Currently reading: Used car buying guide: Mercedes SLK 55 AMG
From the roar of its V8 to its long-nosed looks, there are plenty of reasons to shoot for a used SLK
John Evans
News
5 mins read
6 January 2020

You can tell a lot about a car from its seller’s flower beds. Take the 2005-reg SLK 55 AMG with 90,000 miles on the clock that we found advertised for £13,995. It’s a private-sale example and is photographed on the owner’s immaculate driveway, bordered with neatly trimmed bushes punctuated by flowering shrubs.

So the seller is house proud. It’s no surprise, therefore, to find they’re car proud, too, as their ad reveals: “Always run on Mobil 1 and V-Power. All 16 spark plugs recently changed. Fully stamped service book (next service is a minor). Vario roof works properly with all seals regularly treated with Gummi Pflege.”

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As a buying guide to the SLK 55, this ad doesn’t get much better, especially so since the seller reveals his car has had a new gearbox valve body, new engine mounts, new front wishbones, new chassis bushes and new rear shocks. We know the 55 is a heavy car and the front suspension takes a pounding, which could explain the wishbones, and we know, too, that engine mount failure is a risk with big motors. Leaky dampers and broken rear springs are an issue with all R171-series SLKs. The seven-speed gearbox is not a blameless unit, so the new valve body isn’t a surprise.

It sounds extremely tempting, especially since 2005-reg 55s attract lower road tax than later cars and have better front brakes than 2008-reg facelift models. Those brakes are expensive, though, which is why the seller of the example we found has made a point of saying his car’s are in good condition.

The SLK 55 AMG was launched in 2004, powered by a naturally aspirated 5.4-litre V8, producing 355bhp and driving the rear wheels through a seven-speed automatic gearbox with paddle shifts. An AMG bodykit, 18in alloy wheels, lowered suspension and quad exhausts were standard. Desirable options included a Harman Kardon stereo and Airscarf neck heating.

Another was the £4500 AMG Performance pack, featuring composite brakes, firmer suspension, split-rim alloys and a raised speed limiter (from 155mph to 174mph).

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Two years later, in 2006, the hardcore Black Edition arrived with 394bhp. In addition to its wider wheel arches, adjustable dampers, dual-mode gearbox, front strut brace, buckets seats and boot spoiler, it got a carbonfibre fixed roof that yielded a 45kg weight reduction. Mercedes expected to sell no more than 100 worldwide and you’re unlikely to fall over one today. That said, we found a 2007-reg example with 26,000 miles and full Mercedes-Benz service history for £27,971.

The facelift came in 2008, two years before production ceased. Visual clues are the restyled front bumper, side air vents and darkened headlights, while under the skin the model gained a quicker gearshift and a new variable steering system.

A Porsche Boxster S is a sharper drive but fire up a 55’s V8 and you’ll be hooked.

How to get one in your garage

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An expert's view

Colin Jackson, founder and MD, P3 AMG: “I’ve owned two SLK 55s. An abiding memory is being on the Modball Rally, driving on the Stelvio Pass and chasing a mate who was in a Gallardo. I had the gearbox in manual mode, on the paddles all the way. Great fun. After 1500 miles of solid driving across the Continent, I got out fresh as a daisy. It’s the 55’s exhaust note I love most. But the car’s comfortable, too, and so drivable. They’re meant to be quite rare but we get a few in the workshop. As long as it’s properly serviced, the engine is rock solid. The front suspension can get tired from the weight of the engine and the brakes take a hammering. I’d have another, though – no question.”

Buyer beware...

■ Engine: Scrutinise service invoices for work beyond routine oil changes. There are 16 spark plugs so check they aren’t due to be replaced. Breather hoses either side of the rocker covers are prone to coking up, causing uneven idling. Look for oil leaks from the cover gaskets.

■ Gearbox: Fluid requires changing every 40,000 miles. A low fluid level will cause overheating and clutch burn. Cycle through the gears, checking for smooth and noise-free engagement.

■ Brakes and suspension: Inspect discs and pads carefully as replacements are very expensive, especially so on pre-facelift versions, with their larger Brembo six-pot floating discs at the front and four-pots at the rear. The heavy engine can cause the front suspension arms to wear, upsetting the handling. Bushes and shock absorbers all take a hammering.

■ Body: Any corrosion is likely to be repair related, although on the underside, the rear subframes on some cars are showing signs of heavy corrosion, an MOT failure. Look for water ingress behind the seats and under the spare wheel. It enters via the compressed boot seal. Check the roof operates smoothly. Lack of use can cause the micro-switches to clog with dust.

■ Interior: Make sure the heated seats work. Kneeling on the bases can rupture the heating elements. It’s a common problem and expensive to put right. If fitted, check that the optional – and desirable – Airscarf system works. Ensure all warning lights illuminate on start-up and then go out.

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Also worth knowing

Despite emitting the same 288g/km CO2, annual road tax for SLK 55s registered before 23 March 2006 is currently £325 compared with £570 for those registered after that date.

How much to spend

£8000-£10,999: Small selection of high-mileage 55s, some of them repaired write-offs.

£11,000-£13,999: Mainly 2005-reg, most with high mileages but some 60,000-mile cars. Multiple previous keepers and some with excellent histories, although none with full Mercedes service history.

£14,000-£16,999: Excellent examples here, including a private-sale 2005-reg car with 60,000 miles and full Mercedes service history for £14,995. Also, some 2008-reg cars with full history for £15,500.

£17,000-£20,000: The best cars, including Mercedes approved used examples.

One we found

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SLK 55 AMG, 2005/05, 55,000 miles, £12,995: Tidy-looking low-mileage car with a good spec. Service history is a mix of main and specialist garages but is not described as full, which is a concern and may explain the price. For example, elsewhere, a 2008 car with 70k miles and full Merc service history is £15,500.

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