2010 TOYOTA SEQUOIA Engine Problems

A VALVE SPRING BROKE WHILE TRAVELING ON THE HIGHWAY, CAUSING THE VEHICLE TO SHUDDER AND REQUIRE A SLOWER SPEED. I FORTUNATELY WAS NOT IN HEAVY TRAFFIC BUT HAD CIRCUMSTANCES BEEN DIFFERENT THIS COULD HAVE POSED A MORE SEVERE SAFETY ISSUE. UPON RESEARCHING THIS PROBLEM, I'M FINDING INCREASINGLY MORE INSTANCES WHERE THE SAME ISSUE HAS HAPPENED TO OTHER TOYOTA OWNERS WITH THE SAME ENGINE. ALL AROUND THE SAME MILEAGE (117K).

WHILE TOWING 6000 LB TRAVEL TRAILER HEAT EXITING THE EXHAUST HAS MELTED REAR BUMPER COVER NEAR EXHAUST TIP. EVERYTHING ON VEHICLE IS FACTORY ORIGINAL AND SHOULD NOT BE MELTING FROM EXCESS HEAT GENERATED BY TOWING WITHIN FACTORY SPECIFIED WEIGHT LIMITS. POSES A FIRE RISK.

I HAVE AN AMMONIA SMELL, WORSE THAN A ROTTEN EGG, UNDER HARD ACCELERATION, THAT COMES THROUGH THE VEHICLE VENTS AND INTO THE CABIN, EVEN WITH ALL WINDOWS UP AND VENTS ON RECIRCULATION OR OUTSIDE AIR. MANY SEQUOIA OWNERS HAVE REPORTED THIS TO TOYOTA, AND THEY HAVE NO KNOWN FIX. THE ODOR THAT COMES INTO THE CABIN BURNS YOUR EYES FOR A FEW SECONDS, AS WELL AS MAKES MY PASSENGERS AND I NAUSEOUS, AND DISTRACTS ME WHEN I'M DRIVING. I BELIEVE THIS IS A SAFETY HAZARD, BECAUSE WE ARE INHALING WHATEVER IS IN THE CABIN, AND I CAN IMAGINE THAT IT IS NOT SAFE, LIKE ANY EXHAUST.