Sudden power loss

cosmicdust73

I have what sounds like the exact same power loss on a 2013 370z Touring AT. The problem only turns up during temperature extremes... either very cold <15F or very hot >95F. The issue is always resolved by shutting off the car and starting it back up. Sometimes it takes 2 or 3 restarts for the problem to go away. Symptoms include 1-2 second throttle delay as well as dramatic loss of horsepower. The most significant HP dropoff is in 3rd gear. When in full automatic mode (i.e. Drive), the car refuses to downshift on its own. I can floor the pedal and only sometimes will it aggressively downshift with extremely high revs... but the car hardly accelerates. No error codes are thrown at all... so the issue is impossible to reproduce or be fixed by the dealer. As it stands, I need to wait for the problem to re-occur again and then take it directly to the dealer without shutting it off. The problem does not resolve itself without shutting off the vehicle and restarting. Very dangerous problem because if it happens suddenly in the fast lane, it can be very difficult to get out of the way of the car behind you!