Mercedes-Benz Coupe Range

Any second-hand car can give you problems, and this era of Mercedes-Benz production was not exactly notable for its build quality or reliability. On the other hand, that’s an insanely small amount of money for a convertible with a Mercedes-Benz badge, isn’t it?

The first thing to check is the overall condition. You say it’s a 7 out of 10 car, so presumably it’s showing its age in a few areas. Make sure everything electrical works properly and don’t forget things like the air-conditioning and cruise-control, both of which can cost a bomb to put right. Make extra sure the convertible roof works as it should, and check for wind noise from the roof at speed which could indicate an alignment problem. These roofs can easily be knocked out of whack in a rear end or side-on crash, so it’s vital everything lines up. The service record is crucial in a car like this, too. If there’s evidence of skipped maintenance, think long and hard about the purchase. These cars are complex and won’t tolerate sloppy servicing.

So why are cars like his so cheap? Mainly because people are scared that any repairs or parts needed will cost the earth. And there’s a fair bit to justify those concerns. Even apparently simple things like the dashboard vents are often complex, vacuum operated horrors in this era of European luxury cars, and can destroy your household budget to repair. But if you can set aside some money for repairs, and you are prepared to walk away from the thing if it all gets too hard (and expensive) then there’s a lot to like about a second-hand luxury car. Especially one that cost about $120,000km on the road when brand new and is now available for a fraction of that.

Traditionally, Mercedes-Benz has taken the entirely logical step of printing a legend of the fuses and what circuits they relate to on the inside of the fuse box cover. By referencing this, you can quickly identify what each fuse does while you’re in there checking whether they’re blown or not.

For some reason, however, sometimes Mercedes placed a paper diagram of the fuse layout in the boot with the jack and tools. So check there as well. The owner’s manual should also offer this information in the electrical section. If none of that works, you can Google the make and model and ask for fuse box information.

Don’t forget, either, that there are often two fuse boxes in many modern cars; one under the bonnet and one under the dashboard or inside the glovebox.

Colleagues of mine have noted that the C43 isn’t at its happiest when taking off from a standing start sometimes, particularly if the stop-start function is engaged. That said, the harshest description of the problem was the odd clunk when launching the car, but even with that system switched off, the AMG sometimes seems to have problems deciding which gear to select, leading to a lack of smoothness. Perhaps it’s not helped by the fact that the car is all-wheel-drive, and grips the road extremely well when perhaps a little `give’ in the driveline mightn’t be a bad thing. Maybe it’s the traction-control stepping in too early and interrupting the flow of power to the wheels.

That said, your problem sounds a lot more severe than that. The C43 uses a conventional torque converter automatic transmission, so it doesn’t suffer some of the jerkiness that other cars using dual-clutch technology can. It’s puzzling though, that the computer isn’t throwing up any fault codes, so maybe your car is simply doing what some C43s do to a greater or lesser extent. If it’s as bad as you say, it’s not good enough and you should pursue the problem with Mercedes-Benz and have the problem corrected under warranty.