Cayenne Turbo

Coolant Leak from Thermostat Housing on Porsche Cayenne Turbo

Problem Description and Possible Solution

A coolant leak may develop at the thermostat housing, under the intake manifold. Our technicians tell us that revised parts are available to correct this concern.

Problem Data
RepairPal Verified
Average mileage: 97,720 (90,000–103,000)
6 model years affected: 2003, 2004, 2005, 2006, more2008, 2009
13 people reported this problem
Viewing 1 - 5 of 5 comments
My Cayenne Turbo S has had 2 repairs done for the same problem with the coolant pipes, intake socket and the T part on the turbos. The first time the shop @ dealership did not replace the plastic pipes with aluminum like they are doing with the 1st generation pre 2008 models. Plastic ones aren't even available as replacement part - Porsche requires owners to purchase an "upgrade" OEM kit because the plastic ones are known to fail.
ALL Cayennes (1st and 2nd generations) have PLASTIC pipes just like the 2003-2006s. The only difference is that the configuration changes with the plastic pipes now running in one large pipe over the valley of the engine, not on top the engine valley itself, still situated over the starter as well.
They replaced the intake socket, etc. the 1st time and the crossover pipe into the bridge at the back of the engine near firewall on the 2nd repair. Mine also had to have the starter, battery and coils replaced while dropping the engine on the 2nd repair. Ridiculous that this is still happening just like the pre 2008s. PCNA/Porsche AG should recall these vehicles since they have known about these ticking time bombs all along. Who puts plastic pipes everywhere (and over the starter, really?) in a high performance engine especially the turbos?????
Great resources on and Just search "coolant pipes" and make sure you have lots of time to read.
Check out Cayenne coolant pipe failure database info:
In 2010, I bought a preowned '08 Cayenne Turbo at approximately 40K miles. Prior to delivery, I paid the local Porsche dealership to run a system check and confirm that the vehicle was mechanically solid and free of defects. Subsequently, they performed a repair on the coolant pipes (still under factory warranty) and assured me it was in excellent condition to purchase. I wasn't aware of the coolant pipe/leak(s) issue at that time.
Fast forward to 2013. Starter was making noises and not working 100% of time, so I brought vehicle to the same Porsche dealership who had been servicing it since 2010. I was informed that my (previously corrected) coolant pipes had a leak & required repair. I reviewed my previous invoice from original "repair" under warranty at ~40K miles and it appeared to be the same issue, same part numbers, etc. OK... I received another call a few days later informing me that now my Cayenne has a "second coolant leak" at the crossover pipe toward the back of the engine near the firewall. This required the removal of the engine in order to repair. The service advisor and the Porsche technician told me that the second leak occurred because the "first" repair (actually the SECOND, if you consider it was already repaired under warranty at 40K miles) then properly pressurized my coolant system, thereby causing the next leak, requiring the "next" repair. Knowing that the '03-'06 Cayennes (PCNA didn't deliver any '07s to USA markets) have well known and documented coolant pipe defects resulting in a Class Action Lawsuit against PCNA (7/2013; see:, I inquired about the dealership utilizing their "Goodwill Budget," which all dealers may access, and the canned answer from the service manager was "no."
Bottom line is that I had to pay for TWO coolant leak repairs, in addition to a new starter, solenoid, and battery - which were all collateral damage due to the coolant pipe leaks.
I did confirm duplicate part numbers/labor for the warranty repair AND this repair.
Punchline: $5,000.00+ repair. Not a typo.
My vehicle just had its 100k tuneup. It had a coolant leak before it went in to be serviced. It got a new water pump, tensioner and pulleys. The repair shop also replaced a leaking coolant hose. After driving it it, the car still has a coolant leak. It appears to be coming from the thermostate housing under the front of the intake manifold. Not a happy camper.
Leak in thermostat housing. Am still trying to find best deal on repair.
I understand that engine must be removed and replaced at same time.
118,000 miles, bought recently, no service records.