How to Replace the Camshaft Position Sensor in a 2000 BMW 528i

I knew I had a problem. I had just stopped to fill the tank. I went to restart the car, and it took a few tries. (HINT: the engine was warm).

As I pulled away, the car stalled. To keep it from stalling, I had to give it gas. And as I drove away, I had no power. I had no acceleration at all.

As I limped home, I noticed the CEL (check engine light). I stopped at a light, and the car stalled again.

The next day, the car seemed normal, except the CEL was still on.

I dropped the car at the shop, but they couldn't find anything wrong.

Over the next week, the car's symptoms were intermittent. The CEL was sometimes on, sometimes off.

Finally, I had five minutes of downtime. I put my OBDC reader on the car ... p0340 ... camshaft position sensor.
The camshaft position sensor (CPS) is a magnetic sensor. It sends a signal to the car's computer, relaying information about camshaft speed and position (duh). The computer uses this information to determine the amount of fuel to send the engine, and when to fire the engine. There are two camshaft position sensors on the e39, an intake sensor and an exhaust sensor.

From what I read online, the CPS seems to fail pretty frequently, especially on BMWs. The intake sensor seems to fail more.

Finding a replacement CPS online was easy. Several folks on the forums recommended buying OEM as some had problems with parts from less reputable manufacturers. I decided to spend double ($140) and buy the part at the local dealer. I was in a hurry. I had a free day, a rarity for me. I asked the parts guy for a drawing which he was able to print out from his computer.

Replacing the CPS took me a couple of hours. Would have been a lot less, had I known what I was doing. I took pictures for posterity


First, I had to locate the old CPS. It was well hidden. To gain access to the CPS, I had to remove the engine cover, disconnect a hose and remove the oil filter and the vanos solenoid (a cylindrical silver object).





To remove the vanos solenoid, first unplug its cable. Press down on the metal clip and gently unplug the cable. Then use a wrench on the body of the solenoid. The solenoid has an O-ring. Don't lose it.




NOTE: If you remove the oil filter, put a rag in its place. Better to drop something onto the rag than into the filter chamber. This is a tip I learned on line.

Then I had to trace the cable from the old CPS to the socket where it plugs in. I put a loop on the end of a wire hangar and used it to trace the cable. The socket is well hidden, deep within the engine compartment. You may get a glimpse, but really, you must feel for it. Once you find the socket, press down on the metal clip to release the connector. It comes out easy. No force.




Next, I removed the old CPS, using a 5mm Allen wrench and removed it from the car. Don't forget to remove the old o-ring. [I forgot to take a picture of this].

Then, I oiled up the new o-ring, put it on the new CPS, and maneuvered it into place. This sounds easier that it was, since there is barely enough room to get it in place.



After I secured the sensor end of the CPS, I fished the cable around some hoses and cables, behind the oil filter chamber, and into position near the connector. When you connect the cable to the connector, the side of the connector with just one notch faces down. The side with two notches faces up. Again, you do this by feel, since you don't really get to see any of what you are doing. If my hands had been any bigger, it wouldn't have worked.

Then, I put it all back together. I put back the vanos solenoid, including its O-ring. I reconnected the black hose. I reinstalled the oil filter.

I started her up. No terrible noises. No oil shooting from the engine compartment.

I took her for a spin. No symptoms. Great acceleration. No check engine light.

Very satisfying.