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Chevrolet and GMC Truck Information: Silervado, Sierra, and Colorado

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The 5 Most Common GM 2.7L L3B Engine Problems

June 8, 2022 by Jake Mayock 18 Comments

The 2.7L L3B turbo engine debuted in 2019 as the base engine in Chevrolet Silverado 1500 and GMC Sierra. Although the engine was specifically designed as a truck engine, it has been used in other GM vehicles. It replaced the 4.3L V6 LV3 engine and was recently updated for the 2022 model year refresh to improve its overall performance.

The engine is an inline-four-cylinder configuration that initially provided 310 hp and 348 lb-ft of torque before the engine refresh. With the recent update, the engine torque improved from 348 to 430 lb-ft of torque in the light-duty pickups. The engine is mated to an eight-speed transmission with a maximum towing capacity of 7,200 pounds and 2,280 pounds payload capacity.

Compared to other truck engines, a four-cylinder engine seems small. However, it is equipped with a dual volute turbocharger which gives it extraordinary capabilities — 0 to 60 in 6.8 seconds. The turbo design brings exhaust in from both sides, which helps to eliminate the usual pulsing most turbos have, giving it a swift response time. Besides quick response, the engine has better fuel economy than the 4.3L V6 with an EPA-estimated 19 city, 22 highway and 20 combined.

The engine features the Active Fuel Management system, and even though GM seems to be discarding the system in their other engines, it was still retained in the 2022 engine refresh. The engine has an electro-mechanical variable camshaft used to alter the lift of the intake and exhaust valves and operate three different camshaft profiles. The profiles include high valve lift for full power, low valve lift for a balanced operation, and Active Fuel Management for light load conditions. The 2.7L L3B turbo engine has been used in the following vehicles:

  • Chevrolet Silverado 1500
  • GMC Sierra 1500
  • Cadillac CT4
  • Chevrolet Colorado
  • GMC Canyon

2.7L L3B Engine Problems

Common 2.7L L3B Engine Problems

Since the engine was introduced, the complaints about it have been limited. However, this doesn’t mean that the engine is faultless. Discussed below are possible problems you should look out for in the 2.7L L3B engine:

  • AFM system failure
  • Carbon buildup
  • Injector failure
  • HPFP failure
  • Poor fuel economy

1. GM 2.7L L3B Possible Active Fuel Management System Failure

The 2.7L engine has featured an Active Fuel Management system since its launch in 2019. Although General Motors seems to be phasing out the Active Fuel Management system for the more advanced Dynamic Fuel Management system, the refreshed 2.7L engine still retained the AFM system.

The Active Fuel Management system was initially known as Displacement on Demand and debuted in Cadillac’s 1981 L62 V8-6-4 engine. However, the system was suspended shortly after launch due to reliability issues and later reintroduced in 2005 as the Active Fuel Management system (AFM). The system shuts down some engine cylinders during light driving conditions and reactivates them when more power is needed to help improve fuel efficiency.

Despite the system’s improvements, drivers have continuously complained about it. The system uses special lifters to activate or deactivate some cylinders depending on the engine’s need. However, these lifters don’t last long in real-world driving conditions, making them susceptible to catastrophic failures. Some customers filed a class-action lawsuit against General Motors, alleging that the AFM system lifters malfunctioned and failed, causing significant issues or even total engine failure.

Although the company is yet to send out a lifter recall, it has agreed to cover repairs through extended warranties. There have also been complaints that the replacement parts used by General Motors were equally defective and still failed.

Symptoms of AFM System Failure

  • Excessive oil consumption
  • Low engine power
  • Sudden stalling
  • Hesitant acceleration
  • Difficulty downshifting

The Active Fuel Management system failure has been minimal with the 2.7L L3B engine, but that doesn’t mean it is impossible. The system failure could cost an arm and leg to fix, but you can take any of these proactive measures to prevent its breakdown.

  • Tune it out using tuning software like HP Tuners.
  • Get an AFM disabler such as Range Technology’s AFM Disabler. Unlike HP Tuners, AFM disablers work without flashing the ECU, making it undetectable.
  • The third and most effective way to deal with this issue is through Active Fuel Management (AFM) or Displacement on Demand (DOD) delete. The procedure requires replacing all AFM parts with standard non-AFM parts. This procedure is the most expensive and labor-intensive, but it eliminates the chances of catastrophic and costly engine failure.

Check out our full guide on disabling AFM and DFM.

2. 2.7L Chevy L3B Carbon Buildup

Every car with the direct injection, including the 2.7L L3B engine, suffers from carbon buildup in the intake manifold over time. With direct injection, fuel is sprayed directly into the engine cylinder for a higher level of precision, resulting in greater engine power, reduced emissions, and increased fuel efficiency. However, direct injection engines are not all perfect.

The engine design leaves room for carbon buildup in the intake manifold — unlike port injection, which sprays into the intake manifold, giving a natural cleaning effect, direct injection sprays inside the combustion chamber. Carbon deposits from blowby gases gradually gather in the intake port and valves. Consequently, the airflow into the combustion chamber is affected, reducing engine performance.

Symptoms of Carbon Buildup

  • Heavy exhaust fume
  • Reduced fuel efficiency
  • Engine misfire
  • Poor acceleration
  • Rough idle
  • Illuminated check engine light
  • Cold stalling
  • Power loss mostly while on high speed

The design of direct injection engines impedes cleaning agents used in gasoline from reaching and cleaning the manifold because fuel never contacts the stem side of the valves. Some manufacturers like Toyota and Subaru have started adding manifold injectors to their direct-injection engines, which occasionally spray fuel to wash away carbon deposits in the manifold.

Using oil with low volatility levels would help minimize the buildup of carbon deposits. You can also install an oil catch can in the vacuum line from the PCV valve, thereby limiting the amount of oil reaching the valves. An oil catch can is a canister-looking container that helps trap contaminants and oil returning from the PCV valve but needs to be emptied regularly.

Both measures suggested above are only preventive. If you have deposit buildup in the manifold, you will have to get them removed either by physically cleaning the valves or walnut blasting.

3. GM I-4 Turbo L3B Engine Clogged Injectors

Direct injection engines introduced injectors that sprayed directly into the combustion chamber. The injectors are located at the top of each cylinder and get pressurized fuel from the high-pressure pump to overcome the engine compression pressure. Although the injector location allows for more precise fuel delivery, it also affects the injector longevity.

The injectors are exposed to the extreme heat generated in the combustion chamber and particulate matter — a byproduct of the engine combustion. The continuous exposure of the injectors to particulate matter after several thousands of miles causes carbon buildup to clog the injector tips, consequently impeding their performance.

Symptoms of Clogged Injectors

  • Illuminated check engine light
  • Engine misfire
  • Reduced fuel efficiency
  • Lean fuel mixture
  • Reduced engine performance
  • Crank but no start
  • Rough idle

While the injectors are expected to last the engine’s lifetime, it is not uncommon for them to fail. Using fuel additives has proven to help keep the injectors clean and perform efficiently. If your injectors get clogged, you may want to consider cleaning them before opting to get them replaced. However, if cleaning doesn’t help, you should change them altogether.

4. 2.7L L3B High-Pressure Fuel Pump Failure

Unlike port injected engines with one pump, direct-injected engines usually have two pumps. The system has one low-pressure and a high-pressure pump. The low-pressure pump sits inside the fuel tank and transfers fuel to the engine. Upon getting to the engine, a high-pressure pump pressurizes the fuel before sending it to the injectors. The engine needs such substantial pressure to overpower the compression pressure.

Since the high-pressure pump operates under a lot of pressure, they are susceptible to failure after an extended period of use. Ideally, the pump should last well over 100,000 miles or more, depending on your driving habits. Asides from reduced engine performance, you may also notice the following symptoms when the pump fails:

Symptoms of High-Pressure Fuel Pump Failure

  • Reduced fuel efficiency
  • Low fuel pressure
  • Weird idle
  • Power loss
  • Engine surge
  • Delayed start
  • Engine stall
  • No start

A failed low-pressure fuel pump could also trigger most of the aforementioned symptoms. So, you may want to check the condition of the low-pressure pump before assuming that the high-pressure pump is the source of the problem.

5. GM 2.7L L3B Engine Poor Fuel Economy

Considering that one of the key marketing strategies used to promote this engine was its fuel economy, one would expect that it lives up to its billing. However, some drivers have complained about terrible gas mileage despite the engine’s Active Fuel Management system and the start/stop technology. The source of the appalling EPA number is not far-fetched from the turbocharger.

The engine turbocharger spools up and gulps gas whenever you floor the accelerator. Continually flooring the gas pedal will only get you awful gas mileage. Understandably, there is always that urge to test your turbocharger’s limits. However, before submitting to such a desire, always remember that you are pouring gasoline out the window. Thus, you should caution yourself and regulate your driving habit if you intend to average the EPA-estimated MPG.

Chevy/GM 2.7L L3B Engine Reliability

GM got backlash from customers when it announced its plan to replace the 4.3L LV3 engine with the 2.7L turbocharged engine. While drivers were initially reluctant to opt for the 2.7L engine, most drivers had little or no complaint.

Apart from potential AFM system failure, whose chances are still very slim, other problems highlighted are all issues a driver could encounter with a direct injection engine and a turbocharger. Ultimately, your engine’s reliability depends on how well you maintain it. While the 2.7L engine is smaller than the 5.3L and 6.2L V8 engines, it is packed with technology designed to deliver decent fuel efficiency and outstanding performance. Overall, it is a splendid commuter truck with adequate towing capacity, perfect for occasional hauling.

Filed Under: Chevy & GMC Trucks

About Jake Mayock

Jake is an automotive enthusiast who has been blogging about Chevy's and European cars for years. With technical knowledge on performance modifications and engine problems, Jake has a passion for helping car enthusiasts fix problems and achieve their performance goals.

Reader Interactions

Comments

  1. Allen Bettigole says

    June 8, 2022 at 12:59 pm

    I hate to say this but I’m not buying any more GM trucks. At 38k left front tire was leaking out the sidewall, dry rot. At 40k my Silverado front rotors were rotted away on one side one rotor when I checked the front brake pads. Pads were only 60 percent worn. At 62k the fuel pump housing had a rust hole in it and I had an evap leak. A week later the tourqe converter started slipping on a hill, now I had to pay for a transmission and I have AFM disabled. I now have 64k on a 2011 Silverado Z71 and holding my breathe. I’ve been in the car business my whole life, retired as an owner in a transmission shop and I take care of my vehicles. Next time if there is a next time it will be a Toyota.

    Reply
  2. Sir Victorino Papefu says

    June 25, 2022 at 5:00 pm

    We just got two months ago the 2022 1500 Silverado 2.7L, crew cab, LTD Custom 4×4 (310 horsepower, and 348 torque), new.
    We have heard people complaining that no 4 cylinders should be in a truck, though these are big cylinders inline taking over 6 qtrs. of oil.
    All I can say is this truck runs really great. I myself use premium gas (over 91) just to be kind with the turbo, though you can use 87 octane with no problems.
    Also people complaint about the gas mileage. We have made up to 25.6 mpg in this truck. What I recommend is every time you start a day, reset a new trip to “0”. If you do not do it the truck will show the gas mileage calculation of the previous trip still running on. You may had accelerated high for a need or whatsoever, and then the truck mileage will be calculated based on the trip you have been running since. So, reset it to “0” every time, and you will see the difference.

    Reply
    • Tyler Osborne says

      July 19, 2022 at 10:36 pm

      Thank you Victorino. That was very helpful.

      Reply
  3. Jack says

    July 14, 2022 at 11:04 am

    Just return to a naturally asperated fuel delivery system, the mileage will actually improve and go forever with this big bore four! Too much intelligence from these millennial techs with too much time on their hands make more problems than they help. Don’t fix it if it isn’t broke. Just produce and sell, that’s the ticket for our fast pace society. Keep it simple stupid. Less engineers more progress. You guy are killing us out here. Your making commonsense an oxymoron like politicians make humankind an oxymoron. call on me!!!

    Reply
    • Joe Millenial says

      July 19, 2022 at 11:22 am

      Ok Boomer. Lets go back to carbs and points ignition.

      Reply
  4. Glen williams says

    July 24, 2022 at 11:30 am

    I just bought a regular cab short box 4×4 it is the refresh and I was very hesitant to buy it because of the four cylinder engine. I have so far been very impressed with this engine. I would buy it again in a heartbeat. The power is amazing.

    Reply
  5. marvin says

    July 25, 2022 at 10:28 am

    Worst truck I have ever owned oil leak that the dealer cant fix

    Reply
    • Jake Mayock says

      July 25, 2022 at 6:49 pm

      Hey Marvin – where is the oil leak coming from and how bad is it?

      Reply
  6. James says

    September 7, 2022 at 7:17 am

    Just bought the new 2022 1500 Silverado 2.7L, crew cab, LTD Custom 4×4 and am having shuddering issues when accelerating and decelerating at low speeds (25-45mph). RPM’s are not dropping. I did alot of digging and it seems the consensus it’s the AFM. I am assuming this is the LB3 motor. Do you know if the Range Technology’s AFM Disabler will fork for the 2022 LB3 I-4? It says only for V6 and V8. Don’t want to buy it and plug it in if it is not compatible.

    Reply
    • Billy J Glasgow says

      December 19, 2022 at 6:39 pm

      That’s the 8 speed transmission problem not AFM

      Reply
  7. Richard says

    September 10, 2022 at 8:38 am

    The company I work for just purchased a Chevrolet 1500 standard cab two wheel drive with the 2.7L L3B engine with 310HP and 430 ft-lbs of torque. I’m impressed. It pulls like a V8 on some mile long hills that I go up for some of my deliveries.

    Reply
  8. Dan Sherwood says

    September 23, 2022 at 7:55 pm

    Bump it up to 350/500 with 30mpg and my next truck will be a Canyon denalli…

    Reply
  9. wildrose says

    October 19, 2022 at 9:19 am

    Bought my 2022 Chevy Silverado 1500 in July. Just took it in for the first Oil change at 7600 miles. The dealer ship called and said there are metal shaving in my oil. That is an engine replacement. I am not a happy person right now. I love Chevy but they are make big mistakes. Now I make that big payment every month and have not vehicle until they get the engine replaced.

    Reply
    • Jake Mayock says

      October 20, 2022 at 8:29 am

      Sorry to hear, this is a frustrating issue. I know the problem here probably wasn’t caused by this but on a brand new engine you really should get the oil changed after the first 1,500 to 2,000 miles and then again at the first 5,000 miles. And on any engine, change it every 5,000 miles regardless of what the recommended service interval is…10,000 mile service intervals are a bad idea even if that’s what the manuf. suggests.

      Reply
      • Michael Walker says

        December 31, 2022 at 7:40 am

        I agree with the oil change interval. I changed my at 1500, then 6000 then 10,000 and 5000 from then on. It is easy to keep up with that way. Turbo charged engines usually require a more frequent oil change interval.

        Reply
  10. Sir Victorino Papefu says

    October 20, 2022 at 9:52 am

    It can happen in a new engine first oil change.
    Did he showed it to you?
    You can also change yourself the oil under warranty, and despite what they can tell you. Just keep the receipts and write it down in the book.

    Reply
  11. Uttaka says

    December 6, 2022 at 12:47 pm

    I drive a 2019 Fleet version of this engine, has almost 290,000k going strong. Other than the abuse of my co-workers, the ENGINE held up find. The other materials are GM cheap as usual. Hard to clean, so no one does, switches have all rubbed off, but one thing GM is good at is standard logical layout, at least in their commercial lines. The fuel saving paint (aka GM bean countin’ because they know the domestic market will buy anything they sell) is chipped and very delicate. These vehicles ding very easily.

    Reply
  12. GoWest says

    December 17, 2022 at 8:16 pm

    The Silverado 4 cylinder turbo is intriguing. I liked our ’07 Avalanche which, although a half-ton, had an optional 2500-series drivetrain (6.0 Vortec, heavy duty transmission, 4.10 gears). Great for towing a 6,000 lb travel trailer. The only problem was excessive oil consumption after 100K miles, likely due to the Active Fuel Management system. All GM trucks still used AFM when I was shopping for a new truck in 2017; so I ended up with a Titan (no cylinder deactivation, no turbo, no start-stop technology). I plan to keep the Titan for many more years, but if it ever gives out I’d want to return to Chevy. Hopefully GM’s current-generation Dynamic Fuel Management won’t cause the same long term engine issues as the previous Active Fuel Management.

    Reply

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