2008 Chevrolet Corvette Z06

CAR HAS 20,000 MILES AND HAS DEVELOPED A GAS SMELL WHILE PARKED IN A GARAGE. IT SEEMS TO BE FROM THE RIGHT REAR OF THE CAR. WHEN THE SYSTEM IS BELOW 1/2 FULL THE SMELL IS LESS APPARENT.. THERE IS NO VISIBLE LEAK IN THE FUEL TANK AREA. I HAVE REPLACED THE CROSS OVER PIPE SEALS AND FUEL PUMP "O" RINGS. PROBLEM IS STILL PRESENT. WAS NOT AWARE OF HISTORY OF POSSIBLE DEFECTIVE PLASTIC ON THE FUEL PUMP FITTINGS. I WILL RUN TANK BELOW 1/2 TO SEE IF SMELL GOES AWAY. WILL MOST LIKELY REMOVE AGAIN OR ADDRESS WITH MY EXTENDED WARRANTY AS WITH MORE RESEARCH THIS SEEMS TO BE A QUITE COMMON PROBLEM AND POTENTIALLY SERIOUS. I MUST LET CAR SIT OUTSIDE FOR AWHILE AND ALLOW FUEL FUMES TO DIMINISH BEFORE I FEEL COMFORTABLE PUTTING CAR IN GARAGE. THIS SMELL CAN BE VERY HEAVY WHEN LEFT IN A CLOSED AREA RIGHT AFTER DRIVING. I CAN STILL SMELL FUEL FUMES WHILE DRIVING.

HAD TO HAVE THE HEADS REWORKED BECAUSE OF BAD GUIDES AT 13,500 MILES. CAR OUT OF WARRANTY GM DOES NOTHING AND CLAIMS THERE ISN'T A PROBLEM. STOCK 2008 Z06 WITH 13,500 MILES ALL (8) EXHAUST OUT OF SPEC, (3) INTAKE OUT OF SPEC (5) INTAKE ONLY IN SPEC BY .0001-.0004 MEASUREMENT DONE BY KATECH/WCCH CAN PROVIDE DATA IF NEEDED

I HAD TO REPLACE THE EXHAUST VALVES IN MY 2008 Z06 IN ORDER TO PREVENT CATASTROPHIC FAILURE. REPLACED 2-PIECE SODA FILLED VALVES WITH 1 PIECE STAINLESS STEEL VALVES. UPON INSPECTION VALVE GUIDES ON #3 HAD EXCESS SLOP. SENT HEADS OUT FOR MACHINING AND NEW GUIDES. STOCK ENGINE HAD LESS THAN 20K MILES. MANUFACTURER OF ENGINE HAS ISSUED SERVICE BULLETINS ACKNOWLEDGING THESE ERRORS EXIST.

THE LS7 ENGINE HAS A DEFECT THAT CAUSES ACCELERATED VALVE GUIDE WEAR. CONTINUING TO DRIVE THE CAR WILL EVENTUALLY LEAD TO A VALVE DROPPING AND CAUSING CATASTROPHIC ENGINE FAILURE. ONCE THIS OCCURS THERE WILL BE A LOSS OF POWER STEERING, POWER BRAKES, AND WATER/OIL COULD GET ON THE TIRES LEADING TO A LOSS OF CONTROL OF THE CAR. IN A FEW CASES FIRE HAS ERUPTED. HERE ARE TWO VIDEOS OF THE ISSUE HAPPENING: HTTPS://WWW.YOUTUBE.COM/WATCH?V=TM4MDCIX-KI HTTPS://WWW.YOUTUBE.COM/WATCH?V=ZLT7DJNKVNY LUCKILY I FOUND THE EXCESSIVE VALVE GUIDE WEAR BEFORE THE ENGINE FAILED, BUT IT COST ME $3000 TO HAVE THE HEADS REBUILT. UPDATED 09/15/15*LJ *CN

I WAS CONCERNED ABOUT EXCESSIVE VALVE TRAIN NOISE AND AFTER READING SEVERAL CORVETTE FORUM THREADS ABOUT IMPROPERLY MACHINED HEADS BY GM'S SUPPLIER LINAMAR, AND THAT NUMEROUS VEHICLES HAVE HAD VALVES DROP AND RUIN THE ENGINES, I TOOK MY CAR WITH 40000 MILES ON IT TO A CHEVROLET DEALER TO HAVE MY VALVE GUIDE CLEARANCE TESTED. I HAD INTAKE VALVE GUIDES OUTSIDE OF SERVICE SPECIFICATIONS, EXHAUST VALVE GUIDES OUTSIDE OF SERVICE SPECIFICATIONS, AND A COMBINATION OF OTHER INTAKE AND EXHAUST VALVE GUIDES AT OR NEAR THE MAXIMUM OUTSIDE OF SERVICE SPECIFICATIONS. THE CAR IS BEING REPAIRED WITH NEW HEADS AND GUIDES. GM NEEDS TO ISSUE A RECALL ON THIS ISSUE, THERE HAVE BEEN NUMEROUS ENGINE FAILURES AS A RESULT OF A DROPPED VALVE INTO A CYLINDER WHICH CAN CAUSE ACCIDENTS AND FIRES. GM IS VERY AWARE OF THIS ISSUE, BUT REFUSES TO DO ANYTHING ABOUT THIS HUGE SAFETY RISK TO DRIVERS, PASSENGERS, AND NEARBY VEHICLES IF THE ENGINE FAILS GOING DOWN THE ROAD. *TR

DURING MODERATE ACCELERATION AND MID RANGE RPMS, THE ENGINE CATASTROPHICALLY FAILED ON THE HIGHWAY. A HOLE WAS BLOWN IN THE ENGINE BLOCK AND THE CAR SPEWED SMOKE, OIL AND CHUNKS OF METAL FROM THE ENGINE ALL OVER THE ROAD AS I VEERED OFF ONTO THE SHOULDER. THE SUSPECTED ISSUE WAS FAULTY HEADS AND IMPROPERLY MACHINED VALUE GUIDES. THIS ENGINE WAS REPLACED UNDER WARRANTY. THE SECOND ENGINE HAD AN ISSUE WITH THE CLEARANCE BETWEEN THE CRANKSHAFT AND THE PISTON ARM. AFTER APPROXIMATELY 4500 MILES ON THE SECOND ENGINE, THE CAR LOCKED UP AND DIED IN THE MIDDLE OF TRAFFIC CAUSING A MASSIVE TRAFFIC JAM FOR ABOUT HALF AN HOUR. I HAD TO PUSH THE CAR BY HAND IN TRAFFIC TO THE FARTHEST EDGE OF THE RIGHT HAND LANE SINCE THERE WAS NO SHOULDER. AFTER THE CAR COOLED DOWN FOR HALF AN HOUR I WAS ABLE START THE VEHICLE AND MAKE IT TO A DEALER. THIS ENGINE WAS ALSO REPLACED UNDER WARRANTY. *JS