GM’s recent V8 engines have experienced check engine issues caused by faulty valve springs
The issue is addressed in a recent service bulletin from GM
GM vehicles equipped with V8 engines may show a service engine light as well as experience various other problems including misfires and odd noises. The issue is apparently caused by faulty valve springs according to a recent GM service bulletin.
The bulletin instructs GM technicians to check for a broken valve spring and perform a cylinder leak test if needed. If the test proves conclusive, service departments are instructed to replace all valve springs if the vehicle was built between June 1 and September 15 2020.
According to GM Authority, this only applies to the L87, LT1, LT2, and LT4 6.2-litre V8 GM engines. For L82, L84, and L8T V8 engines, dealers are required to replace the problematic valve spring.
The scope of the affected V8 engines is wide and touches a range of models including the new Chevy Corvette, the Camaro, and the GMC Sierra HD and Silverado HD heavy duty trucks.
So this finally explains it… Just got a new 2020 silverado trail boss w 6.2 this month & it suddenly started acting up & shut off on me in traffic & wouldn’t restart. Aftr a long process of getting it towed & back 2 dealer (thanks roadside assistance) they spoke w GM mechanics & determined it had a broken valve spring & that caused catastrophic engine damage. They r replacing the engine & components now. I’ve been w/out it for 11 days & supposed to 2 get it back next week sometime I guess. What was my dream truck is now a nightmare. & i called customer service 2 complain & c what they were going 2 do 4 me & they were 2 get back 2 me in 24 hrs & it took them a week 2 get back 2 me. This is so frustrating.
Don’t buy GM Junk
Second day of my new 6.2 Silveradoit was idling and shut off Tried restarting it would not eep running. 2 weeks in the shop and no diagnosis as of yet. It is a High Country with 70 miles. Not a happy camper.
Purchased 2020 GMC Sierra AT4 6.2L. Engine died in traffic after 1 week with less than 300 miles on it. Broken valve spring. Dealership wanted to blame me due to new Borla exhaust and K and N air filter. Unbelievable!