2.7L L3B Engine Problems

The 5 Most Common GM 2.7L L3B Engine Problems

Jake Mayock

Meet Jake

Jake is a founder of 8020 Media and has been creating automotive content online since 2017. He has been the lead writer for Chevy Trucks and has transformed it from the old and outdated site it was into what it is today. Jake creates a ton of GM related content for the 8020 Media YouTube channel and specializes in Duramax and Vortec information but has a wealth of knowledge across all GM cars and engines. Jake believes the L5P is the best diesel on the market today.

The 2.7L L3B turbo engine debuted in 2019 as the base engine in Chevrolet Silverado 1500 and GMC Sierra. As the standard truck engine you would hope it has the durability and longevity necessary for it’s intended purpose.

While the engine has proven to be quite reliable, it does suffer from a couple common problems with the AFM system and things that come with owning a turbocharged engine, like the high pressure fuel pump, injectors, and carbon buildup.

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. 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. 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 manifoldunlike 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. 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. 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 HPFP 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. 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 there was a lot of skepticism when this engine was released it has turned out to be very reliable.

Apart from potential AFM system failure, which has been few and far between, 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. 

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37 Comments

  1. 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.

    1. I am with you on this. I had a fleets of Astro work vans and a Tahoe every one of them the fuel pump failed at 149950km. If you only had one you may think 150k is adequate life expectancy but when every unit failed at the same mileage it reeks of programmed failure. My wife’s Toyota van had 300k when we sold it and no fuel pump issues.

  2. 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.

    1. I have a 2019 Silverado 1500 crew cab 2wd with the 5.3 on a trip from Georgia back to Texas my truck literally got 32.1 mpg average for 25 miles, my inlaws have the same truck with the 2.7 and averages best 21…… I’d have to say the 2.7 is a failure on all accounts…..

      1. I averaged 42 mpg in my 2500HD 4×4 one time for about a 15 mile stretch! It was coming down off a mountain range at low speed, but since we’re being ridiculous I thought I would share too. Nobody gets anywhere near 30mpg in everyday driving with a 5.3 over any period of time, 20 maybe.

  3. 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!!!

      1. I sure miss those days, heavy unburnt gas fumes, smog, 10mpg, rough idle, trade ’em in at 70k because all the vacuum leaks are making it run like an old lawnmower. Ah, the good ol’ days.

    1. Is GM releasing a simple non-turbo version of the 2.7 L3B engine in the new 2023 Colorado and canyon work truckS?

  4. 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.

      1. I bought a 2023 Chevrolet Silverado crew cab four-wheel drive 2.7 l turbo I’ve noticed the plastic oil drain plug ,has a drip drip drip going on, got the first oil changed out 4,000 MI the dude said it’s been leaking ,so I put a new plastic oil drain plug in it now this one leaks too.

  5. 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.

  6. 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.

  7. 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.

    1. 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.

      1. 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.

  8. 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.

  9. 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.

  10. 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.

  11. I have a 2021 Silverado 1500 with the 2.7 and it is a 4×4. After two years and 82,000 miles, the camshafts failed and had to be replaced. Otherwise the pickup is flawless. No issues, zero. Don’t be mistaken, it is NOT a V8. It has good performance but real world testing has shown the camshafts and valve train are not up to GMs reputation of small block V8 reliability and durability. The best of the best has been the first generation LS family of 5.3 and 6.0 engines. I currently have a 2010 Tahoe with the 5.3, so far…so good.

  12. I’ve got a 2022 Chevy Silverado with the 2.7 liter turbo. First thing to go wrong was the oil cooler was leaking. It took 3 months to get a new one. I’ve had it in the shop multiple times for a noise when I shut it off. The shop replaced the throttle body and that didn’t fix it. I did some research of my own and it turns out that other people have had the problem and it’s the wastegate actuator. Now I’ve got another appointment for that because the dealership doesn’t believe me that it’s still making the noise and told me it was normal. Not a happy Chevy owner at all. Oh and I forgot to add that I still need to get my ecm replaced because they think that caused the check engine light to come on. But the code was for the injectors. That’s probably the next thing to go. I’m just going to go back to buying dodges. At least all I had to worrying about was the transmission going.

  13. I have a 2020 Silverado 1500 that I’m not impressed with. At 20,000 miles the starter went it took 6 weeks to finally get one. At 47,000 miles the TPS went and you can’t just buy the sensor you have to replace the complete throttle body. At 48,000 the motor started ticking loud 2 of the roller rockers on number 3 cylinder fell apart and also took out the camshafts. Now I’m just turning 50,000 and the transmission is acting up.
    NOT TO IMPRESSED !!!

  14. Change all the transmission fluid to mobile 1 lb HP. Theres a technical service bulletin about it
    Fixed a 2017 gmc denali sierra 1500 with 8 spd this way 4 days ago. Shuddering from 25-65 mph he had
    Is a known fix for that

  15. I had a 2019 dodge 1500 crew cab with the 5.7 and 3.95 rear. I totalled it out around Christmas and had to buy a new truck in a hurry. I purchased a 2022 chevrolet crew cab LT truck. It was the cheapest I could find with nav and a crew cab and it has the base 2.7 with turbo. It by no means runs like a hemi but the little 4 banger really runs good for being in a full size truck. The mileage has been around 22MPG and that was about 5 MPG better than the dodge.. You can definitely tell it has a 4 cyl when you push it hard. If you drive it easy it runs smooth and has plenty of power to merge onto a beltway

  16. My friend bought a 2023 model, 6 mos later, the engine is making a loud whistling sound…. Not normal turbo noise. Transmission is having an issue, and it’s having electrical issues… this is the third or fourth trip to shop… my 160,000 mile Hyundai still purring on, not one issue…

  17. My 2022 Silverado LTZ with 3000mi is at the dealership service garage for engine code P0201 PO2EE cylinder #1 fuel injector- control circuit. 2 weeks now, no parts available. Looking for any insight, experiences, thoughts. Also, any suggestions for communicating with someone higher up the ladder at GM? I’m sure it will get fixed eventually but am worried about more issues down the road. Very frustrated!

  18. I presently am driving a 2019 Chevy Colorado 17,500 miles with the 3.6 engine and I have gotten 26.5 on trips to my hunting cabin and around town 14.5-16.5.
    I was just going to consider a new 2023 Chevy Colorado with the 2.7, but after reading all of the notes and updates I will be keeping my 2019 and will begin looking at Toyota Tacoma’s.
    Too bad for GM as they always had great engines but like all of AMERICA, everything is CHANGING and not for the better.

  19. Come on, you mention Toyota and Subaru have port injection added to combat carbon but you intentionally avoided mentioning Ford also having added port injection to their Ecoboost engines.

  20. Bought a 2019 Silverado 2.7 Turbo a month ago. It’s been in the shop for two weeks. Started with the ECS module going out. Had to limp it to a dealership. Got that replaced and they found out the throttle body was bad. They say there is only 5 in the entire country and is on back order. I haven’t even put the new tag on it. Looks like I will be making the first payment on a truck I haven’t driven but 250 miles. First Chevy I have ever owned. At this rate, it’s gonna be the last.

  21. I bought a 2019 silverado 2.7T they said it would tow 6800 lbs. Finally i got a camper 4600 lbs. Tried to tow the camper would not go into 8th gear. ANYBODY have the same problem. Or know of this happening.

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