Mini Merc

WISE BUYER

1996-2004 The R170 SLK is still very affordable, but it pays to choose your car carefully, says James Walshe

Why you want one

Now at the grand age of 30, this seductively styled two-seater with elegant electric folding hard–top and a Mercedes badge was launched to an eager public in 1996 and while based on a shortened W202 C-class, the SLK 230 ‘Kompressor’ was quite the showstopper. Its M111 supercharged DOHC four–cylinder engine was good for 193bhp and came with the folding hard–top that combines saloon–like security with a pleasing open–topped driving experience.

A February 2000 facelift brought with it body– coloured side skirts, a six–speed manual gearbox option and flatter cornering. All facelifted SLKs also have standard traction control, an improved ride and better seats. The smaller engined SLK 200 Kompressor launched in the same year was slightly less brisk than the 230K. Find an SLK 320 and you’ll have a smooth V6, which sounds terrific and works well with both six–speed manual and auto transmission. It isn’t much quicker than 230K, but the noise makes it worthwhile alone. If you want some extra oomph, seek out an SLK 32 AMG. This was launched to rival the Boxster S and BMW M Roadster and has a hand-built 349bhp V6 and many special AMG goodies, which transformed the SLK into a road rocket.

MARKET ANALYSIS

Thirty years since launch, examples of the early SLK are becoming thin on the ground. Most of the tatty, high-mileage bangers have gone but you might get lucky and find a reasonable car for £1000. It’ll cause a few headaches though – this is not a Mercedes that’s built like the older cars from Stuttgart. Models range from the supercharged 200 to the thunderous 354bhp 32 AMG, the latter of which is harder to find. It still won’t cost you the earth – Manor Park Classics saw a good 32 AMG sell for just five-and-a-half grand in May. You’ll pay a few grand more for the best though. The most we saw a 230 sell for recently was a very tidy 2003 model at Mathewsons, which went for £4623. Nevertheless, you can comfortably aim lower as the going rate appears to be between two and three grand.

The inspection

Most Mercedes of this generation will have exhibited varying degrees of corrosion problems by now. The question is how well – or otherwise – they have been repaired. On the R170 you should look closely at the rear arches – feel inside, especially if there are rust scabs visible from the outside. Front arches can bloom just as badly, as can the boot lid around the keyhole and – more seriously – the sills and floors. Walk away from anything with evidence of rot underneath but more judgement is required with resprayed cars.

Some SLKs will already have been repainted to correct cosmetic problems caused by rust. It’s vital to distinguish between a hasty wipe of filler and a blow-over, and a professional de-rusting and refinishing job. Photos of the process and a bill in the history file are encouraging, but look for overspray on light lenses, tyres, parts of the engine bay, trim or side-skirts. Look along each side of the car and check for dips, ripples and dull patches in the paint. Poorly repaired rust–spots will bubble up again in just months on an SLK.

The R170 may be cheap to buy, but it’s still a Mercedes and can be costly to service through a main dealer. An ‘A’ service is around £400 while the more involved ‘B’ service is nearer £800, though independents charge less than half this amount. Check which is due, and how soon, before you make an offer and decide if you’re happy to tackle maintenance yourself. There is plenty of help out there. Bear in mind that V6s have 12 spark plugs, which cost a whopping £16 each.

Comfy cabin can become shabby easily.

The most common problems on four–cylinder cars are clogged flame traps and damaged air–mass meters, which cause the engine management light to come on but may just show up as a lack of power. The air–mass meter (also known as mass air-flow or MAF sensor) can be cleaned or replaced as a relatively easy and inexpensive DIY job but to be sure there’s nothing more serious amiss, specialist garages can perform a diagnostic plug–in to reveal fault codes.

An engine that shakes when idling needs new mounts (£200 fitted) and not that hard to do yourself. Listen out for loud or continuous noises from a Kompressor’s supercharger – a good used item will cost you a few hundred quid or so.

Four-cylinder engines have a magnet that adjusts camshaft timing. Find it on the right of the front face of the cylinder head, held on with three hex– head bolts. Oil can leak from the head into the magnet, thence into the plug mounted on it and in bad cases all the way up the loom to the engine or gearbox ECU, finishing it off and landing you with a £1000 garage bill. Unclip the plug to the magnet and check for oil inside. Replacing the magnet and a revised, oil–proof portion of the loom called a starter line is good insurance and something you can do at home.

V6s have fewer vices, but the exhaust system features four catalytic converters in two pipes, which cost £400-£500 to replace. Misbehaviour from an automatic gearbox – being stuck in gear, for example – can often be traced to a failed speed sensor, faulty multi-pin connector or even something as simple as low transmission fluid.

Engines excellent, especially with supercharger.

Front lower balljoints fail, leading to clunks when negotiating bumps or potholes but they’re cheap to replace (at £40 each), while rear springs (from £150 per pair, fitted) have a habit of snapping off the bottom coil – feel for thumps and bangs from each corner of the car. A persistent squeak from the rear is more likely to be dried-out bushes. Alloy wheels blister and bubble, so get down on your hands and knees to check!

Inside the SLK, the large centre console suffers from peeling paint around the handbrake area and the top surface where the seatbelt buckles constantly abrade them. Handles and door cards are affected too. The plastic underneath is black – it’s not so much of a problem if the top paint is also black, but looks shabby and unpleasant on cars with grey, blue, red or especially cream interiors

The Vario Roof doesn’t take kindly to neglect. Troubles vary from stiff hinges and squeaky seals – both curable with a bit of DIY lubrication – to failed roof pumps, which cost £800 at a specialist, if you don’t fancy trying it yourself. Raise and lower the roof several times with the engine running and look for hesitation. It should go up and down smoothly in about 24 seconds. Both windows should lower automatically when the roof starts to open and rise again after the roof is closed.

Some problems are caused by failed microswitches in the roof and boot lid; there are nine in all and while it’s unusual for more than one to fail at once. The system uses small actuating cylinders in the roof, a pump concealed in the right–hand side of the boot and two rams that raise and lower the boot lid. Stains or droops in the headlining may be just down to water ingress but could also be signs of leaking cylinders. Damp boot carpets or signs of condensation are probably due to water ingress created by a blocked drain hole, which – thankfully – is easy to fix.

Headlamp plastic commonly fogs up

WHAT TO PAY

TECH SPEC

WHAT WE SAY THE ONE TO BUY

Danny Hopkins
Editor

The pictures we’ve used in this month’s Wise Buyer are of my old Mercedes-Benz SLK230 Kompressor – a car that I revived and put back on the road a few years ago. I have to say, I would go back to one of these in a shot. Small and nimble enough to be fun, while robust and comfortable enough to tour with ease. And fast-ish, too. The folding roof takes up a lot of space, but when it is up you feel like you are in a coupé. Oh, and it’s supercharged as well. So, actually, if I could have this car back I would. I wonder where it is now?

James Walshe
Deputy editor

I’d be looking to get the most naughty version available. When AMG had a crack at breathing new life into the Mercedes-Benz SLK, it released the car’s potential and took it to all-new heights of performance madness. While not as slick to drive as a Porsche Boxster S, the little Mercedes nevertheless had a huge amount of extra grunt, and the handling to match. It’s a real rarity today, yet not as daftly priced as you might imagine. Make sure your prospective purchase hasn’t been through a hedge though.

Matt Tomkins
Workshop editor

For me, intrigue lies in launch specification. It’s how the car first broke cover and made its presence felt. As such, I’ll seek out a SLK 230 ‘Kompressor’ with supercharged, DOHC four–cylinder engine, 193bhp and the folding hard–top ‘Vario Roof’. It’d have to be in that deliberately-bold Sunshine Yellow hue, too. Although most were autos, I’d be keeping my eyes peeled for a manual. I’m not a fan of a sports car deciding when I should be swapping cogs; it’s my job to get that wrong, thank you!

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