General Motors has issued a new service bulletin to address the valve spring issues some of its newer V8 engines are experiencing.
The service bulletin indicates that vehicles equipped with certain GM V8 engines may produce a service engine light along with a misfire and strange engine noise. The issues can be linked back to faulty valve springs, with the bulletin instructing the service department to check for a broken valve spring and, if necessary, perform a cylinder leakage test on the cylinder with the broken spring. The bulletin also says that “if no cylinder leakage is observed it will be necessary to replace all valve springs on both banks if the vehicle is built between June 1, 2020 to September 15, 2020.”
The bulletin also indicates that the above fix only applies to the following 6.2L GM V8 engines: L87, LT1, LT2 and LT4. For all other current GM V8 engine RPOs (L82, L84 and L8T), the service department is instructed to “just replace the affected valve spring,” and that if they determine there is a cylinder leakage, it “will be necessary to inspect further to determine the extent of the engine damage to determine correct repair required.” GM is also requesting that the service department send back valve springs from affected engines for further inspection.
This service bulletin can affect a very large range of current GM vehicles. The LT1 and LT4 V8s are found in the Chevrolet Camaro, while the LT2 V8 powers the Chevrolet Corvette. The L82 and L87 V8s are found in the latest GM full-size truck and SUV models, while the L8T is offered in the Chevrolet Silverado HD and GMC Sierra HD trucks, along with the Chevrolet Express van.