The 6.2L EcoTec engine was released in 2014 to power GM’s performance vehicles and as the highest tier engine option for Silverado and Sierra trucks. Powering some of the most expensive GM vehicles, reliability is a big factor.
Unfortunately, the 6.2L EcoTec3 is prone to a number of common and serious problems such as lifter failure and bent pushrods due to active fuel management. It also suffers from some less serious problems like carbon build-up, fuel pump and injector failure, intake manifold gaskets, and a few transmission related issues.
While the 6.2 V8 engine isn’t unreliable, there are certainly some major problems to be aware of. This guide is going to discuss overall engine reliability, each common problem in depth, and provide a breakdown of each version of the engine so you can be aware what problem affects what version.
6 Engine Variations
- 2014-2019 Corvette C7 (455hp and 460tq)
- 2016-Present Camaro SS (455hp and 460tq)
- LT2: successor to the LT1 and designed specifically for mid-engine placement on the new Corvette’s
- 2020-Present Corvette Stingray (490hp, 465tq)
- L86 & L87: version of the LT1 slightly modified for use in trucks. 420hp and 460tq
- 2014-2018 Siliverado and Sierra
- 2014-2018 Yukon and Escalade
- 2014-Present Suburban and Yukon XL
- L8T: 401hp and 464tq
- 2020-Present Silverado HD and Sierra HD
- 2021-Present Express and Savana vans
- LT4: features 1.7L Eaton Supercharger
- 2015-2019 Corvette Z06 (650hp, 650tq)
- 2016-2019 Cadillac CTS-V (640hp, 630tq)
- 2017-Present Camaro ZL1 (650hp, 650tq)
- LT5: features 2.6L Eaton Supercharger
- 2019 Corvette ZR1 (755hp, 715tq)
6.2L EcoTec3 Engine Problems
- Carbon build-up
- Lifter collapse / bent push rods
- A8 Transmission shuddering or vibrating
- Other smaller / less common issues
- Fuel injectors / fuel pumps
- Engine mounts
- Manifold bolts
- Lower intake manifold gasket
1. Carbon Build-up
Unlike the predecessor Vortec engines, the new EcoTec3 engines use direct fuel injection instead of port-injection. On direct injection vehicles, the fuel is sprayed directly into the engine cylinders, completely bypassing the intake ports. Because there is no highly pressurized fuel going through the intake ports, there is nothing preventing them from getting gunked up.
As the gunk fills the intake ports, the volume of air that those ports can hold decreases. Ultimately, the engine can end up not getting enough air as necessary for it to function optimally.
Symptoms of Carbon Build-up
- Poor idling
- Slight performance & acceleration decrease
- Engine misfires
- Rich air to fuel ratios (will probably only be slightly rich)
Carbon build-up is going to naturally start to occur on day 1 of vehicle ownership. It usually won’t become noticeable or cause any performance implications until around the 80,000 mile mark, but this can depend on the type of gasoline and oil you are running.
The is one way to “prevent” this problem and one way to “fix” the problem if you are having performance issues. The prevention method is to install a catch can to capture the unused oil. The “fix” for the problem is to walnut blast your engine which shoots a bunch of highly pressurized walnuts through the intake ports to completely clean them out.
2. Lifter Collapse / Bent Push Rods
AFM deactivates four cylinders under certain driving conditions via a system of complex lifters, to improve fuel efficiency. These lifters are prone to collapsing due to oiling issues caused by AFM which can then lead to bent push rods.
If the lifters collapse or the push rods bend, the cylinder will not be able to open and close properly, leading to various performance and driveability related issues. While these issues are almost a guarantee on these 6.2L engines, they are covered under warranty.
The best bet to prevent serious repairs from bent rods or lifters is to disable AFM.
3. A8 Transmission Shuddering & Vibration
The A8 8-speed transmissions have been known to be problematic on both trucks and even the sports cars like the Corvette with this transmission. Most drivers will notice a vibration while driving, will feel the transmission shuddering or jerking during shifts, and will overall have noticeable poor driveability due to the transmission shifts.
The rough shifts are usually most noticeable from first to second gear and then from second down to first. The problem became so common among A8 transmissions that a class action lawsuit was filed. Since then, Chevy has posted TSB 18-NA-355 relating to the issues and the fix. Chevy claims that the issue stems from the moisture content of the transmission fluid that was used from the factory. In most cases, a fluid flush and filter replacement will get the trick done. If this doesn’t solve the problem, the torque converter will need to be replaced.
While most problems in general tend to occur later on, this problem tends to occur within the first 20,000 miles of the transmissions life.
4. Other Smaller / Less Common Issues
There are a number of other issues I have heard of and seen around on these engines, but I haven’t heard about them enough to classify them as common. So I’m going to cop-out and list them here as less common but prevalent issues. These include:
Fuel Injectors & Fuel Pumps
These are direct injection related problems. The fuel pump is responsible for delivering highly pressurized fuel to the fuel injectors. The injectors then spray the fuel into the cylinders. The fuel is usually sprayed at approx. 1,500psi of pressure, which is extremely pressurized. Because of the high pressure nature, the fuel pump and injectors are heavily stressed parts.
When the fuel pump fails, it can no longer adequately deliver fuel to the injectors. When the injectors fail, they can fail completely open or stuck closed which can cause serious fueling problems. The end result will be extremely poor engine performance, misfires, jumpy acceleration, engine noise, etc.
The engine mounts are known to go bad more frequently than engine mounts should. The constant 4WD puts a lot of pressure on the drivetrain and this results in the mounts wearing down a bit more frequently. I’ve read about people saying this is more prevalent on the driver side mounts, but have also seen it happen to the passenger side.
Bad motor mounts will cause a lot of rattle and vibration from the engine. It will usually get more noticeable as RPM’s increase.
Common on the Vortec 5.3 and 6.0 engines as well, the exhaust manifold bolts are known to break off. Broken manifold bolts will create an exhaust leak which will make the exhaust sound noticeably louder. If the leak is large enough, you will get a check engine light, probably some extra vibrations, and slightly worse fuel economy.
Intake Manifold Gaskets
The lower intake manifold gaskets are known to go bad which can create air leaks or vacuum leaks in the intake system. This can cause poor idling, sluggish acceleration, and overall decreased performance.
Chevy EcoTec3 6.2L Reliability
On a scale of 1 to 5, I’m going to put the 6.2L reliability at a 3. Lifter failure is extremely prevalent on these vehicles, despite engine age, and the transmission issues have also proven to be extremely common as well. While both of these issues usually occur earlier in the engines life and covered by warranty, the prevalence of the issues hurts my reliability score. Additionally, AFM continues to be an issue despite having been around for some time now.
However, outside of these few common issues, these engines have proven to be strong and capable. However, Chevy chose to not include the 6.2’s as an option on the HD 2500/3500 trucks because they do not expect it to be able to live up to the duty cycle required for their HD series work trucks, which are used more commercially. While this isn’t necessarily a negative, it just tells me that these engines were not meant to be workhorses and should not be used if you’re primary purpose of getting a truck is frequently towing heavy things.
These engines aren’t unreliable by any means. I believe the engine itself, the block, internals, etc. and the transmissions (with the fluid/torque converter problem fixed) are capable and have proven to be capable of lasting to 250,000 miles and beyond.