Common Problems With The GM 2.7L TurboMax Engine, According To Drivers

GM's 2.7L TurboMax engine is a great example of how automakers are favoring downsizing and turbocharging in favor of high cylinder counts and large capacities these days. The engine, which was originally known by the code L3B, debuted in 2019 and was set to replace the aging 4.3L V6 engine, which produced both fewer horsepower and fewer torques, despite two extra cylinders and a larger capacity. It also weighed less, and was more fuel efficient too, so a win-win for GM and customers too.

While the L3B powered models such as the Silverado 1500 and GMC Sierra 1500 from 2019 onwards, it wasn't until 2023 that GM would introduce the TurboMax name. At this point, the 2.7L inline-four benefitted from some important updates too, which saw torque swell from 348 to 430 lb-ft, while power stayed constant at 310 horses. Despite Chevrolet clearly showing confidence in the revised Turbomax engine, offering a 100,000-mile powertrain warranty as standard, some buyers have begun to notice issues with the turbocharged inline-four. From troublesome misfires through to unusually high oil consumption, we explore the common problems experienced with drivers of GM models powered by the relatively new 2.7L TurboMax engine.

While oil consumption doesn't seem to be a drastic issue with the 2.7L TurboMax engine yet, owners are having to keep a close eye on their oil levels, and some have taken to shortening the service intervals from what GM themselves recommend. One owner takes to a Colorado owners forum to document their experience, and having covered over 70,000 miles in their 2022 model, they can speak from experience. The owner notes that, at around 3,000 miles into each interval, the consumption spikes dramatically, which results in them changing oil every 5,000 miles, or at 30% on the OLM (Oil Life Monitor). Chevy recommends doing so every 7,500 miles, but after seeing up to 1.75 quarts of oil disappear every 5,000 miles, the owner decided more frequent changes were in order. Oil life monitors aren't always accurate, so it's good practice to act before the OLM recommends you to do so anyway. 

This owner is not alone. Others have taken to sites like Reddit and other similar forums to make similar comments about their own experiences. These owners have also made similar changes to their servicing routines, with one stating that "once I get to about 35%, I need to take it in ASAP," when talking about the reading on their OLM. Another owner went to the dealer when concerned about losing roughly one quart of oil every 2,000 miles, only to be told that the dealer considers this sort of result to be acceptable.

Another headache that seems to be troubling owners of TurboMax-kitted GM models is misfires. Maybe it's down to the fact that these engines are relatively new, or perhaps they are just difficult to trace, but many owners are running into a brick wall when trying to have their misfires diagnosed. One owner of a 2023 Chevrolet Silverado — a model which we've reviewed — took to Reddit to document their experience, complaining of a misfire at higher revs, with rough acceleration that could be physically felt through the gas pedal. Despite taking it to Chevy dealers multiple times, an answer couldn't be found, as no code was stored — an issue experienced by other owners who expressed similar frustration in the comments.

Others have experienced misfires, but have managed to trace it back to faulty spark plugs. Now, Chevrolet advises that the plugs shouldn't need replacing until 97,500 miles, however owners are finding that plugs are going faulty much earlier than this. Other sources highlight spark plug degradation as a common concern with the TurboMax engine, which could well be the cause of the developing misfire issues owners are suffering from.

While, as with any engine, the TurboMax does suffer from some issues, it would appear that most owners are actually very happy with the TurboMax's performance and reliability. Once again, online forums are a great place to find feedback from genuine owners. When asked for their experience, Redditors made statements like "44,000km on my ZR2 so far, no hiccups whatsoever with the motor," and "I've got 33k miles on mine and it's been completely fine," which should help to buy the mind of any prospective buyers at rest.

GM brands such as Chevrolet and GMC also offer comprehensive warranties. This warranty will only now be expiring for owners of the earliest L3B-powered vehicle owners, so potentially, voices of owners with troublesome 2.7L-powered models will get louder now that the warranty is finishing. If oil consumption issues prevail, and misfires become more prevalent, the costs of repair are not likely to be cheap, and so those suffering from such issues will rightfully have cause for complaint.