Need Help with BMW Crankshaft Position Sensor Issues

Technical Discussions
1

I’m having some trouble with my BMW related to the crankshaft position sensor (CPS), and I’m hoping to get some advice from the community. Here’s what I know so far:

Symptoms

  • The check engine light is on.
  • My car occasionally has trouble starting, especially after it’s been running for a while.
  • I’ve noticed a rough idle and some stalling at stoplights.

What I’ve Tried

  • I’ve checked the battery and alternator; both seem fine.
  • Tried clearing the codes, but the light comes back on after a few days.
  • I’m considering replacing the crankshaft position sensor myself but wanted to get opinions first.

Questions

  1. Have you experienced similar issues with the CPS in your BMW?
  2. How do I diagnose if the crankshaft position sensor is truly the culprit?
  3. Is it advisable to replace it myself, or would it be better to take it to a mechanic?

Any insights or personal experiences would be greatly appreciated! Thanks in advance.

2

I’m having similar issues with my BMW. One clear sign for me was the engine misfiring during acceleration. Has anyone else experienced this?

7 Likes
3

Absolutely! My 3 Series started stalling unexpectedly, which pointed to a crankshaft position sensor problem. It’s quite unsettling when it happens.

1 Like
4

For me, the car would sometimes refuse to start. It took me a while to connect it to the sensor issue. Very frustrating!

4 Likes
5

That’s so true! I only figured it out after I replaced several other parts for what I thought was the real problem.

6

I dealt with a lot of unexpected stalling, especially at stoplights. It was embarrassing when my car just shut off in traffic!

1 Like
7

Haha, I can relate! It’s like you’re just waiting for the right moment to stall with everyone watching.

8

When my sensor started failing, it caused a bunch of weird issues with my dashboard lights too. Has anyone encountered that?

9

Yes! My check engine light was constantly on, and it turned out to be the crankshaft position sensor.

10

A simple test is to check the connector and wiring first. Sometimes it’s just dirty contacts causing the issue. Easy fix!

8 Likes
11

Great tip! I’ll check mine before spending money on a new sensor.

12

I read online that a bad crankshaft position sensor could also affect fuel efficiency. Has that been anyone’s experience?

13

For sure! I noticed my MPG dropped significantly right before the sensor started failing.

14

If you experience these symptoms, don’t delay diagnosing the issue. It could lead to more costly repairs down the line!

15

That’s good advice! Preventive action is often the best route with these cars.

16

Just keep in mind that replacing the sensor myself resulted in a few scraped knuckles. Worth it for the savings though!

17

Haha, that’s the price you pay for being a DIY mechanic! But you’re so right; the savings make it worth it.

18

Diagnosing crankshaft position sensor issues starts with checking error codes using an OBD-II scanner. Look for codes like P0335 or P0336 that indicate sensor problems.

19

That’s a great start, Scott! After checking codes, you should inspect wiring for any damage or corrosion. A multimeter can help you test the sensor’s resistance and voltage too.

20

Make sure you have a basic toolbox ready: OBD-II scanner, multimeter, socket set, and a torque wrench for reinstallation. Following proper torque settings is crucial for the new sensor!