Porsche Tech Notice:
Not a frequent issue, but one that has the potential for misdiagnosis. Typically the indicators are a low temperature display, or the display only works sporadically. When a technician checks the fault codes in the DME control unit, the fault codes are P2181 (thermostat stuck open) and P3081 (engine coolant temperature implausible). These issues can occur independently of each other, or at the same time - depending on driving style and geograhic region.
The main cause is a blocked valve, see the first photo. Another idication of a defective disc valve is when the oil temperature and coolant temperature are almost identical in the warm-up phase. As a rule, the coolant temperature should be higher than the oil temperature.
Deformation of the sealing ring (photo 2) can mean that the disc valve can no longer be guaranteed. As a result, an additional cooling circuit is opened via transmission cooling in the warm-up phase and the engine is slow to reach operating temperature. Photo 2 shows the cut-away view of the valve, and the arrow is pointing at the correct position of the sealing ring.
If the symptoms above are verified by an authorized technician, a visual inspection and function test of the valves are recommended before replacing.
Always consult an authorized Porsche technician for diagnosing any problems, especially if your car is under the factory warranty.
For 2007-12 GT3 & GT3 RS models.