Best and worst Corvette C6 years — which to avoid

The C6 generation of the Corvette makes a great pick among the more recent models, but only if you avoid some troublesome years. Of course, going through common problems that the C6 had as a model can often be misleading, so buying a reliable model requires knowing exactly which Corvette C6 years to avoid.

To figure that out, our team used various prominent sources of information to rank the C6 years from most reliable to least reliable. Going through NHTSA reports and details on C6 complaints helped us get the bigger picture of the best years to buy and worst Corvette C6 years to avoid, and we’ll tell you all you need to know so you can make the smartest possible buying decision.

Why you can trust REREV’s advice on which car model years to avoid: Our car experts look at official data, ask real drivers what they think, and talk to experienced mechanics to make sure our list is useful. This reliable info can make buying a car easier for you. Want to know how we do it? Find out more about our research methodology.

How we rated the best and worst Corvette C6 years

As we crafted our guide on the best and worst Corvette C6 years, our experts focused on two main streams of information. First, we explored all of the complaint reports that former C6 owners have submitted to NHTSA, as well as recall logs issued by Chevy for particular C6 model years.

We also examined all the available reviews from trusted websites like Edmunds, KBB, and Consumer Reports, alongside some details that we’ve uncovered from Corvette C6 forums. Based on all of those, as well as common Chevy Corvette C6 problems through model years, we were able to pinpoint the best and worst ones:

Most common Corvette C6 problems

While the sixth generation of the Corvette proved to have good and even great model years in terms of reliability, there have also been some pretty bad ones. We made sure to include them on our list of Corvette C6 years to avoid, and going through their common issues was one of the main points we focused on.

1. Timing chain tensioner issues

Most vehicles have timing belts, but the Corvette C6 has a timing chain instead. Its main advantage over the more traditional timing belt is that it does not stretch with time and lasts longer.

However, the LS3-powered Corvette C6s are most prone to timing chain tensioner failure. When the tensioner fails, it damages the timing chain, and the reaction it sets off sometimes causes severe damage to the rest of the engine.

While replacing the timing chain and its components is not an inexpensive assignment, you can get some upgraded replacements. These upgrades are not prone to having the same issue the old timing chain tensioner had, making the fix somewhat permanent.

2. Rod bearing failure

Before 2012, Chevrolet used tri-metal rod bearings made of bronze, lead, and steel. They had to replace the tri-metal configuration with a bi-metal aluminum-and-steel one for the 2012 model. Though replacing the lead with aluminum was a good step health-wise, aluminum did not have the quality lead to guarantee engine longevity.

Unsurprisingly, the new rod bearings wore out rapidly. Some drivers were unfortunate enough not to notice the problem until it culminated in an excessive rod knock. Worn bearings are among the main rod knock symptoms, which may seriously affect engine operation.

One excellent way to arrest the situation on time is to use higher oil grades that can easily be analyzed to check the extent of the rod bearing wear before it causes problems for other parts of the C6. Alternatively, you could find aftermarket tri-metal bearings to replace the old one, so you do not have to worry about forgetting to do the oil test.

3. Wobbling harmonic balancers

The harmonic balancer is also called a crankshaft damper and has the sole purpose of protecting the crankshaft. It is a round metal disc with rubber infusions in its making that absorbs vibrations caused by the firing of the cylinders in the engine. In simpler terms, it is a crankshaft shock absorber.

When this specific shock absorber has been in operation long enough, the outer weighted ring often gives way to the amount of force it absorbs and starts falling slowly down the center mount quite close to the engine block. If you do not notice this problem on time, it will damage whatever stands in its way.

Many Corvette C6s have had issues with this component. Affected drivers have experienced a broken crankshaft, block, or oil pump whenever the component fails and is not noticed on time. If you are buying a Corvette C6 off the used market, you must inspect the engine for this issue so you can arrest it on time.

4. Valve guide issues

The severity of the problems the valve guide presented, especially with the C6 Z06’s engine, made drivers attempt to file a class-action lawsuit against Chevrolet for the dangers it posed.

The LS7 V8 engine had titanium intake valves and con rods which were part of the reason the Z06 could rev up to 7100 rpm. However, the valve guides wear down pretty quickly, starting a chain of problems in its wake.

Worn valve guides cause excess valvetrain noise, which only subtracts from the noise comfort of a ride. Over time, the broken valve guides deteriorate to the point where oil leaks into the combustion chamber, burns, spoils spark plugs, and causes misfires. In some situations, it can also cause catalytic converter damage.

The valves and engine could break if the issue is not arrested on time. Eventually, the cause of the problem was traced to faulty cylinder heads from one supplier.

5. Alternator issues

Alternator problems are generally a common issue for many old vehicles. It is not only caused by age but heat too. Sometimes, they might be entirely functional but fail to charge the battery properly.

Replacing the alternator on the Corvette C6 is pretty straightforward, as the alternator is easily accessible. If you do not have confidence in your abilities, it is best to have a professional handle the replacement. Most drivers don’t wish to waste time on this and wonder – how long does it take to replace an alternator? As you can see, it’s a relatively quick procedure and it’s always better to replace it and be safe than to worry about your battery being improperly charged.

6. Fuel tank problems

Some drivers of the Corvette C6 models of 2007 and onwards have complained about damaged or cracked fuel-sending units, fuel pumps, and fuel tanks. General Motors had to cover the issue in a technical bulletin to help guide drivers on how to repair the problem.

Worst Corvette C6 years to avoid

Without a doubt, the most serious C6 issues were engine problems and most affected drivers started experiencing problems after the 100,000-mile mark. Naturally, this raises a big question for potential buyers – what are the worst Corvette C6 years?

The worst Corvette C6 years are 2005 and 2008, but there are a couple more years that gave their owners headaches:

• 2005
• 2006
• 2007
• 2008

We’ll further discuss the issues that affected those model years to see what made them the worst possible options.

Corvette C6 (2005-2008 model years)

Corvette enthusiasts recommend avoiding the 2005 to 2007 Corvette C6s because of their many problems. Chevrolet has had multiple recalls to address some of the issues these model years exhibited, such as steering column issues, roof panel failure, and low-beam headlight wiring problems.

The 2005 C6 was the worst hit with problems and had the most complaints for a C6 model. Some drivers call it the worst year for the Corvette C6. For the 2008 model year, most of the engine issues were resolved, but a transmission problem appeared for versions equipped with an automatic gearbox. On top of that, a lot of drivers reported smelling a fuel odor within the driver’s cabin, usually due to gas tank cracks.

What are the best Corvette C6 years to buy?

Regardless of all the badly rated models, the C6 Vette is still considered one of the best options among enthusiasts. The ZR1 and Z06 versions are especially appreciated in the Corvette-loving community, and these are the best year iterations of those:

• 2009
• 2010
• 2011
• 2012

These models didn’t have that many issues with the engine, especially since the rod knock issue and cracked valves were settled for the previous few years. So, let’s take a look at a few of the best-rated models to give you a detailed comparison versus the worst ones.

2010 Corvette C6

The 2010 C6 Vette makes one of the absolute best picks simply due to its record of low complaint numbers. We’ve hardly found any issues with those, and all the engine options are seemingly fine in the long run as long as you maintain the car properly.

That being said, our team deemed the 2010 Corvette C6 as one of the priority picks for every interested buyer. With an impressive rating and positive driver feedback, this model served previous owners well except for a few light issues like electrical system faults.

2012 Corvette C6

Along with the 2010 model, the 2012 C6 Vette represents the finest that this generation has to offer. This time around, we have to say there were some more issues including A/C heater problems and airbag functionality, but those were pretty low in numbers.

A perfect reference to the overall reliability of the 2012 Corvette is the list of recalls which only contained a single action made by Chevy and that one was related to door latches and retention. Other than that, there were no logs of any engine or transmission-related problems, and that along with the brakes is precisely what you are paying for in this car.

Is the Corvette C6 worth buying?

The Corvette C6 is one of the best cars in the used market. The many improvements the vehicle underwent make it excellent for use even in recent times.

Aside from the incredible performance you would be getting at a low price, it would interest you to know that the C6 is a worthy investment. Soon, it is expected to become a rare vehicle as less of it is seen in the market. The Corvette C6 has held its value well and continues to be one car enthusiasts can’t get over.

If you’re curious about the Porsche 996 years to avoid, Corvette C4 years to avoid and Corvette C7 years to avoid, we’ve got the details. We looked at their best years and the ones that could have been better.