CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

!997 BMW 328i

Just had my cam position sensor replaced, the code can be cleared but comes back in a very short time. When replacing te sensor does the battery need to be disconnected, and if it was not could it destroy the sensor? Can the sensor be tested out of the car, if so what is the procedure?

  1. No, the battery does not need to be disconnected.
  2. The cam sensor is probably not the culprit. Might be the VANOS seals.
    A cheaper alternative to replacing the whole unit:
    http://www.beisansystems.com/index.html

Thanks for the information, I don,t have a lack of power and dont recall any surging under 3000 RPM, the vehical has over 100,00 miles, the cam sensor diagnostic code has not been on too long, would the Vanos failure give me the same code?