Strange V8 Engine Sounds Are Normal, Says GM
102
Sponsored Links
One of the scariest moments for any vehicle owner is when their engine begins making weird noises. Lately, a few GM V8s have been making several different noises, including chirps, squeaks or sputters, concerning many owners. Now, an article on GM TechLink says these noises are normal.
GM 5.3L V8 L84 engine
There are four common sounds produced by the affected engines:
- Catalyst light off – occurs on start, where spark timing is retarded for rapid catalyst converter warm-up, and may last roughly 30 seconds. Notably, this warm-up sequence is not triggered on all start-ups, as the vehicle must have sat for an hour or longer.
- Engine restart – following complete engine shutdown coasting down to 14 mph, spark timing is retarded to prevent engine overspeed/torque bump. This noise lasts only abut a second.
- Auto-start – at the end of an engine stop/start shutdown, spark timing is retarded to prevent engine overspeed/torque bump. This noise lasts only abut a second.
- Throttle blip – a light blip of the throttle while in park/neutral results in spark timing being reduced to prevent engine overspeed. This sound is hardly noticeable and hard to reproduce.
GM 6.2L V8 L87 engine
The 6.2L V8 L87 gasoline engine and the 6.6L V8 L8T gasoline engine are known to produce these peculiar noises under various conditions. These engines are found in some 2019-2023 Chevy Silverado 1500, Silverado HD, Chevy Tahoe, Chevy Suburban, GMC Sierra 1500, GMC Sierra HD, GMC Yukon and Cadillac Escalade models. Notably, these sounds are much more noticeable in the L87 and L8T engines than in the 5.3L V8 L84 gasoline engine.
GM 6.6L V8 L8T engine
It’s worth noting that comparing these noises to other, similar vehicles is not recommended, as the noises may be different from one vehicle to another. This could result in unnecessary repairs, as the sounds are a normal characteristic of a healthy, operating engine. Replacing the engine or internal components in an attempt to fix the sounds will not reduce or eliminate them.
Subscribe to GM Authority for more GM engine news, and around-the-clock GM news coverage.
- Sweepstakes Of The Month: Win a Corvette Z06 and 2024 Silverado. Details here.
Sponsored Links
Listen GM trucks are great until they leave the dealership then your on borrowed time. They are time bombs.
How about the LS1 and all its noises? Piston slap, valvetrain noises , stupid thing sounds like it’s got loose marbles in the cylinders , but I guess this is ” normal” . It’s an embarrassment to drive my LS1 powered car!
I have a 2021 Silverado, running on the highway 55 to 60 mph all the lights came on on my dash, when I got to my building where I work there was a really bad knocking noise, I had the truck towed to the dealer it took them a week when I got it back, they told me they replaced the oil lifters on the left Bank of the engine driver side. My question is the right side is it going to be the same? So from the paperwork I got from the dealer they only replaced eight oil lifters on the left side, they did not touch the right side of the engine. I think it’s time to get rid of it before the warranty is done and I don’t want to get stuck with this repair.
Don’t worry pretty soon you’ll be able to trade your trucks in for some electric pile that can’t carry any cargo or tow anything for more than an hour before you have to stop and charge it for 2. The perfected the V8s about 20 years ago now they’ve been going backwards since. Now they’ll start all over with electric time bombs.
Speaking of EVs. GM asked me to complete a survey and by question 4 the questions were about how I feel about them. Two questions later I got a message reading that I didn’t answer the questions the way they liked so the survey was over. The area where I live is NOT ready for EVs and until I can charge a vehicle as fast as I can pump gas and then drive 500 miles I’m sticking with the Dino juice
YIKES!! I had the check engine light come on the week before a scheduled maintenance appointment for my 2022 Sierra Denali with 9,980 miles on it. It went off for a short time, then came back on the day before the appointment. I took the truck in and alerted the service manager of the issue. After servicing the truck, the technician that worked on it, heard a suspicious engine noise and the check engine light remained on. The diagnostic apparently showed low oil pressure, so they wanted to replace the oil pump. The dealer R&R’d the oil pump, but it didn’t fix the problem, the light remained on. They pulled the oil pan again and found two rod bearings had turned rendering the motor useless. An entire engine replacement was the only fix. Engine ordered, but the dealer has no idea when it will arrive, saying it could take up to two months or longer.
Now it sits at the dealership waiting for a new motor with no idea on when the new one will arrive. Someone mentioned a class action lawsuit. Is that a thing or saber rattling? Anyone have ideas? The price for the truck was 70k plus. Do I stop making payments, no wait…I paid cash! Damn! Am I SOL on this?
What V8 engine is in your denali?
L-87 6.2 Liter V-8.
I can see all the GM engineers with their clipboards QC’ing the 2023 ZR2, after it has been started, and saying to themselves….”THIS is what we want our trucks to sound like”. Mine sounds like pure hell and I regret ever buying it. It looks good and rolls good….that’s about it. I have a 2008 Tundra 5.7 with 230K miles on it and it sounds and drives way better than my brand new $78,000 2023 ZR2. Glad I kept the Toyota.
@Tundra_Guy
To quote you “I have a 2008 Tundra 5.7 with 230K miles on it and it sounds and drives…” let me finish that; “drives like it did when it had 4 miles on it.”
I’ve had one bad Chevy, a 2007. Don’t get me wrong, I loved the truck, good looking, nice features and most of all a stick shift. It was nice for 13K miles then all hell broke loose and GM spent a lot of warranty time and money and never really got fixed. I gave up at 45K. Next truck was another Chevy 2500HD, a 2010 and I figured I had bad luck, that’s all. I ordered it and optioned it almost exactly the same and of course another stick shift. I made it home and when I went to the jobsite the next morning the slave cylinder failed on my way, it had 35 miles on it. I rev matched to shift without using the clutch and called the dealer. I managed to contain my anger telling them I needed it towed and what the problem was and also that my situation was serious because I needed it for work. I got some static from the service department because they said “if there’s any transmission damage it won’t be covered because you shifted without using the clutch and those damages won’t be covered”. I told them I’d already contacted my lawyer which was true, I had given him my credit card to put a $1 retainer on it just in case this escalated because I intended on filing suit if this went sideways. In the end my truck was down almost 3 weeks and the only thing that the dealer offered was a trip to National Rental when I could get a rental van! I took it for the rest of the week all out of pocket. I ended up buying a 2 year used Ford F350 Super Duty the next week. I really didn’t like the Ford for a while but after a month it proved to be an excellent truck. I kept the Chevy for almost 3 years because to be honest I had almost $50K in sunk costs. I had another slave cylinder go a month later, they replaced it and the flywheel, a month later the second replacement slave cylinder went. They replaced the slave, the transmission, the flywheel, pressure plate and clutch disc and that problem finally went away. The rest of my time with that truck was fairly event free but I had it three years and didn’t have the use of it for 8 of those months for mechanical failures. One of my employees got a Tundra and I laughed at his ‘pretend’ truck because I was thinking of the Toyota T100 pickups, funny thing is, he bought his truck a year after I bought my ’07 and you know what? IT’S STILL RUNNING PERFECTLY with just over 300K miles!
I’m still driving my Ford, screw GM.