The cylinder heads have valves that are out of spec with 23,000 miles. the car is out of warranty due to age, and i was forced to purchase aftermarket cylinders heads to fix the worn valve issue to insure i don't drop a valve and have a catastrophic engine failure.
Z06 7.0l engine valve guides out of spec after 12k miles. this is due to a manufacturer defect in machining and or materials. failure of the guides results in dropping a valve and catastrophic engine damage. as a catastrophic failure often causes the rear wheels to lock and/or the engine to oil down the road and possibly the rear tires which could lead to an accident or injury to others. this is an extreme safety concern.
Excessive valve train noise, engine noise, knocking.
Tl* the contact owns a 2006 chevrolet corvette. while driving at any speed, the engine shook and the harmonic balancer wobbled. the failure recurred several times. the vehicle was taken to the dealer where it was diagnosed that the harmonic balancer needed to be repaired. the vehicle was not repaired. the manufacturer was notified of the failure. the failure mileage was 6,100.
Any quick search of the web will show that this car engine, the ls2 or 6.2 l engine has had a defect that gm has denied over the years and fails to stand behind after warranty; crank shaft pulley wobble and worn rubber gaskets on the harmonic balancer of the 2006 model year. tech bulletins have been issued and this topic of pulley wobble and rubber gasket failure and is quite the talk on various corvette forums. since i am well behind warranty, i had to have this diagnosed through my licensed certified auto mechanic. this repair requires extensive labor time to repair. scared to see the bill tomorrow. gm's response is i should of taken it to an authorized chevy dealer. that is hog wash because should i had done that, i would probably still had to pay their exorbitant labor costs and still not be covered on this serious engine defect. in fact, i believe gm has re-designed the part so what does that tell you. failure to fix will just harm the engine for the future and replace belt after belt when the true problem is ignored by gm
I started the car when it was cold, it began to squeal from the belts. i gave it a small rev and it squealed intensely, i mean very loudly! i opened the hood and belts were not moving. i could not move the car. the harmonic balancer had lost it's bond. i am just glad i was sitting still. at speed, the steering would have been lost, it could have killed me! i had the car towed to the shop, and it cost me $1000.00. not good! i read that this happens alot. bad design for sure. i should be reimbursed. what can i do? chevy won't even talk to me about it. it's a shame because i love my car, but now i am afraid to drive it! *tr
The harmonic damper on 2006 corvette with ls2 engine failed resulting in power steering drive belt coming off pulley causing loss of power steering. the high effort required to steer vehicle almost resulted in crash. this harmonic damper issue is documented in numerous internet forums and is believed to be a widespread issue that should be recalled and corrected by the manufacturer. *js
I was concerned about excessive valve train noise and after reading several accounts of improperly machined heads by gm's supplier linamar, and that numerous vehicles have had valves drop, resulting in engine failure. as a result, after having been rebuffed by chevrolet, i took my car with 36,000 miles on it to a corvette specialty shop to have my valve guide clearance tested. i had several exhaust valve guides outside the maximum service specifications, indicating that a catastrophic engine failure was imminent. the car was repaired with proper re-machining of the heads to make the valve guides concentric, new intake and exhaust valve guides installed, as well as new seals, valves, springs, etc. 88% of the corvette forum members who have had their cylinder heads tested for excessive valve guide wear, were out of service specifications. source: http://www.corvetteforum.com/forums/...-registry.html 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 loss of steering, braking capability, and which can result 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 while the vehicle is underway on public roadways. *tr
Ls7 engine makes loud "ticking" sound at idle to ~ 2,000 rpm caused by defective cylinder heads which were improperly machined by gm's subcontractor. local chevrolet dealers said the noise is "normal"... but when heads opened and valve and valve guides measured, excessive valve and valve guide wear documented. local gm dealer & $4,350 gm protection plan (extended warranty that i had to buy to cover this $5,000 repair) refused to repair so i had to drive it 5 hours to another gm dealer to get it repaired under my gmpp extended warranty. many other 2006 to 2015 corvette owners have experienced this same excessive valve wear including some owners valves breaking and destroying their $16,000 ls7 motors while spewing oil and metal everywhere. this also resulted in a fear of driving this car, a significant "diminishment of value" of this vehicle, and complicated its resale (buyers had heard about these catastrophic ls7 motor failures.
According to corvette forum, this is another widespread problem- the harmonic-balancer becomes warped and requires replacement... if not done timely, other "parts" could be negatively impacted as well... *tr
Started hearing squealing sounds a few weeks ago. noticed the crankshaft pulley had a noticeable wobble. did a google search & found multiple reports on forums, youtube and such of of others with the same problem. also my friend with the same car but a newer year just had it replaced under warranty. my car is off warranty but a harmonic balancer should not wear out in six years with just 7,500 miles (yes, seven thousand five hundred). my 2000 ford expedition has 151k. chevrolet wants about $1,000 to replace it. *tr *js
The exhaust valve broke and destroyed the motor