of curiosity, why did you replace the sensor? And what brand did you replace it with?

Often, the VANOS pistons are the cause of the camshaft sensor codes. The actuator or the actual VANOS piston gets gummed up, and when the solenoid is activated to move the VANOS, it doesn't. The Camshaft sensor goes WTF!! and throws a code.

The exhaust solenoid is to the left of the thermostat, and its connector is on the same harness branch as the exhaust camshaft sensor. Remove it, being careful to put a rag under to keep the oil off the belts and AC compressor. Test the solenoid by attaching 12v to the contacts and making sure the pin extends (they rarely fail). If it does fail, pick one up at a junkyard or message me and I have a few around.

Then remove the piston from inside the VANOS housing through the opening where you unscrewed the VANOS. There will be a plastic piston and a spring, keep track of them. Clean the piston and the opening thoroughly, then replace the piston (spring first) and the screw in the solenoid firmly (don't crank it, just get it in firm). Remember to reattach the harness!

If the above doesn't work, then you may have to service the VANOS as the camshaft piston may be binding or have contamination. Buy the Beisen seals ($60) and replace them. In fact, you should do it anyway if it has never been done as they start failing at around 30k miles.

Good luck!

**19lanemitchell** · 09-17-2020, 10:37 PM

Thank you, currently dark out an I’m at work so will be sure to do all this in the morning, the cam sensor code is still coding out, so I’ll try an VANOS unit. But the idling problem I’ve traced to a faulty intake seal causing it to miss fire like it does. But thank you again!