NHTSA Complaint #11415700 — 2014 INFINITI Q50

ENGINE HAS ROUGH IDLE WHILE IN PARK. EVEN AFTER THE FOLLOWING MAINTENANCE WAS DONE. REPLACING SPARK PLUGS, ENGINE SOFTWARE UPDATE, COOLANT FLUSH, POWER STEERING FLUSH, FUEL SYSTEM CLEAN, NEW MASS AIR FLOW SENSORS BOTH SIDES, SERPENTINE BELT, ALL NEW GASKETS ON TOP PART OF ENGINE, VALVE COVER, INTAKE MANIFOLD, SPARK PLUG TUBE SEALS. FLUSHED REAR AND REAR DIFF AND TRANSMISSION. STEERING IS HEAVY TO TURN. THE COLDER IT IS OUTSIDE THE WORSE THE ENGINE SHAKES. THROTTLE RESPONSE IS DELAYED AT TIMES. TRANSMISSION SHIFTS HARD THE WORSE THE ENGINE SHAKES. COLDER IT IS THE SLOWER THE WINDOWS ROLL UP AND DOWN ALONG WITH THE WIPERS. ENGINE DROPS RPM WHEN TURNING WHEEL WHILE IN PARK. WHEN DRIVING ENGINE DROPS ABOUT 100 - 200 RPM THEN KEEPS GOING BACK UP UNDER ACCELERATION BUT CAUSES TRANSMISSION TO SHIFT HARD. THIS PROBLEM CAUSES THE OUTPUT SHAFT SEAL TO BREAK AND REAR WHEEL SPEED SENSORS WERE REPLACED. AFTER A SHARP TURN CAR HESITATES TO ACCELERATE EVEN IF HARD ON THE GAS. EXTREME COLD TEMPS OUTSIDE MAKE THE ENGINE ALMOST SOUND AS IF SOMETHING INSIDE ENGINE INTERNALS IS NOT RIGHT. HOT AND HUMID WEATHER MAKES IT RUN THE BEST. NO CHECK ENGINE LIGHT PROBLEM STARTED AT 90,000 MILES NOW IM AT 126,000 MILES AND STILL NO FIX AND NO CHECK ENGINE LIGHT. LOSS OF ENGINE POWER. EVEN GOING UP THE SMALLEST HILL INCLINE MAYBE A COUPLE FEET OVER A DISTANCE OF MAYBE 3 BLOCKS ENGINE DOWNSHIFTS TO 5TH GEAR JUST TO MAINTAIN 70MPH EVEN THOUGH I CAN BE GOING 50MPH IN 7TH GEAR. CAR JOLTS FORWARD WHEN COMING TO A STOP AS IF THE OUTPUT SHAFT IS STILL SPINNING AT A DIFFERENT SPEED THAN THE ENGINE. CAN CAUSE AN ACCIDENT IF NOT FIXED. OTHER INFINITI CARS SEEM TO HAVE THE SAME PROBLEM. EVEN THE G37.