It was exactly one month ago that GM issued a service bulletin regarding a batch of bad valve springs that were used across the GM V8 line-up that includes the 2020 Corvette’s LT2 engine. Drivers may experience engine misfiring and a check engine light when one of the valve springs fails.
In that original TSB, General Motors stated the faulty valve springs were used in the production of the engines from June 1st – September 15th. However, more and more Corvette owners whose engine build dates were past September 15th were also experiencing broken valve springs.
Because these customers were outside the production window of the TSB, they not covered by the full fix which was to replace all the valve springs. Instead, only the broken spring was replaced. As some of the drivers were on road trips, you can imagine being somewhat fearful that one of the other springs will also break while on the road.
Fortunately, GM has updated the techlink article and has expanded the window to include these latest cases. The new end date for affected 6.2L engines is now October 7th, 2020.
Now for some bad news.
Because the fix requires all valve springs to be replaced on the 6.2L engines, you can imagine the demand this has put on sourcing replacements as 16 new springs are required for each affected engine. Owners all needing replacements in addition to the C8 Corvette include those who own the Chevy Silverado and GMC Sierra pick-ups, as well as Camaros with the LT1 and LT4s. Some of those with the issue report their dealerships warning them of extended waits as everyone scrambles to find the replacement springs.
Also keep in mind that the new end date references the build date of the LT2 engine and not the production date of the car, which generally happens weeks after the engine has been constructed at the Tonawanda engine plant in New York and then shipped to Bowling Green, KY for installation. So affected Corvette engines with the bad valve springs could around longer than originally expected.
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