S550 Mustang GT Bad Years: Which Models to Avoid

S550 Mustang GT bad years mainly include 2015-2017 models, which experienced transmission issues, suspension problems, and electrical glitches. These issues affected performance and reliability, especially with the MT82 manual transmission and early 10-speed automatic.

The Ford Mustang is an iconic American muscle car known for its power, performance, and unmistakable design. The S550 Mustang, introduced in 2015, represents the sixth generation of the legendary pony car and brought with it a new level of sophistication and technology. From the 2.3-liter EcoBoost to the ferocious 5.0-liter GT, the S550 Mustang offers something for every performance enthusiast.

However, like any vehicle, the Mustang GT isn’t perfect, and certain model years are known to have recurring issues that should be considered when buying used.

In this article, we’ll explain the common problems that plague specific S550 Mustang GT model years, offering an in-depth look at which years you might want to avoid and why.

Contents

1 The S550 Mustang GT
2 Common Issues with S550 Mustang GT Models
3 How to Avoid S550 Mustang GT Problems
4 Frequently Asked Questions
5 Conclusion

The S550 Mustang GT

The S550 generation marked the first time the Mustang was equipped with an independent rear suspension (IRS) instead of a solid rear axle, drastically improving handling and ride quality. Along with this, Ford introduced a turbocharged four-cylinder EcoBoost engine, while maintaining the powerful V8 options that enthusiasts love.

The Mustang also featured modern technology such as improved infotainment systems, advanced safety features, and more refined interior quality. As a result, the S550 Mustang became a more comfortable, practical car that still maintained its aggressive performance reputation.

However, despite these advancements, the S550 Mustang also faced some teething issues, especially in the early years of production.

Common Issues with S550 Mustang GT Models

While the S550 Mustang GT has become known for its impressive performance and solid build quality, there are certain issues that have been more prevalent in specific model years. Let’s take a closer look at the common problems that have plagued certain model years of the S550 Mustang GT.

1. Transmission Problems in Early Models (2015-2017)

The transmission issues in the early S550 Mustang GT models, particularly from 2015 to 2017, were among the most commonly reported problems by owners. Understanding these transmission problems and their causes will help you identify potential issues in these models and take necessary precautions.

Why Transmission Issues Occurred

MT82 Transmission: The manual transmission used in the early S550 Mustang GT models, specifically the MT82, received significant complaints regarding its shifting performance. Drivers reported notchy shifts, difficult engagement, and grinding between gears. These issues were most common in the 2015-2017 models but were also seen in some early 2018 models.
10-Speed Automatic Transmission: The 10-speed automatic transmission that debuted in 2018, although largely an improvement, initially faced minor calibration issues. Some drivers noticed jerky shifts and delayed throttle responses, particularly in stop-and-go traffic. Ford addressed these issues through software updates, but the early models still had some drawbacks.

How to Identify Transmission Issues

Identifying transmission issues early on can help prevent more serious damage and costly repairs. Below are some common signs that your S550 Mustang GT may be experiencing transmission problems.

If you’re driving a 2015-2017 Mustang GT, pay attention to how smoothly the car shifts, especially when changing gears at higher RPMs.
Check for unusual noises such as grinding or clicking when the clutch is engaged or when shifting from first to second gear.
For 2018 models, it’s essential to test the transmission for smooth shifting and throttle response.

2. Suspension Issues and Ride Quality (2015-2017)

During the 2015 to 2017 production years, many owners reported problems with the suspension system and overall ride quality. Understanding these issues can help potential buyers identify early warning signs and ensure a smoother driving experience in these particular models.

Suspension Problems in Early Models

Rough Ride and Suspension Noises: One of the most common complaints about early S550 Mustangs, particularly the 2015-2017 models, was the harsh ride quality, especially with the optional sportier suspension setups. The independent rear suspension (IRS) offered better handling than the previous solid axle, but the overall ride quality left much to be desired, particularly on rough roads. Some drivers also reported suspension noise, including squeaking and clunking sounds during turns or bumps.
Bushing Wear: Many owners of 2015-2017 Mustangs experienced premature wear on suspension bushings, which led to an uncomfortable ride and handling issues. This problem is often linked to aggressive driving styles or low-quality factory parts that wore down faster than expected.

How to Identify Suspension Issues

Identifying suspension issues early is crucial for ensuring a smooth and safe driving experience. Below are some key signs and symptoms to watch for when diagnosing suspension problems in your S550 Mustang GT.

Listen for any unusual squeaking, clunking, or popping noises when driving over bumps or making sharp turns.
Test for abnormal handling or uneven tire wear, which may indicate problems with the suspension alignment.
Inspect the bushings for cracks or visible signs of wear if you own or are looking to buy a 2015-2017 model.

3. Electrical and Infotainment System Glitches (2015-2019)

Electrical and infotainment issues were some of the most frequently reported problems in the 2015-2019 S550 Mustang models. These glitches can affect everything from the car’s electrical systems to the responsiveness of the infotainment system, impacting the overall driving experience.

Sync 3 System Glitches: One of the more common issues in the early S550 Mustang models, particularly from 2015 to 2019, was related to the Ford Sync 3 infotainment system. Owners reported slow response times, freezing screens, and occasional system crashes. Some drivers even experienced Bluetooth connectivity problems with their phones, which disrupted audio playback and hands-free calls.
Battery Drain: A small number of S550 owners complained about battery drain issues, where the car’s electrical system continued to consume power even when the car was off. This problem was particularly prevalent in early models with the Sync 3 system and could lead to the car failing to start after a few days of inactivity.

How to Identify Electrical Issues

Test the infotainment system to check for responsiveness, lag, or crashes.
Look for issues with the radio, Bluetooth connectivity, or screen freezing.
Pay attention to any issues with the battery, such as it draining more quickly than expected.

4. Overheating and Cooling System Issues (2015-2017)

Overheating and cooling system issues were reported in several 2015-2017 S550 Mustang GT models, particularly under heavy driving conditions. These problems can lead to engine performance issues, so it’s essential to understand the symptoms and potential causes to prevent overheating and costly repairs.

Cooling Fan Failures: Some 2015-2017 Mustang GT owners reported issues with the cooling fans, particularly the fans not kicking in when the engine temperature rises. This caused overheating problems, especially during prolonged driving sessions or high-performance situations like track days.
Thermostat Failures: There were reports of thermostats failing in the early S550 models, which could lead to engine temperature fluctuations and even overheating. This issue was often exacerbated in warmer climates or when the car was driven hard.

How to Identify Cooling System Issues

Monitor your engine temperature during long drives or high-performance sessions.
Check for any unusual coolant leaks or smell of antifreeze.
If the engine temperature is consistently running hot, have the cooling system checked, including the thermostat and fans.

5. Fuel Economy and Turbo Issues (2015-2017 EcoBoost Models)

The 2015-2017 EcoBoost models of the S550 Mustang GT faced challenges with fuel economy and turbo performance. Understanding the underlying causes of these issues can help owners ensure the optimal operation of their turbocharged engines while maintaining better fuel efficiency.

Turbo Lag and Power Delivery: The EcoBoost 2.3L engine found in the early S550 Mustang models experienced some issues with turbo lag. While it offered impressive horsepower, some drivers complained about inconsistent power delivery, especially at low RPMs.
Fuel Economy Discrepancies: Some 2015-2017 EcoBoost models reported fuel economy issues, with real-world consumption often falling short of the advertised figures. This issue was mainly attributed to the early calibration of the turbocharged engine and fuel injection system.

How to Identify Fuel Economy Issues

Check the fuel efficiency against the manufacturer’s advertised numbers, and if you notice significant discrepancies, there may be an issue with the turbocharger or fuel system.
Test acceleration and throttle response to see if the car is sluggish or exhibits turbo lag.
Regularly check the fuel consumption and address any discrepancies through a diagnostic test.

Common Issues with S550 Mustang GT Models

How to Avoid S550 Mustang GT Problems

To avoid the common issues associated with certain S550 Mustang GT model years, regular preventative maintenance is essential. Here are a few tips:

Regular Transmission Maintenance: Ensure that your Mustang’s transmission fluid is checked and changed regularly. If you’re driving a 2015-2017 model with the MT82 manual transmission or a 2018 model with the 10-speed automatic, make sure the transmission is properly maintained.
Suspension Inspections: Perform regular suspension inspections to check for worn bushings or noisy components, especially if you have a 2015-2017 model.
Electrical System Checks: Keep your electrical and infotainment systems updated. Always ensure that your Sync 3 system is running the latest software.
Cooling System Maintenance: Have your cooling system inspected regularly to prevent overheating issues, especially if you drive in warmer climates or push your car to its limits on the track.
Fuel System and Turbo Maintenance: For EcoBoost owners, regular turbo and fuel system checks are important to ensure consistent power delivery and optimal fuel efficiency.

Frequently Asked Questions

Here are some FAQs about S550 Mustang GT bad years –

1. Which S550 Mustang GT model years are most reliable?

The 2017 and 2019 models are generally considered the most reliable, with improvements made to the transmission and suspension systems.

2. Are transmission problems common in all S550 models?

Transmission issues were particularly prevalent in the 2015-2017 models, especially with the MT82 manual transmission and early 10-speed automatic.

3. How do I maintain my S550 Mustang GT’s transmission?

Regularly check the transmission fluid, address any shifting issues immediately, and ensure the vehicle is driven appropriately to avoid overuse.

4. What are the most common issues with the EcoBoost engine in the S550?

Turbo lag and fuel economy discrepancies were the most common issues with the EcoBoost engine, particularly in 2015-2017 models.

5. How can I ensure my Mustang GT doesn’t have suspension problems?

Have the suspension components regularly inspected, and replace any worn bushings or noisy parts to maintain optimal performance.

Conclusion

The S550 Mustang GT is an iconic vehicle that combines performance, style, and modern technology. However, as with any car, certain model years have experienced more problems than others. By being aware of the common issues associated with specific model years, you can make a more informed decision when buying a used Mustang GT.

Whether it’s transmission issues, suspension problems, electrical glitches, or fuel system concerns, knowing what to look for will help you avoid costly repairs and enjoy the Mustang to its fullest.