Most Reported Buick LaCrosse Problems And How To Fix Them

The Buick LaCrosse is well-known for its comfort and reliability, but like any car, it has its share of common problems. Owners have reported recurring problems with the engine, electrical components, and cooling system across different model years. To quickly summarize, here’s a TL;DR on some of the many Buick LaCrosse problems that you need to look out for:

1. Check Engine Light Constantly Turning On – Caused by excessive carbon buildup, especially in second-gen models.
2. Headlights Intermittently Turning Off – Due to a faulty Headlight Driving Module (HDM) in first-gen models.
3. Door Lock Locking & Unlocking Problems – Stemming from faulty body control modules and door lock actuators.
4. Cooling System Leaks – Common in early models with the 3.8-liter V6 engine, often due to a worn intake manifold gasket.
5. Faulty Ignition Module – Causes random stalling, particularly in first-gen models.
6. “Reduced Engine Power” Warning Light – Occurs at around 60,000 miles, with unclear root causes.
7. Timing Chain Failure – A problem in second-gen models, often accompanied by check engine lights.
8. Air Conditioning Issues – Problems with cooling and defrosting across second- and third-gen models.

In this detailed guide, we’ll be looking at some of the most common Buick LaCrosse problems, their underlying causes, and potential fixes, too:

Buick LaCrosse Problems By Model Year

Over the past few years, Buick has garnered a pretty positive reputation for reliability, but does the LaCrosse have serious problems? Well, numerous recalls were issued by Buick over the years to settle sporadic issues with the LaCrosse. This included fixes for software issues with the powertrain, power seats, seat belts, suspension assembly, and airbags.

Moreover, of the many Buick LaCrosse problems that we mentioned earlier, some model years experienced more issues than others. From our research, here are some of the worst model years of the Buick LaCrosse to watch out for:

Problem	Most Affected Model Years
Check Engine Light & Carbon Buildup	2010–2013 (2nd Gen)
Headlights Intermittently Turning Off	2005–2009 (1st Gen)
Door Lock Malfunctions	2005–2009 (1st Gen)
Cooling System Leaks	2005–2008 (1st Gen, 3.8L V6)
Faulty Ignition Module & Stalling	2005–2007 (1st Gen)
“Reduced Engine Power” Warning Light	2010–2016 (2nd Gen)
Timing Chain Failure	2010–2013 (2nd Gen)
Air Conditioning Issues	2010–2019 (2nd & 3rd Gen)

From this handy table, here are our key takeaways:

• The first-generation Buick LaCrosse (2005–2009) had several electrical issues, including headlight failures, as well as faulty door locks.
• The second-generation LaCrosse (2010–2016) suffered from engine-related problems such as carbon buildup, timing chain failure, and reduced engine power.
• The third-generation LaCrosse (2017–2019) was generally more reliable, though some owners still reported air conditioning system failures.

Buick LaCrosse Problems #1 – Check Engine Light Turning On

This problem mostly plagues the second-generation LaCrosse. Owners with only around 25,000 miles on the clock report that their check engine light is constantly turning on. Some even report a burning smell coming from the car. The problem seems to stem from excessive carbon buildup. The latter is a persistent and systemic issue with this generation’s LaCrosse.

While carbon buildup is normal, especially in direct injection engines, the LaCrosse has excessive carbon buildup during cold starts. This causes the engine to misfire, which then triggers the check engine light. There seems to be no clear solution either. Owners report that GM dealers will try to replace a fuel module, which manages extracting fuel from the tank.

However, the check engine light quickly reappears after this solution. It’s not quite clear what the exact solution is. It seems replacing the spark plugs and fuel injectors will solve the issue, but it’ll appear again in about a year. This isn’t normal unless you’re doing over 50,000 miles in a year. The engines in this second-generation car were simply poorly designed.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – It ought to cost you around $300–$600 for professional intake valve cleaning, or around $50–$150 for DIY cleaning kits.
• DIY Feasibility – DIY repairs for this are possible, but it’s quite challenging. It requires intake system access and proper cleaning tools, which not all folks have.

On the bright side, there are preventive maintenance techniques that could help you reduce the risks of this problem appearing again:

• If possible, you should use high-quality top-tier gasoline to reduce carbon buildup.
• Alternatively, you can add fuel system cleaners like Techron every few thousand miles.
• Consider a walnut blasting service (every 60,000 miles) for direct-injected engines.

Buick LaCrosse Problems #2 – Headlights Intermittently Turning Off

The first-generation Buick LaCrosse had problems with its headlights intermittently going off on their own. Or sometimes, they just downright won’t turn on at all, specifically with their low-beam lights. The solution seems to be quite simple; an HDM (Headlight Driving Module) replacement for the Buick LaCrosse should do the trick.

Although GM acknowledges this problem, they haven’t made any recalls to fix this. Note that the HDM is responsible for managing and ensuring the operation of the headlights. This means you’ll have to pay out of pocket. But don’t worry, owners report that it’s no more than $30 to replace. While the low beam is affected, the high beams should work just fine.

This isn’t exactly a serious issue, but driving with high beams constantly may earn you a ticket. You may get away with a “fix-it” ticket which costs less than $100 to pay. But a moving violation ticket will cost you $160 and more points on your license. As such, it’s best to address the issue and replace the HDM now that you’re aware of it to avoid tickets.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – It would cost you between $200–$600 for replacing faulty wiring, relays, or the headlight control module.
• DIY Feasibility – A DIY repair for this is moderately difficult. Basic troubleshooting (checking fuses, relays) is DIY-friendly, but deeper electrical work may require a professional.

To reduce the chances of your headlights turning on and off randomly, here are some maintenance tips to help you:

• You should always inspect and clean headlight wiring connections periodically.
• In addition, consider using dielectric grease on headlight connectors to prevent corrosion.
• If flickering starts, then quickly replace relays and fuses before complete failure occurs.

Buick LaCrosse Problems #3 – Door Lock Locking & Unlocking Issues

This is another problem that also plagues the first-generation Buick LaCrosse. Owners report intermittent problems locking and unlocking their doors. Their cars would sometimes just randomly lock or, more terrifyingly, won’t unlock when they’re inside. Some owners even have to lock each door individually every single time they want to leave their car.

The problem stems from faulty body control modules and door lock actuators. When these fail, the LaCrosse will have trouble operating the door locks. Owners report that this problem occurs when they reach the 70,000-mile mark and can cost up to $500 to fix. Thankfully, if you’re handy enough, you could replace the door lock actuators yourself for cheaper.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – It should cost you around $200–$400 per door actuator replacement.
• DIY Feasibility – Trying to DIY a repair for this is moderately challenging. It requires removing the door panel, but it’s fairly straightforward with basic tools.

Equally, you could perform regular maintenance on your door actuators to reduce the chances of this problem appearing:

• You could start by regularly lubricating the door latch and locking mechanism.
• On that note, avoid using excessive force on manual door locks, as doing this can stress the actuators.
• If your door locks become sluggish, replace key fob batteries first before assuming actuator failure.

Buick LaCrosse Problems #4 – Cooling System Leaks

Some of the earlier model year Buick LaCrosse models had cooling system issues, where coolant would slowly leak from your car. This mostly impacted Buick LaCrosses that were fitted with the 3.8-liter V6 engine. Owners report that the coolant leak is very slow, and can take up to five months until the coolant level gets so low that the car overheats.

A slow leak of this kind can be very difficult to diagnose. The underlying fault of this problem likely stems from a worn-out intake manifold gasket. The intake manifold is a component that distributes airflow between the cylinders, and it has a gasket that connects it to the engine. When the gasket is worn, coolant can seep out, slowly reducing the coolant level over time.

And, this eventually causes your car to overheat. Owners of Buick LaCrosses report that this coolant problem went away after replacing the intake manifold gasket. This will cost somewhere between $250 – $350 to replace. Thankfully, this cooling system leakage issue was mostly solved by the time the second-generation Buick LaCrosse came out in 2010.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – Fixing this would cost you approximately $300–$1,000, depending on whether it’s a radiator, water pump, or hose issue.
• DIY Feasibility – The difficulty with fixing this issue varies. Replacing hoses can be quite DIY-friendly, but radiator and water pump repairs are far more complex.

As with the earlier Buick LaCrosse problems, performing regular maintenance could help mitigate some of these issues:

• You should flush and replace coolant every 5 years/100,000 miles (this is per GM’s recommendation).
• Elsewhere, make sure that you regularly inspect hoses and radiator connections for wear and tear.
• While you’re there, check for low coolant levels and any leaks under the car periodically.

Buick LaCrosse Problems #5 – Faulty Ignition Module

Some owners of the first-generation LaCrosse reported that their cars would stall while they were driving. This is pretty scary, as it’s incredibly dangerous for a car to suddenly shut off and stall while you’re driving. The underlying cause of this random stalling issue seems to stem from faulty ignition modules and ignition wires that shorted.

When the ignition module and/or wires fail, the ignition coil won’t be able to send power to the spark plugs. And, when the spark plugs aren’t getting power, they won’t be able to create a solid spark that ignites the fuel and air mixture in the engine. When this happens, your Buick LaCrosse’s engine will cease to operate. This is what causes the random stalling.

A new, replacement ignition module is usually around $350 to replace, while a set of new ignition cables for the LaCrosse is somewhere around $60. However, an owner reported that they had the ignition module and wires replaced at a Buick dealer, and it cost them around $900 to get the job done. So, it’d be a good idea to call up your dealer beforehand.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – It should cost you approximately $300–$700 for ignition module replacement.
• DIY Feasibility – Fixing this yourself, DIY-style, is possible, but it requires extensive knowledge of ignition system wiring.

With that in mind, preventive maintenance might help reduce the severity of this ignition issue with your Buick LaCrosse:

• Make sure that you replace spark plugs and ignition coils regularly to reduce ignition strain.
• Avoid using cheap aftermarket ignition modules. Always use OEM parts, as they last longer.
• Keep battery terminals clean to prevent voltage drops affecting ignition.

Buick LaCrosse Problems #6 – “Reduced Engine Power” Warning Light

One of the more prevalent issues with the Buick LaCrosse is a common engine problem that owners have reported: “Reduced Engine Power”. Owners report that they see a ‘Reduced Engine Power’ warning light turning on, at around 60,000 miles on average. After a while, the check engine light turns on as well. Reduced Engine Power is similar to limp mode.

This is where your car’s ECU (Engine Control Unit) decreases the power output and limits performance on purpose. This usually indicates a serious problem with your car’s engine or transmission, and the ECU is preventing further damage by reducing the engine’s workload. It’s not clear what the cause of the problem is, as owners seem to be facing different issues.

Some owners cleaned the throttle body and the problem went away, while others had to replace their fuel pump and sensor, and some others had to replace their accelerator pedal. It’s one of those flaws where it’s not quite clear what the root cause is, and GM isn’t admitting the problem. This makes life pretty difficult for owners keen on finding a permanent fix.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – Typically, this would cost you $400–$1,000, depending on the root cause (throttle body, wiring, or ECM issue).
• DIY Feasibility – Basic troubleshooting is DIY-friendly (cleaning throttle body, checking sensors), but deeper repairs may require a professional mechanic.

On the bright side, you could reduce the chances of this problem appearing, or at least reduce its severity on your car:

• Ensure that you clean the throttle body and mass airflow sensor (MAF) regularly, every 30,000 miles and 15,000 miles, respectively.
• Keep battery voltage stable (weak batteries can trigger reduced power mode).
• Additionally, update your engine control module (ECM) software, if one is available.

Buick LaCrosse Problems #7 – Timing Chain Failure

When the second-generation Buick LaCrosse was introduced, two common problems that owners experienced were timing chain failure and faulty throttle bodies. A bad timing chain can produce a loud rattling noise from the engine and trigger the check engine light (CEL). These are some early signs of failure. The throttle body sensor is also known to fail in the LaCrosse.

The sensors inside them can misalign and when they’re not in sync, they can trigger the check engine light and also cause performance issues. Speaking of, some of the earlier second-gen Buick LaCrosses had engine stalling and sudden shutoff problems, which didn’t really have a definitive and permanent fix. In addition, excessive carbon buildup remained.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – Being a more complicated repair job, it’ll cost you a whopping $1,500–$3,000 for a timing chain replacement.
• DIY Feasibility – Repairing this yourself is not recommended, unless you’re a professional. It requires extensive engine disassembly.

Thankfully, you could help your car by performing regular maintenance, including:

• Make sure that you change your engine oil every 5,000 miles to reduce timing chain wear.
• And while you’re doing that, use high-quality synthetic oil for better lubrication.
• It’s also a good idea to listen for rattling noises on startup. This is an early sign of chain tensioner failure.

Buick LaCrosse Problems #8 – Air Conditioning Issues

Throughout several model years of the Buick LaCrosse, across the second and third generations, in particular, owners have also reported air-conditioning problems. Owners report that the air-conditioning system in their LaCrosse isn’t working properly and that the defroster isn’t wide enough. This would be a problem if you live in either hot or cold areas.

It’s not quite clear what the cause of the problem is, but it’s usually a clogged expansion valve, a faulty compressor clutch, a bad AC compressor, a blown fuse, or possibly a Freon leak. The LaCrosse is more prone to experiencing these problems than other cars. This usually occurs at around 30,000 miles. AC repairs should generally cost $150 – $200.

Repair Costs & Preventive Maintenance

• Estimated Repair Cost – Fixing this could cost you around $500–$1,500 (depending on whether it’s a compressor, refrigerant leak, or blend door issue).
• DIY Feasibility – DIY repairs for this are quite limiting. Some repairs (like recharging refrigerant) are DIY-friendly, but compressor replacement requires a professional.

If you’re keen to reduce the chances of air-conditioning problems constantly appearing, here are some maintenance tips:

• Run the AC system for a few minutes every month (even in winter) to keep seals lubricated.
• Additionally, be sure to replace cabin air filters regularly to prevent airflow blockages.
• If the A/C cooling is weak, check for low refrigerant levels before assuming compressor failure.