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This guide provides step-by-step instructions on how to remove and replace the coolant overflow reservoir (coolant expansion tank) on Porche Cayenne.

Table of Contents

This guide also applies to Volkswagen TOUAREG 2004-2010 and Audi Q7 2007-2015 as these cars are built on the same platform.

The common problem is that the coolant reservoir cracks and develops a leak, leading to coolant loss and engine overheating. Another problem with these units is that the level sensor may fail and requires the replacement of the whole coolant tank assembly.

What you will need

Before you start

  • Allow the engine to cool down for a couple of hours
  • Use gloves.
  • Do not open the overflow tank while the engine is hot.


  1. Park, the vehicle, turn off the engine, and let it cool down. Allow the engine to cool down for a few hours.parked porsche
  2. Pull the hood release under the dashboard and open the hood
  3. Locate the coolant reservoir on the passenger side of the engine. The coolant expansion tank is black.porsche cayenne vw touareg audi q7 coolant overflow reservoir
  4. Remove the black plastic trim that goes around the engine. There is a T25 Torx screw below the windshield washer fluid cap. Open the cap to access this bolt.engine trim
  5. Remove the air intake pipe. Align the screw notch with the small channel. Next, pull out the screws. Once you remove both screws, you can disconnect the air inlet.remove filter housing
  6. Unclip the metal retainers for the air filter housing.remove clips air filter
  7. Remove the air filter housing completely. There is a 10mm bolt that holds the housing to the frame.remove filter housing
  8. Use a 16mm socket to remove the torque arm bolt.torque rod boltNext, remove two 16mm bolts that secure the torque arm bracket to the frame. One bolt is towards the back of the bracket.16mm bolt to frame remove to accesss coolant tankOnce you remove the torque arm bracket, you will see an exposed T30 bolt that secures the overflow tank to the frame.
  9. Locate the connector that plugs into the temperature sensor. Press on the connector clip, then pull it off.connector
  10. Disconnect all the hoses from the overflow tank. Use needle-nose pliers to release the clamps.hose to coolant tankAs you disconnect one hose at a time, keep a container nearby to collect all the coolant that comes out of the coolant tank.unhook hose On Turbo models, there is a power brake vacuum pump next to the reservoir. You will need to remove this as well. To remove the brake vacuum pump, you will need to disconnect the hose that goes to it, the electrical connector, and two 10mm bolts.
  11. Remove the T30 Torx screw that secures the tank to the frame.overfllow tank bolt
  12. Disconnect the hose on the bottom of the tank.
  13. Install the new coolant reservoir in reverse order. Pay close attention to the bracket on the bottom side of the tank. The new coolant tank needs to slide in the bracket on top of the porsche coolant reservoir
  14. Reconnect the rest of the hoses.
  15. Add genuine engine coolant.

If needed, bleed the cooling system to get rid of air pockets that remain in the system.


  • 2003 Porsche Cayenne 
  • 2004 Porsche Cayenne 
  • 2005 Porsche Cayenne 
  • 2006 Porsche Cayenne 
  • 2007 Porsche Cayenne 
  • 2008 Porsche Cayenne 
  • 2009 Porsche Cayenne 
  • 2010 Porsche Cayenne 
  • 2003 Audi Q7, VW Touareg 
  • 2004 Audi Q7, VW Touareg 
  • 2005 Audi Q7, VW Touareg 
  • 2006 Audi Q7, VW Touareg 
  • 2007 Audi Q7, VW Touareg 
  • 2008 Audi Q7, VW Touareg 
  • 2009 Audi Q7, VW Touareg