I own a 2003 Volkswagen Passat Wagon 2.8L SFI DOHC 6cyl. I have a code P3081 I have replaced the temp sensor and the reserve coolant tank I am going for the thermostat next. I cannot get rid of this code any ideas? Also since the code started when my wife drive short distances and turns off the car it wont start again for about 15 min unless it is jumped started. To top it all off she came home yesterday and said she turned on the a/c and it worked for about 10 min and then made a lot of noise and quit working. Any help or suggestions are much appreciated and sought after.
You need to get at the root cause of the code, replacing the sensor didn’t change what the sensor is sensing. What does the coolant reserve tank have to do with anything? It is just an overflow tank. Unlikely the thermostat is bad.
You might have a blown head gasket. I suggest a good independent VW knowledgeable mechanic needs to evaluate your car and diagnose the real problem. Don’t throw more parts at it until you know what is going on.