The Chevy LT2 Engine Issues. The 2020 C8 Corvette features GM’s LT2 engine. It has a 6.2L naturally aspirated V8 engine with 495hp and 470lb-ft of torque. The C8 Corvette was the first mid-engine Corvette built.
The LT2 is a member of General Motors Gen V small-block V8 engine family. It is the successor to the LT1 engine used in the C7 Corvette and Cadillac CTS-V, not the earlier generation LT1 engines that were 5.7L V8s. The LT2 was based on its predecessor and shares many similarities, including the compression ratio, block, heads, crank, and pistons. It also has the same bore and stroke. Direct injection is used for fueling. The LT2 also employs active fuel management and variable valve timing.
While the LT2 has only been on the market for a short time, a number of issues have arisen. We’re not going to call any of these issues “common” just yet because we believe they’ve been over-hyped on the internet. However, we thought it was important to outline the issues encountered thus far.
Chevy LT2 Engine Issues
Some of the most common Chevy LT2 issues are:
- Valve springs that have broken
- Transmission issues
- Hydrocarbon pads that have been broken
- No-start cranking or prolonged cranking
It’s worth repeating that the majority of these LT2 issues are exaggerated on the internet. Having said that, supply chain issues did result in some manufacturing defects with various components of these engines, the majority of which were caused by bad manufacturing batches. Aside from the issues mentioned above, we’ve received complaints about the navigation unit, peeling dashboards, wheels, brakes, and a variety of other minor electronic components.
So far, there have been a few catastrophic engine failures. While this has some people concerned because not many C8s have been produced yet, we believe the number of complete failures in relation to the amount produced is not alarming.
Because of the similarities with the LT1, this isn’t a completely new engine, but it is a new engine. Random problems are unavoidable in first-year engines and automobiles. Fortunately, Chevy and GM have been very helpful so far in resolving all of these issues under warranty for no cost.
1. LT2 Broken Valve Springs Problems
Corvette C8 LT2 engines built between June 1st and September 15th, 2020, had a bad batch of valve springs. This problem also affected a number of other engines, including the LT1, LT4, and others. This was purely a manufacturing flaw, and no engines built after those dates are affected. GM issues a service bulletin requiring the installation of new valve springs as well as a cylinder leakdown test. If the cylinders leak, the engine will be disassembled and repaired or replaced as needed.
When the valves are closed, valve springs are responsible for keeping them sealed. The valve opens as the pushrods move up and the rocker arms move down, compressing the valve springs. The valve spring provides the necessary pressure to close the valve and keep it completely sealed when the camshaft rotates and the valves need to close.
When a valve spring fails, the valve does not open or close properly, causing the cylinder to lose compression. Misfires, an engine ticking noise, and some trouble codes are the most common symptoms on the C8 Corvette.
Related : The Four Common Hyundai 1.6 Engine Issues
Symptoms of a Broken Valve Spring in an LT2 Corvette
- Misfires in the cylinders
- Cylinder compression loss
- P0300, P0106, and P0506 are engine codes.
- Lifter tick-tock noise
As previously stated, this issue is limited to a specific set of C8s. Chevy will repair any problems under full warranty.
2. Transmission Issues with the C8 Corvette
The C8 Corvette was not available with a manual transmission. It was instead only available with an 8-speed dual clutch transmission (DCT). While owners with good transmissions have praised its smoothness, many others have reported transmission problems. This appears to be the most common of all the issues on our list.
Tremec’s TR-9080 DCT transmission has had its fair share of shifting complaints. Owners report issues with downshifting, frequent hard shifts, shuttering or bucking, and so on. Furthermore, when stopped, it has difficulty shifting into first gear and is especially rough from third to second and second to first.
These transmission problems have been accompanied by the following engine codes: P2724, P0867, P0868, and P0869.
While the cause of these issues is unknown, changing the DCT fluid has helped some people. However, where a simple fluid flush hasn’t worked, GM has been replacing the transmission entirely. Rather than repairing transmissions, GM has decided to replace every problematic transmission.
3. LT2 Hydrocarbon Broken Pads
Two hydrocarbon pads sit directly outside the intake duct on the LT2 intake airbox. Their function is to absorb any exhaust fumes that exit the engine via the intake system. These pads were first introduced in the C6 Corvette and have been a source of contention in every Corvette since.
Adhesive is used to seal the pads to the intake housing. This adhesive deteriorates quickly, causing the carbon pad to be partially sucked into the air duct. When this happens, airflow to the cylinders is restricted, which can confuse the MAF sensor and air-to-fuel ratios, cause misfires, and set off a variety of engine codes.
There is no problem because the pads are too large to be completely sucked into the intake system. The only issue is the obstruction of airflow to the cylinders and the problems that this causes. Fortunately, removing the pads and opening the intake box is all that is required to resolve this issue. Because removing the pads causes no engine problems or concerns, we recommend doing so anyway.
Symptoms of Carbon Pad Blockage
The following are symptoms of GM LT2 carbon pad issues:
- Incorrect MAF sensor reading (P0101)
- The engine is running lean (P0171, P0174)
- Misfires in the cylinders
- Idling in a rough manner
- P1101, P0300, P2119, P2101, P219A, and P219B are some other engine codes.
To resolve this issue, simply remove the pads. Because they are likely to pop off at some point, doing this ahead of time isn’t a bad idea.
4. LT2 C8 Crank Not Starting Issues
A common issue with all GM engines equipped with the K20 ECM is a cranking but no start condition. This problem occurs when the car continues to crank but does not start. People have reported that it will crank for up to a minute without firing up. This problem is also known to cause long cranks, in which the car will start but only after 10+ seconds of cranking.
Problems with the K20 ECM cause the extended crank or crank no start issue. Chevy and GM issued a technical service bulletin, blaming the problem on internal ECM issues. This problem has been resolved by simply reprogramming the ECM, though in some cases the ECM must be completely replaced.
The P12A6 engine code is the most obvious indicator of this issue.
Reliability of the Chevy LT2 C8 Corvette
Is the C8 Corvette trustworthy? Yes. Does it have any first-year issues? Yes. Overall, we have no reservations about the LT2 engine found in the new C8 Corvettes. It has had its fair share of issues thus far, but the majority of them are minor in nature.
Broken valve springs were a one-time occurrence that has since been resolved. While transmission problems appear to be more common, they are still uncommon, and Chevy is providing free repairs. Carbon pads falling off is a minor and insignificant occurrence, but it is common. Finally, the crank no start problem can be resolved with a simple ECM update.
The internet has mostly exaggerated the reliability and LT2 engine problems due to a few catastrophic engine failures that occurred with only a few thousand miles on the engines. We’ve seen bent rods on a twin-turbo setup that’s been all over the internet, but there are still C8s out there making serious power with stock rods in twin setups.
This is a new engine installed in a new chassis. It is the first mid-engine Corvette built. So, yes, first-year models will have their fair share of minor issues and a limited number of major issues. The good news is that GM has been very accommodating to new owners who have issues so far.
We expect a number of these issues to be resolved in the near future and have no concerns about the LT2 engine’s long-term reliability.
