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Mini Cooper 2001-2006: How to Replace Crankshaft Position Sensor

Changing out the crankshaft position sensor, or even just putting on a new O-ring to solve oil seepage, on the Cooper is a common chore. Getting to where it's located is a little bit tougher, but completely doable by the DIYer.

By Paul Johnson - June 29, 2016

This article applies to the Mini Cooper (2001-2006).

The crankshaft position sensor (CPS) is a sensor that plugs into your engine to monitor the rotation of the crankshaft (RPM), which is then used to control ignition timing to optimize engine performance, fuel economy and general smoothness and tractability. Over time, the CPS can fail, meaning that the engine's computer cannot accurately sense the crankshaft's speed and location (what "point" it's at in it 360* rotation). This repair is pretty simple. Out with the old and in with the new. This doesn't mean it isn't exactly easy. Getting to the CPS can be a little bit of a chore and if you don't want to put the vehicle in front end maintenance mode, you have to do the repair blind. This should not be a deterrent, as doing blind repairs will happen from time to time. It is very cramped, but can be accomplished, so don't be afraid of it.

Mini Cooper 2001-2006: How to Replace Crankshaft Position Sensor

Materials Needed

  • Jack and jack stands
  • Phillips screwdriver
  • Ratchet and 10mm socket
  • Shop rag

Step 1 – Remove skid plate

Place the vehicle up on jack stands (Figure 1). It isn't necessary to put it up on four to make it level, but doing so makes it easier to access what you need to get to.

(Related Article: How to Jack Up Your Car - NorthAmericanMotoring.com)

Jack stand placement MINI COOPER S R53 R52
Figure 1. Jack stand placement.

Once the vehicle is suspended, remove the three 10mm bolts and two Phillips head screws, which attach the bumper to the skid plate. Remove the two connectors at the back, which connect the skid plate to the vehicle using a 1/2 turn to accomplish. Remove the skid plate and place safely under the vehicle out of the way.

Step 2 – Locate and remove CPS

From the bottom, reaching up behind the A/C compressor, locate the CPS wiring connector and disconnect (Figure 2). The clip is the same clip as what is used on the coil pack connector, so practice on it a couple of times to understand the mechanism. Once the plug has been disconnected, remove the single 10mm bolt which holds the CPS in place. Wiggle the CPS to pull it out.

Crankshaft Position Sensor Location MINI COOPER S R53 R52
Figure 2. Crankshaft position sensor (CPS) location.

Step 3 – Replace CPS

Place new O-ring (if not already installed) onto new CPS. Coat the O-ring with a thin layer of clean engine oil. This will aid in installation with less chance of distortion or damage to the O-ring. Wiggle the new CPS into position. Replace 10mm bolt to hold it in place. Clip and secure wiring harness to the sensor. Place skid plate back into position. Replace two rear connectors, two outer Phillips head screws, and three 10mm bolts to secure skid plate in place. Jack up car and remove jack stands.

Featured Video: Mini Cooper Crank Sensor O-Ring Replacement

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