Why the £6000 difference? There’s the seller’s margin, of course, but the fact is that an auction, the basis of this valuation, is no place for a specialist vehicle such as an SL55. Down among the workaday Mondeos and in front of steely traders, it just looks like a money pit, and the valuation reflects that. Still, it’s a sobering exercise and shows why, when buying one, you should have your dealing boots firmly laced up.
Deal done, you’re in for a treat. Under that beautifully crafted aluminium body lurks a true supercar. AMG took the V8 from the SL500 and strengthened it in almost all areas to cope with the 55’s extra power, which is sent aft via a robust five-speed auto with paddle shifts. Some of that extra power came from mechanical changes, including an increased capacity, a faster-spinning supercharger and computercontrolled engine mapping.
The Active Body Control (ABC) suspension system serves up a firm but comfortable ride but it can leak and cause the pump to fail, expensively. The vario-roof should have turned the SL55 into a true all-weather express but for the fact that the seals on early models can let water into the boot, where it shorts the motor. Cars from 2006 had better sealing and you can upgrade earlier roofs. Those 2006 cars also got slightly more power courtesy of a faster-spinning supercharger and a larger throttle valve. Emissions fell, too, but road tax is still £535.
When it was launched, demand for the SL55 comfortably outstripped supply. For good examples, the same holds true today. Just remember to haggle – and haggle hard.
An expert’s view...
PAUL THOMPSON, MERCEDES-BENZ CLUB
“I bought my SL55 new in 2002. It has done 67,000 miles and, apart from needing new front struts, has never put a foot wrong. It’s not leaked at the roof but I know early ones are prone. Allowing the drain holes to get blocked with debris doesn’t help. If you’re looking at an SL55 for under £20,000, be very careful and have it inspected by an expert. Your ‘One we found’ looks interesting but I’d rather it was a private sale so you can gauge the owner.”
Mercedes SL55 AMG problems...
Check the supercharger’s separate cooler isn’t leaking. There’s a lot of plumbing around the engine so ensure everything is fluid-tight and rust-free.
Variable but usually every 12k miles. Brake fluid every two years, coolant every four, transmission oil/filter five.
The SL55 is an auto electrician’s nightmare. Known weak spots are the traction control system, by-wire throttle, electric windows and tyre pressure monitoring system.
Check the ABC system for rusty pipes and leaky seals, which cause the hydraulic pump to run dry. It can fail at 60k miles, too, if fluid isn’t changed. A new one is around £1500. In 2008, the system was recalled for possible acceleration sensor failure. Suspension struts are a common MOT test fail.
The Sensotronic Brake Control (SBC) was the subject of various recalls so check the car was seen. The system is designed for around 100,000 miles before car goes into limp mode.
Dents in aluminium body panels can be a devil to put right. Check the boot for damp, which can short the roof motor and the central locking vacuum pump. When roof is raised, listen for creaks that could indicate poor alignment. Look for rust on the rear wheel arches.
Also worth knowing...
If the vario-roof goes west, contact a roof specialist such as Cayman Auto Services. Faults they encounter include sticking bootlids, seized roofs, noisy roof operation, faulty pumps, poor roof/frame alignment, blocked drain holes, water ingress, sticking windows and more.
Mercedes SL55 AMG prices...
Early (2002/03) private-sale cars with around 100k miles and partial history.
Dealer-sale 2002/03 cars with around 70k miles, plus higher-mileage cars.
Some 2004/05 cars with 70,000 miles, plus low-mileage 2003-2005s with under 50k miles.
A host of 2003-2007 cars with less than 50k miles.
More bullishly priced 2003-2007 cars, most with very low mileages and full main dealer histories.
Rare SL55 with the F1 pack (which includes uprated suspension, larger wheels and revised brakes).