Strange V8 Engine Sounds Are Normal, Says GM
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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.
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I got a 50 year old ford that only ticks when ot needs an oil change and runs 50 to 70psi oil pressure. Maybe time to switch brands.
On a serious note I wouldnt be happy about a new Ford or GM sounding like a worn out Hyundai either. I reckon they’re saying it’s normal because they have no idea what it is
The ‘strange noises’ probably are common and considered to be ok because so many different factors such as timing and idle air controls, who knows…
To be clear, my Chevy truck was great until; I replaced the dash cluster for the second time, replaced the left front wheel bearing assembly twice and the right once for ABS sensors, the clutch slave cylinder failed, the screws holding the console on the roof fell out and both brake lines rusted and failed at the same time leaving me with NO BRAKES with a trailer on! Fortunately I had manual transmission and trailer brakes.
It’s too bad, I loved my 2500HD until all of this happened. The high point of the truck was the 6.0L engine… I’ll never buy another Chevy truck.
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!
Install a loader exhaust on it. Every LS1 I’ve had has been a gem (6). Yes, a boatload of noise, but they have all moved like the wind, but sounded like a tornado.
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