Cautionary tale for all Porsche Cayenne V8 owners

February 2nd, 2011

For PCP members buying or owning a 2003 to 2008 Porsche Cayenne V8 please be aware of some of the glaring faults due to design and materials errors by Porsche: 

1)     If your Cayenne is running rough or has misfired while accelerating hard then the problem is simple, the coil packs are cracked and the spark is grounding to the engine block. Just buy new coils and the car will run smooth. The coils are not expensive if bought from USA or UK, about 27 pounds each. Porsche now recommends to change the coils every 40,000 km or every four years.  In the USA, they are refunding the coil costs to the owners. Most UK Cayenne owners now treat coil packs as a service replacement item. 

2)     Check your Cayenne’s water cooling pipes located under the air intake. You will need a flashlight and a mirror on a stick to see these pipes, as they are not easily visible.  If they are still the black plastic ones, they must be changed. 

If the pipes are plastic you will suffer a major coolant leak. It will happen, it is just a matter of time. So don’t put off this job, and order the parts from USA or UK; cost is around 500 USD for the total kit (Porsche original parts).  


The right picture shows the kit from the UK.

There are the three upper pipes and under that the fourth bigger one. My key is inserted in the 8” long split caused by failure of the plastic pipe. Porsche has designed and offers the kit to “upgrade” and discontinued the old plastic pipes. The 2009 Cayenne has this aluminium pipe kit installed as standard at the factory. 


The left picture above shows the old plastic pipes removed and the picture on the right shows the new aluminium pipes installed. The kit is made so the back water distribution manifold doesn’t need to be removed. The old design required to remove the engine. The repair is relatively easy for a Porsche mechanic to do. The mechanics did the job in a day. They carefully cleaned and put everything back paying special attention to inlets as it is possible to drop something into the cylinders (ouch). I would advise to anyone owning a Cayenne S or Turbo to get this done as soon as possible as a precaution. I have seen the state of the pipes removed, all were cracking and obviously plastic is the wrong material and will 100 per cent fail. Sometimes coolant leaks slowly and may leak straight into the starter motor and then down into the transmission, in the course damaging the transmission seals, creating making another big job to replace these seals. 



  Mark Taylor



PS.  I have a spare set of pipes, if anyone is interested contact me at