GM’s LFX engine was released in model year 2012 as a replacement to the LLT engine. The LFX is a direct-injected 3.6L V6 engine producing 301-323hp and 262-278lb-ft. of torque.
Its predecessor, the LLT was released in 2006 in various GM cars. The LFX debuted in the Chevy Camaro LS and received an updated cylinder head with integrated exhaust manifold, new fuel injectors, intake valves, fuel pump, along with a new intake manifold. The LFX engine is 20lbs lighter than the LLT, 11hp and 5lb-ft. of torque more than the LLT at the top end. With an increased compression ratio of 11.5:1, the LFX is also E85 compatible.
By 2017 the LFX was predominantly phased out although it lasted until 2020 in the Chevy Impala. The LFX was phased out in favor of the LGX which launched in 2016 and is still used today. Also a direct-injected engine, the LGX was increased slightly in size with larger bores and intake and exhaust valves. It additionally received an upgraded cylinder head and higher RPMs, increasing power levels up to 335hp and 285lb-ft. of torque.
Cars that use the GM LFX Engine
In addition to the below models, the LFX was also used in various Holden models in Australia such as the Caprice and Commodore.
- 2012-2016 LaCrosse
- 2013-2015 ATS
- 2012-2015 CTS
- 2012-2016 SRX
- 2013-2019 XTS
- 2012-2015 Camaro
- 2012-2017 Caprice
- 2015-2016 Colorado
- 2013-2017 Equinox
- 2012-2020 Impala
- 2015-2016 Canyon
- 2013-2017 Terrain
LFX Engine Problems
- Excessive Oil Consumption
- Water Pump Failure
- Front Cover Oil Leaks (Timing Chain Cover)
- Timing Chain Failure (mostly LLT engines)
1. Excessive Oil Consumption
The LFX engine is known to consume up to 1 quart of oil for every 2,000 miles. While GM claims this is normal consumption, problems are caused by the engines oil change intervals. The “change engine oil” light on the LFX is computer-calculated and generally appears every 8,000-12,000 miles.
The issue that arises is that at 1 quart per 2,000 miles the engine becomes very low on oil before the change engine oil light appears. While the low engine oil light may still appear prior to this, it is very common for drivers to find themselves low on oil in between oil changes.
When oil runs low on these engines, the cam phasers are the first component to be deprived of oil. When the phasers are not being properly lubricated the result is poor engine timing which can lead to cylinder misfires and codes being thrown for the camshaft sensor.
Additionally, the timing chain is the second component to become deprived of oil. Excess oil consumption resulting in low oil levels are a common cause of timing chain failure as mentioned above.
LFX Oil Consumption Symptoms
- Low engine oil light
- Losing 1 quart of oil every 2,000 miles or more
- Camshaft sensor engine code
- Timing chain failure
How to Prevent or Fix Oil Consumption
Unfortunately, the engine oil consumption is considered normal in these engines. The excess oil consumption is less of the problem however. The problem is people not checking oil levels and continuing to drive on low oil levels. If you follow GM’s recommend oil change intervals and wait 8,000+ miles for an oil change, you need to make sure you top off the oil in between changes.
For cars with OLM (oil life monitoring), GM did recall this item to recalibrate the system to suggest earlier oil changes. If you haven’t had this performed we would recommend doing so to prevent low oil levels.
While we recommend still changing the oil every 5,000 miles, you can alternatively keep an extra quart or two of oil in your trunk and top it off every few thousand miles.
GM does have an oil supply kit that will keep the cam phasers and timing chain adequately lubricated, but it requires about 15 hours of labor to install. Maybe this is an option if you still have some warranty left but otherwise the cost of adding the oil supply kit is not worth the benefit. Just make sure you keep your oil levels topped off.
2. LFX Water Pump Failure
Water pumps circulate coolant throughout the engine. They are the primary system responsible for keeping engine temperatures within spec. The internal components of a water pump are subject to high pressures. The internal pressure naturally causes the internal components of the water pump and the gasket and seals to wear down over time.
As the internal components begin to wear down, the pump has to work harder to maintain adequate coolant flow. Additionally, gasket or seal leaks cause pressure drops within the system again requiring the water pump to have to overwork itself.
On the LFX engine the water pump is known to go out around the 80,000-100,000 mile range. Fortunately, there are warning signs of a failing water pump and you can catch it before the pump completely fails and overheats the engine. The LFX water pump has a “weep” hole which is a small drain hole on it. When the water pump starts to leak internally, coolant will drip out of the weep hole which is a telltale sign that the water pump is on its way out.
LFX Water Pump Failure Symptoms
- Coolant leaks onto underside of engine
- Engine overheating (water pump has already failed)
- Whining noise from engine
If you are overheating then the water pump has already failed. If you find small amounts of coolant leaks around the engine then the water pump is likely on its way out, but not completely gone yet.
We recommend replacing the water pump once you notice coolant leaks to prevent overheating. Overheating can toast head gaskets, internals, etc. and lead to numerous other problems if not addressed promptly. A dealership is probably going to quote you near $1,000 for a water pump replacement on the LFX. However, the parts themselves should be around $100 and it can be DIY’d in a few hours.
3. LFX Timing Chain Cover Leaks
The timing chain cover, also commonly referred to as the “front cover” protects and lubricates the timing chain. The cover bolts directly up to the front of the engine block and prevents the timing chain from being exposed to road dirt and debris and helps prevent it from coming loose off of its gears. However, the most important purpose of the cover is to help lubricate the timing chain with engine oil.
The LFX uses a timing chain instead of a timing belt, and therefore has a metal front cover. The cover is bolted up to the block with a gasket between the two. Because the gasket sits right up on the engine block it is subject to a lot of heat. Over time this heat wears down on the gasket and causes oil to leak out of the front cover.
The gasket also seals the engine pressure or vacuum. A failed gasket will not only leak oil but will also leak air and engine pressure which can result in various performance related issues.
Symptoms of a Failing LFX Timing Cover Gasket
- Oil leaking from timing cover (block/cover have noticeable oil on them)
- Low engine oil light or excess oil consumption
- Engine runs poorly, bad performance
- Knock sounds from engine
- Engine code for vacuum leaks, AFR issues, etc.
- P0016, P0017, P0018, P0019 (usually associated with chain failure)
While it is possible to crack a timing chain cover, most of the issues with the LFX arise from gasket failure. When the gasket fails it is important to replace it immediately as it can cause performance issues but can also result in low oil levels which can further damage the timing chain and engine internals.
Gaskets are relatively cheap but the
4. LLT & LFX Timing Chain Failure
Most timing chain issues are caused by low oil levels. As mentioned with the excessive oil consumption problem, low oil levels are commonly caused by the oil change monitoring system recommending oil changes too infrequently. When oil levels become low, the timing chain is one of the first components to be starved of oil. When this happens, the timing chains aren’t receiving enough lubrication and the temperature of the chains metal increases from the increased friction. As timing chain metal temps increase the chains stretch and can jump teeth on the gears.
Additionally, the timing chain tensioner worsens the problem. The tensioner is responsible for keeping the proper amount of tension in the chain so that it does not become loose and jump gears. The tensioner is hydraulically-actuated meaning it uses oil pressure to function. When the engine is low on oil, the tensioner does not receive enough oil pressure to keep enough tension in the chain, causing it to become loose.
The lack of lubrication can also cause the timing chain guides to wear down and need to be replaced too.
Is timing chain failure an LFX problem?
These timing chain problems were mostly associated with the LLT engine from 2007-2011. However, they also affected the 2012 models of the SRX, Camaro, and Impala. In April 2012, the timing chains received an upgrade which minimized the problems going forward.
With that being said, timing chains are maintenance items and can still fail over time. While they are known to fail as early as 30,000 miles on the affected 2007-2012 models, they should last closer to 150,000 miles on later model years without these issues.
For cars with oil life monitoring, GM did recall and recalibrate the OLM monitoring systems to prevent the extremely length oil change services and reduce the likelihood of running low on oil.
LLT & LFX Timing Chain Failure Symptoms
- Various engine codes
- P0008, P0009, P0016, P0017, P0018, P0019
- Poor engine timing
- Engine runs poorly, idles poorly, etc.
- Cylinder misfires
- Metal shavings in oil
When a timing chain fails, it throws the engines timing out of whack. If your timing chain completely falls off or jumps too many teeth it is extremely important to not turn the engine on. Running the engine with extremely poor timing can cause the valves to collide with the pistons causing serious internal engine damage.
LFX Engine Reliability
The LLT engine got a bad rap for reliability primarily because of the commonality of timing chain failure. Fortunately, this issue was addressed for most LFX engines and cars with OLM were recalibrated to prevent low oil levels.
The 2012 LFX models are going to be less reliable than 2013+ models as it suffered from the old timing chain issues. However, this problem is really only a problem if you let your oil levels run too low. Since the LFX is known to normally consume 1 quart every ~2,000 miles or so, we recommend either topping off oil in between changes or changing your oil more frequently.
While GM says service intervals in the 8,000-12,000 mile range are acceptable, we recommend changing the oil more frequently than that especially if you don’t drive that many miles yearly.
Outside of problems that can be caused by running low on oil, the LFX doesn’t have any catastrophic engine problems and has proven to be reliable. If you own or are planning on owning an LFX just be aware of the oil consumption issues and make sure you check your oil levels frequently to make sure they don’t get too low.
If oil levels are properly maintained, the LFX engine shouldn’t have any problem reaching the 200k mile mark. Just understand that by the time you reach these mileage levels there is likely a handful of maintenance items that will have arose like water pumps, hoses, timing chains, sensors, etc.
Let us know about your experience with the LFX engine in the comments.