GM 1.5 Turbo Engine Problems, Causes, Symptoms, And Solutions

The GM 1.5 turbo engine, found in some of the brand’s most popular models like the Chevy Malibu and Equinox, has faced widespread reliability problems. Owners have reported turbocharger failures, fluctuating oil pressure readings, cracked pistons, terrible blow-by, the persistent sight of a Check Engine Light, among other miscellaneous faults.

Though it was designed for fuel efficiency and performance in mind, serious questions have been raised about its long-term reliability. Specifically, we’re talking about General Motors’ Small Gasoline Engine (SGE), a diverse family of small-displacement engines ranging from 1.0-liter to 1.5-liter in displacement. So, are these GM 1.5 turbo engine problems that bad?

Let’s take a closer look at some of this engine’s most commonly-reported issues, as well as what’s causing them, and how you could fix them for good:

GM 1.5 Turbo Engine Problems Cheat Sheet

If you need a more in-depth break down of each specific issue, we’ll be covering that in more detail further below. But, for a speedy TL;DR summary of some of the more common GM 1.5 turbo engine problems, we’ve prepared this handy little table for quick reference:

Problem	Affected Models	Symptoms	Potential Fixes
Turbocharger Failure in Cold Weather	Chevrolet Equinox, Malibu, GMC Terrain	Power loss, limp mode activation, and reduced acceleration	Install a radiator cover, allowing the engine to warm up before driving, and replace the turbo if necessary
Erratic Oil Pressure Readings	Chevrolet Equinox, GMC Terrain	Fluctuating oil pressure (too high/low), and excessive oil consumption	No official fix from GM, but conduct regular oil level monitoring, and use high-quality synthetic oil
Frequent Check Engine Light (CEL) Activation	Chevrolet Equinox, Malibu, GMC Terrain, Buick Envision	CEL appears without error codes, with no noticeable performance issues	Use an OBD scanner to diagnose/reset, and ignore if no error codes, but practice routine maintenance
Cracked or Melted Pistons (Pre-Ignition Issues)	Chevrolet Malibu, Equinox, Buick Envision	Rough idling, misfires, excessive blow-by, smoke, as well as  high oil consumption	ECM reprogramming by GM dealer, and switch to recommended Dexos 1 full-synthetic oil
High Engine Temperatures & Blow-By Issues	Chevrolet Malibu, Equinox, GMC Terrain	Engine overheating, excessive carbon buildup, in addition to increased emissions	Regular cooling system maintenance, ECU remap, as well as using high-quality fuel & oil

Most Common GM 1.5 Turbo Engine Problems

As clever as it may be deep inside, the frequency of GM 1.5 turbo engine problems might suggest that it can also be a problematic motor. We’ll focus predominantly on the 1.5 turbocharged models, that is, the LFV and LYX engines. Moreover, we’ll also narrow this down to the variants that are sold here in the US, which were fitted in Buicks, Chevys, and GMCs.

Among the former, Chevrolet had the most commonly reported GM 1.5 turbo engine problems of the bunch. Some of these issues, in a nutshell, include experiencing turbocharger failure if you’re driving in cold weather. Not to mention the myriad of other issues, such as the erratic oil pressure readings. And, the Check Engine Light (CEL) is going off far too many times.

These are the most noteworthy GM 1.5 turbo engine problems, among a sea of other miscellaneous faults. Here are some of the most common issues you might encounter with the GM 1.5 turbo engines:

GM 1.5 Turbo Engine Problems #1 – Turbocharger Failure In Winter

The most infamous GM 1.5 turbo engine problem includes how the turbocharger would fail at colder temperatures. This can, in effect, prevent you from driving your car at all. And even if you’re able to get it going, it can leave a significant impact on your performance, as well as drivability. Worse, this issue can begin appearing with minimal mileage clocked in.

Apparently, moisture from the intakes can freeze up at lower temperatures, blocking airflow to the turbos. It should clear up once the intakes and engine heat up more. A Canadian owner noted the temperature to be as low as -45°C. There hasn’t been a permanent fix, other than dealers advising owners to buy a radiator cover, to then block off the turbo’s intercooler airflow.

As the turbocharger freezes and fails, it might otherwise prompt your car to activate its ‘limp home’ mode, which sharply restricts the speed you’re able to drive. Reading into the forums, we’ve noted one story, where an owner had their turbo fail in the middle of a long drive. It failed more than once, forcing them to abandon their car, only to have it affect their loaner car, too.

Another owner saw a “reduced power” message pop up on their dash, before losing power from the engine completely. In other cases, nearly caught in rear-end collisions or horrible near misses, owners experienced their vehicles losing power.. Unfortunately, this turbocharger issue is far too common. Unsurprisingly, its victims are mostly those who live and drive in colder weather.

Repair & Replacement Costs

• Estimated Repair Cost – $1,200 – $2,500 for a full turbocharger replacement, including labor. Now, if only minor components (such as the wastegate actuator) need to be replaced, then your repair costs may be lower, around $300 – $600.
• Is It Covered by GM? – Unfortunately, there’s been no official recall from General Motors. However, some warranty claims have been honored under GM’s 5-year/60,000-mile powertrain warranty if the issue occurs early.
• Related TSBs – GM did issue TSB #19-NA-137 advising dealerships on diagnosing turbo-related issues in cold weather. In addition, some owners have mitigated this issue by installing a radiator cover in winter.

GM 1.5 Turbo Engine Problems #2 – Fluctuating Oil Pressure Readings

Oil pressure gauges the flow of oil into the engine, which affects lubrication as well as cooling. Generally, most of us don’t have to worry about oil pressure. That is, unless you have a GM 1.5 turbo engine. They tend to have a habit of never keeping oil pressure at an even level. Sometimes, it might not have enough pressure, or at other times, far too much of it.

Just for context, here’s what varying oil pressures denote, to see how much PSI is too low or high for a typical car engine:

• • 20-30 PSI (oil pressure while idling)
  • 25-65 PSI (normal oil pressure)
  • 45-70 PSI (it gets pressurized while driving)
  • >80 PSI (too much oil pressure)
  • <20 PSI (too little oil pressure)

Alas, GM’s 1.5 turbo engines don’t follow these general guidelines and have oil pressures that could fluctuate nearly all of the time. More often than not, reaching dangerous levels. One owner saw how their 1.5 engines could see the oil pressure skyrocket from 30PSI to 70PSI, even while idling or driving steadily. This then ties in with heavy oil consumption or oil burning.

While it’s common, oil pressure can fluctuate randomly. So much so, that it appears that GM’s dealerships and technicians couldn’t replicate the problem. They’d report back to owners that everything is normal, and it’s possibly a feature of the engine to run at too high or too low oil pressure. Still, owners remain concerned about long-term damage and wear to the engine.

Repair & Replacement Costs

• Estimated Repair Cost – Diagnosing this issue alone costs around $100 – $150. If the oil pressure sensor needs to be replaced, then you should expect to pay $200 – $400. In extreme cases, excessive oil consumption may require engine rebuilds, costing you a whopping $4,000+.
• Is It Covered by GM? – General Motors has not issued recalls for this issue, and repairs are usually out-of-pocket by owners. That’s unless it’s covered under an extended powertrain warranty program.
• Related TSBs – TSB #17-NA-098 highlights oil pressure monitoring concerns. However, General Motors advises regular monitoring of the oil pressure readings rather than a specific, permanent fix.

GM 1.5 Turbo Engine Problems #3 – Seeing A Check Engine Light (CEL)

As scary as it might seem, the Check Engine Light (CEL) is quite useful. It can alert you early on to a possible issue with your vehicle. You could then take this as an opportunity to have it checked out as quickly as you can, before the problems snowball into something worse. A CEL can even light up in your dash for simple issues, such as not tightening your gas cap properly.

In the case of those cars fitted with a GM 1.5 turbo engine, the CEL can appear far too frequently, even when there aren’t any problems. We’d call them false positives. Many owners of these engines spotted the CEL showing up, with no other noticeable signs and symptoms of underlying issues. This was confirmed when diagnosed with an OBD diagnostics scanner.

Once again, no error codes popped up, which means there aren’t any problems. Yet, it hasn’t failed to induce fear in those owners, who think that something bad is brewing. This does appear intermittently, making it hard for mechanics to replicate the issue. Therefore, there hasn’t yet been a permanent solution to this issue of the check engine light flashing or blinking regularly.

Owners are left with two fixes, as GM themselves never released a patch. The first is to bring along a diagnostic (OBD) scanner tool. Once a CEL does show up, plug that into your car, and see if there are any errors. If there aren’t, you can clear out the CEL from flashing on your dash. The other fix, as recommended by GM dealers, is to take the risk of ignoring the CEL altogether.

Repair & Replacement Costs

• Estimated Repair Cost – A basic OBD-II scan costs $50 – $100 at a dealership or auto shop. If a minor sensor is the underlying cause, repairs could range from $100 – $500. If no issue is found, then you could get the CEL reset for free, most of the time.
• Is It Covered by GM? – So far, you won’t get warranty coverage unless a deeper mechanical fault is found. Some owners have managed to resolve this issue with regular software updates at some General Motors dealerships.
• Related TSBs – There haven’t been many major TSBs for related problems. However, software updates have been issued for various ECM-related issues affecting engine sensors, which might fix the CEL.

GM 1.5 Turbo Engine Problems #4 – Cracked Or Melted Pistons (And Blow-By)

When GM’s new 1.5 turbo engines went into mass production with the Chevy Malibu, severe problems started appearing. The most memorable among them is how these engines can run so hot, due to poor cooling and engine management, that they could melt. The pistons themselves could melt, possibly turning your inline-4 engine into an operational inline-3.

Subsequently, this issue could create rough idling, shuddering, as well as huge amounts of blow-by. Some have speculated on poor mapping with the ECM or fuel-air flow. This causes the engine to run lean (too much air, not enough fuel to burn). It’s exacerbated by the inclusion of the turbos, as the engine repeatedly goes in and out of boost, further adding heat and strain.

Other symptoms include seeing smoke from the engine, as well as burning oil (heavy oil use and consumption). Misfires can also happen, as you’ll notice a check engine light, on top of poor performance. The good news here is that this pre-ignition failure, which prompts a cracked or melted piston, isn’t as widespread. GM has identified the root cause to be the engine’s SPI system.

Or, ‘stochastic pre-ignition’. It can be easily fixed by heading over to a GM dealership and getting the engine control module (ECM) reprogrammed. According to a bulletin issued by GM to its dealerships, the motor oil should also be changed. They specifically name the ACDelco Dexos 1 full-synthetic oil. Alternatively, Mobil 1 oil for those affected cars sold in Canada.

Repair & Replacement Costs (Cracked & Melted Pistons)

• Estimated Repair Cost – Piston replacements require significant labor, with costs ranging from $3,000 – $6,000 depending on the severity. Unfortunately, if your engine needs a full rebuild, the cost could exceed $7,000 – $10,000, or more.
• Is It Covered by GM? – Some instances of this problem have been covered under the powertrain warranty if failure occurs early. However, GM has denied some claims, citing “driver operation” or “poor maintenance” as potential causes. So, it’s worth bearing that in mind.
• Related TSBs – TSB #19-NA-218 acknowledges pre-ignition damage and suggests reprogramming the ECU to adjust ignition timing. Alternatively, switching to Dexos 1 Gen 2 full-synthetic oil is also recommended as preventative maintenance.

Repair & Replacement Costs (High Temperatures & Blow-By)

• Estimated Repair Cost – If your PCV system is clogged, then repairs typically cost $200 – $600. However, if excessive blow-by leads to carbon buildup, then your engine cleaning services that cost around $300 – $800. Severe cases might even require internal repairs costing you $2,000+.
• Is It Covered by GM? – There hasn’t been any direct warranty coverage unless linked to a manufacturer defect. However, some emissions-related repairs might be covered under federally mandated emissions warranties, and it could fix this issue.
• Related TSBs – TSB #20-NA-047 highlights carbon buildup concerns. Here, GM advised owners to use Top Tier gasoline and follow shorter oil change intervals to reduce carbon deposit formation.

Worst Years To Avoid

GM’s 1.5 turbo inline-4 engine (LXV/LQC) has been widely used across various Chevy, GMC, and Buick models. While most of them can be quite reliable, some model years are more prone to issues than others. This could be due to inherent design flaws, faulty software tuning, or cold-weather performance challenges.

Based on our research, here are our findings for the most commonly affected GM models with 1.5 turbo engine problems, and some of the worst model years to avoid:

Problem Type	Affected Models	Most Affected Model Years	Frequency of Issue
Turbocharger Failure (Cold Weather)	Chevrolet Equinox, Malibu, GMC Terrain	2018 – 2021	High – Many drivers report failures, especially in colder climates.
Erratic Oil Pressure Readings	Chevrolet Equinox, GMC Terrain	2018 – 2022	Moderate – Many owners experience inconsistent oil pressure readings.
Frequent Check Engine Light (CEL) Activation	Chevrolet Malibu, Equinox, GMC Terrain, Buick Encore GX	2018 – 2023	Moderate – Sensors and ECU-related issues trigger the CEL.
Cracked or Melted Pistons (Pre-Ignition Issues)	Chevrolet Equinox, Malibu, GMC Terrain	2018 – 2021	High – Many engines suffer piston failure, often requiring a full rebuild.
High Engine Temperatures & Blow-By Issues	Chevrolet Equinox, GMC Terrain, Buick Encore GX	2019 – 2023	Moderate – Carbon buildup and PCV system flaws lead to excessive blow-by.

In summary:

• 2018 – 2021 Chevy Equinox & GMC Terrain models have the highest frequency of reported failures, especially the aforementioned turbo and piston issues.
• The Chevy Malibu (2018 – 2021) is particularly susceptible to oil pressure issues and pre-ignition piston damage.
• Newer GM models (2022+) show fewer complaints, but they still suffer oil pressure sensor issues and intermittent CEL activations.

GM SGE (Small Gasoline Engine) Specs & Features

So, what about this GM SGE engine family, then? At the turn of the 2010s, General Motors realized the design and built a new series of engines, made with efficiency in mind. Good MPG figures alone aren’t enough. Thus, their engine needed to also be decently performant, have lower emissions, and reduce the NVH to a minimum.

The latter stands for Noise, Vibrations, and Harshness, which defines the unpleasant or discomforting sounds and vibrations that you’ll experience while driving. With all that in mind, GM succeeded in creating a lightweight, modestly powerful, fuel-efficient, low-emissions, and easy-going engine to fit into their smaller and cheaper economy cars.

GM’s SGE is also marketed as part of their ‘Ecotec’ (or in some other markets, ‘Microtec’) engines. On top of that, General Motors also sells this engine to its Chinese partner, SAIC Motors. Where, SGEs can be found on SAIC-made cars, too. There are four distinct configurations that an SGE engine can have:

• 1.0-liter (999cc, 61.0-cubic inch), turbocharged inline-3
• 1.1-liter (1,118cc, 68.2-cubic inch), inline-3
• 1.4-liter (1,399cc, 85.4-cubic inch), turbocharged inline-4
• 1.5-liter (1,490cc, 90.9-cubic inch), turbocharged inline-4

To make it happen, GM engineered an abundance of new and innovative technologies into its SGE collection of engines. For instance, just two engine blocks make all the aforementioned configurations (and many other unique or specialized variations).. This encompasses their 3- and 4-cylinder versions, as noted earlier.

GM SGE Engine Trivia, Facts, & Details

• A key aspect of the SGE Ecotec engine is its modularity, allowing GM to readily interchange components if needed.. Hence, they all have the same 2.91-inch (74mm) bore, and 3.19-inch (81mm) bore spacing.
• The direct injection fuel rails are mounted with bushings onto the cylinder head and valve cover. This can aid in reducing the vibrations and loud ticking sounds from the injectors. Consequently, GM has claimed that its 1.0-liter SGE engine is 25% quieter than Ford’s similar 1.0-liter engine in the Fiesta.
• In addition, GM’s other attempts to reduce noise from this engine include using a bed-plate engine block. This helps to increase stiffness, thus reducing any rattling or loose sounds, and use a stiffened aluminum cam cover. Also, the inline-3 engines get a counter-rotation balancing shaft. Bolted onto the oil pump, it can further lower radiated noise, as well as let it idle more smoothly.
• All turbocharged SGE engines carry a Mitsubishi Heavy Industries one-stage, single-scroll turbo. These can spool up very rapidly, with around 90% of their peak torque arriving between 1,500 to 5,000 RPM. This is fairly low in the rev range. Plus, peak power is within the 5,600 to 6,000 RPM range. The engineers also installed the turbo close to the cylinders, able to dole out speedy torque and throttle response.
• The engine is made mostly out of aluminum (block and head) and uses a composite intake manifold. This is all in the name of saving as much weight as possible, and the SGE is overall a small and light motor. It only weighs 216 lbs (98kg) for the bigger 1.4-liter engine, which is 44 lbs (20kg) lighter than its predecessor.