We know that a convertible is a tough purchase to justify for most Ontario drivers. The long, cold winters in much of the province make the idea of open-top driving unappealing for at least half the year, heated seats and steering wheels notwithstanding.
And yet, for the right driver, there’s an undeniable appeal in looking forward to the first opportunity you get to put the top down on a sunny spring day.
European automakers build some of the most desirable convertibles on the market, including a number of two-seat models, commonly known as roadsters. Buying a used luxury roadster can be intimidating, thanks to the potential for high maintenance and repair costs. Those costs can be managed, though, if you know what to watch for in a used model.
In this article, we’ll take a look at some of the common issues that affect used upscale roadster models from some of Europe’s best-known car companies. We’ve chosen the 2010 model year as a starting point, but some of the tips included below will also apply to older models.
Mercedes-Benz introduced what would be the final generation of its compact SLK roadster in 2011. A 2015 styling update also brought a new SLC name. All Mercedes-Benz SLK and SLC models have a folding hard roof.
Shortly after the 2011 SLK went on sale, Mercedes-Benz issued a service bulletin to help its dealers fix misaligned folding roof panels.
- The V8 that powers the high-performance SLK 55 model is known for burning oil. Mercedes says it’s normal for the engine to burn nearly a litre of it every 1,000 km of driving, or more if you frequently drive at high engine speeds.
- There’s not a lot of other information on the web about specific issues to watch for in a used Mercedes-Benz SLK or SLC. Still, there are many things you should check up on before buying.
- With the car parked, explore the COMAND infotainment system using the dial on the console. Make sure it responds promptly to your commands. If the car you’re testing has navigation, try entering a few different addresses to make sure the software can find locations. Then try following the system’s directions to see if they’re accurate.
- Try to connect your phone the car’s Bluetooth system. If it won’t connect, or drops the connection, the car could be due for a software update. Some Bluetooth systems don’t play well with phones that are significantly older or newer than the car.
- Make sure the climate-control system works as it should. It should react almost immediately when you change the temperature or adjust which vents you want air to come from. Some SLK models will have Mercedes-Benz’s air scarf system. This directs air to vents in the headrests designed to keep your neck warm.
Audi TT Roadster
Audi has been building its stylish TT for more than 20 years, during which time it has become a car-design icon. The second-generation model was in the middle of its run at our 2010 model year starting point. Audi introduced a third-generation TT as a 2016 model.
- The TT’s 2.0L turbo four-cylinder engine has a timing chain to drive the valves. That chain is designed to last a long time, but it will wear out. If you’re looking at a TT with a higher odometer reading, have a mechanic check that the chain is in good shape. As it wears, it will stretch and throw the valves out of time. Initially, this can just lead to poor performance, but a severely worn/stretched chain can cause major engine damage. A check engine light will tip you off if the valve timing is already out of sync.
- Another engine-related issue is carbon deposits on the intake valves. This is a common problem in engines with direct fuel injection. Advanced build-up of deposits can affect performance and trigger a check engine light. The deposits can be cleaned away, but it’s a job best left to a professional.
- The TT’s optional automatic transmission is a dual-clutch type. If you hear a clattering noise with the car idling and the transmission in neutral, the car may need a new flywheel. A juddering sensation when the transmission shifts gears indicates worn clutches. A metallic sound when driving is a sign of worn bearings in the transmission. Finally, an automatic TT that won’t start may have a faulty park/neutral safety switch, which prevents the engine from starting when the car is in gear. If the car won’t shift into reverse, or shifts into neutral while driving, the transmission may have a failed mechatronic unit.
- An Audi TT whose automatic transmission is in good shape should shift quite smoothly. If shift quality is poor, a software update may improve its performance.
The BMW Z4 succeeded the Z3 in 2002 with a more substantial appearance and fussier styling. For this article, we’re looking at the second-generation Z4, which arrived in 2009 with a dramatic look and a standard folding metal roof.
- BMW Z4 reliability issues include problems with its turbocharged engines. The optional turbocharged six-cylinder uses a failure-prone high-pressure pump. Symptoms to watch for include long cranking times at start-up and/or the presence of a check engine light in the gauge cluster. This engine is quite powerful; if the car’s performance seems lacking, that could also point to a bad pump.
- In 2012, BMW added a turbocharged four-cylinder engine to replace an older six-cylinder. It is the subject of a class action lawsuit filed in 2017, after many BMW owners experienced engine failures related to stretched timing chains.
- The Z4’s optional automatic transmission is a dual-clutch type that is known for oil leaks.
- Many owners have complained of cracked wheels on the Z4, a problem that prompted its own lawsuit.
Britain’s Jaguar introduced the F-Type in 2014 as a coupe and convertible. It’s a well-executed sports car offered with a wide range of engines and performance levels. Depending on the model year, engines include a turbocharged four-cylinder and supercharged V6 and V8 power plants. Jaguar offered later models with all-wheel drive.
- The most common F-Type complaints include automatic-transmission shifting problems and convertible-top faults. As with many modern cars, the F-Type is sensitive to a weak battery, which is frequently to blame for both of those issues. Before getting too deep into diagnosing a mechanical problem, replace the battery. If that doesn’t fix the issue, then it’s time to start troubleshooting.
- When shopping for a used F-Type, check the engine coolant level. If it’s low, suspect a leak from the water pump or somewhere else in the cooling system’s plumbing.
- Some owners report the Jaguar F-Type’s Bluetooth hands-free telephone system doesn’t work well with certain smartphones. In some cases, updating the car’s software will fix connectivity problems. In any event, take some time during your test drive to see if your device will pair with the car.
Porsche introduced the third-generation Boxster in 2012 and redesigned the car again in 2016. The newer model is called the 718 Boxster, the number referring to a successful Porsche racecar of the late 1950s.
- If you choose a Boxster with the optional dual-clutch automatic transmission, be aware it is sensitive to low battery voltage. An “emergency transmission run” warning in the gauge cluster may be accompanied by a transmission that won’t shift out of neutral. This is very often caused by a weak battery and does not necessarily point to a mechanical transmission fault.
- A Boxster engine that runs rough and is accompanied by a foreboding “engine failure” warning can be caused by a failed ignition coil. It’s a common problem in these cars, regardless of the model year.
- If your Boxster displays any kind of fault message, don’t try to “fix” it by disconnecting and reconnecting the battery. Ignoring a potential problem could result in very expensive damage.
- Boxster models from the 2008 model year or before have a well-known bearing flaw in a shaft that powers the oil pump and camshaft chains. If it fails, the valves can fall out of sync with rest of the engine and lead to very serious damage. A badly worn bearing makes a rattling noise we’ve seen described as “obnoxious.”
Roadster convertible roof mechanisms
All of the cars we discuss here have electric convertible roof mechanisms. During your test drive, raise and lower the roof several times to make sure it works properly. It should move smoothly and finish its operation in about 30 seconds, or less in some cases. Some cars require you to hold the button or switch until the roof is locked in place; in others, you only have to touch the button briefly and the car will do the rest.
- It’s normal for the roof mechanism to make a whirring sound as it works. Listen for clunking or grinding sounds, which could indicate worn or damaged components.
- Once the top is open or closed, the car will probably flash a message saying the roof is locked in place. Watch for any other warning messages while the top is moving. If the roof stops partway, that’s usually a sign that something is wrong.
- During your test drive, put the roof up and take the car through a high-pressure car wash to look for leaks. A few drips of water from around the door windows is okay; more significant amounts of water could indicate damaged weather stripping or seals between hard roof panels.
Fabric tops versus a folding metal roof
Depending on which car you look at, it will either have a traditional fabric roof or a metal roof that splits and folds away. Both present unique ownership challenges.
- A fabric roof can crack and tear as it ages, allowing water and wind into the cabin. Some manufacturers recommend against operating a fabric roof in cold temperatures, which can make the roof material brittle and prone to damage.
- If you want to open a folding metal roof in winter, make sure it’s clear of snow and ice, which can get jammed in the mechanism.
Regardless of which model you’re test driving, spend some time using the infotainment system. Some operate via a touch-sensitive screen, and others respond to a dial on the console. Explore all of the system’s menus, watching for slow response times or system crashes.
Most modern vehicles are sensitive to low voltage levels caused by a weak battery. Even if the battery has enough power to start the car, it could cause problems as varied as poor transmission performance and infotainment system bugs. If anything is wonky during your test drive, a new battery may be all the car needs.
Pay for a pre-purchase inspection
Before you buy, ask the seller if you can get the car inspected by a mechanic of your choosing. With high-end models like the ones we’re discussing here, your best bet is a franchised dealer service department associated with the company that made the car. An experienced dealer technician will be familiar with known problems and their most effective fixes.
Franchised used-vehicle dealers offer certified pre-owned (CPO) vehicles that usually come with warranty coverage beyond what may be left of the factory warranty. These manufacturer-sponsored certified programs usually promise an extensive reconditioning process that makes CPO cars attractive prospects.