Similar to Mercedes-Benz S-Class models that went before and after, the W220 was another showcase of the latest automotive designs and patents in electronics and electro-mechanical devices. Like the new W222 generation, this range was the benchmark for large luxury sedans and the facelifted version that was introduced in late 2002 ushered in minor aesthetic upgrades, but a raft of interior updates.
SUSPENSION, STEERING AND BRAKES
All W220 models had air suspension driven by a small compressor with an air-valve distributor to the air struts. If the car sags after standing, there could be leaks. Try using soapy water on all the joints to check for air leaks. Blown fuses can also indicate an overworked pump.
TRANSMISSION AND STEERING
The automatic transmissions had five gears since the 7G-tronic seven-speed arrived only with the successor, the W221, in late 2005. There were very few problems noted with these units and the five-speed version is generally regarded more user-friendly than later transmissions.
The S350 had a 3,7-litre V6 (180 kW), S320 CDI a 3,2-litre V6 turbodiesel (150 kW), S500 a naturally-aspirated 5,0-litre V8 (225 kW), S55 AMG a 5,4-litre supercharged V8 (368 kW) and S600L a turbocharged 5,5-litre V12 (368 kW and 800 N.m). On the diesel model, the biggest problem appears to be leaking injectors. Remove the engine cover and check for signs of diesel oil-seepage. Replacing the seals is often all that’s necessary, but special tools are recommended to avoid breakage, leading to further expense. If not fixed early, the injectors may become stuck in the head and need to be replaced at great cost.
Some paint bubbling and rust spots may occur after a decade or so – keep the paintwork well waxed and park the large sedan under cover. Make sure that you test all the bells and whistles. The ones that don’t work will be costly to repair/replace.
Watch out for the accumulation of leaves under the bonnet near the firewall, which is the source of the interior ventilation. Blocked air passages can lead to rainwater entering the cabin, which may cause devastating damage to the electronics system.
Also look at:
BMW 7 Series, Audi A8, Jaguar XJ, Porsche Panamera, Lexus LS