AT 80K MILES, THE 3.5L INFINITY/350Z MOTOR THAT HAS BEEN *VERY* WELL TAKEN CARE OF HAD A KNOWN ISSUE OCCUR WHICH CAUSED THE VALVE TO COME LOOSE IN THE ENGINE. THERE IS A PROBLEM WHERE SOME SCREWS WHICH HOLD A BUTTERFLY VALVE TOGETHER WIGGLE LOOSE AND IS INGESTED INTO THE ENGINE. THIS CAUSES THE VALVE TO GET DAMAGED AND FALL OUT RESULTING IN TOTAL ENGINE FAILURE. NISSAN KNOWS THIS OCCURS AND IS UNWILLING TO HELP ME WITH THE REPAIR. WHEN THIS OCCURRED TO ME, I WAS IN A VERY BAD SITUATION AND NEARLY LOST CONTROL OF THE CAR, I WAS LUCKY ENOUGH TO GAIN CONTROL AGAIN HOWEVER THERE WAS SOME DAMAGE TO THE CAR WHEN I NEARLY WENT INTO THE DITCH. I HAVE A POLICE REPORT AS WELL. SO NISSAN KNOWS THEIR TOP OF THE LINE ENGINES CAN WITH NO WARNING FAIL WHICH AT ANY SPEED CAN BE A POTENTIAL SERIOUS ACCIDENT. THE FIX IS SIMPLE TO PREVENT IT, SECURE THOSE SCREWS WITH SOME GLUE OR LOCK TIGHT, BUT IF THEY ADMIT THIS IS A DESIGN FLAW, THEN THEY'D BE RESPONSIBLE FOR THE DAMAGED ENGINES AND THEY SEEM TO PREFER TO DENY IT. I JUST SPENT A WEEK TRYING TO GET THEM TO TAKE SOME RESPONSIBILITY AND THEY WONT. THIS IS BEYOND A WARRANTY ISSUE IN MY OPINION IF IT CAN CAUSE THE DRIVER TO LOOSE POWER AND LOOSE CONTROL OF THE CAR. IT HAPPENS QUICKLY AND THE IMPACT ON CONTROL IS IMMEDIATE. NOT SAFE AT ANY SPEED. SO THIS COMPLAINT IS ONE OF SAFETY AND ONE OF HAVING TO COVER A TOTAL ENGINE FAILURE NO MATTER HOW WELL YOU TAKE CAR OF YOUR ENGINE. *TR