Advice for buyers
What should I look for in a used Mercedes S-Class saloon?
An outstanding maintenance record and evidence that the car has been well cared for are vital if you’re going to minimise the chances of potentially expensive problems. Check every single gadget works and that the service regime has been adhered to. This includes changing the oil in the seven-speed automatic gearbox every 40,000 miles and making sure it shifts smoothly.
On a test drive, also pay attention to the suspension, and particularly that it keeps the car completely flat when cornering. If not, a new pump could be required.
The Comand sat-nav system only allows you to enter a four-digit postcode, but this can be upgraded to seven-digit functionality by Mercedes. If this hasn’t been done, ask for the work to be completed before agreeing to buy the car.
By the time this S-Class, otherwise known as the W221, was launched, Mercedes was getting on top of its build quality issues, but some owners have still reported finding corrosion or blistered paint, so check over the car thoroughly, and if in doubt, pay for a professional inspection.
There have been a few recalls affecting the S-Class, most notably for a potentially faulty fuel filter on diesel models built between January 2009 and December 2011. If not addressed, this can lead to a fuel leak.
Some of the electrical connectors on cars built until the end of 2007 were also identified by Mercedes as not fit for purpose and replaced free of charge.
What are the most common problems with a used Mercedes S-Class saloon?
While there are isolated reports of very expensive engine failures, the S-Class as a whole appears to be mechanically robust, a point backed up by the number of very-high-mileage examples for sale on the used market. With the diesels, it's still worth listening out for excessive rattling at idle, which could indicate a stretched timing chain. If left unchecked, this can result in a catastrophic engine failure.
Electrical problems are more common and repairs can easily run into four figures. Among the more common issues are failed amplifiers, broken inflating seat bolsters and keyless entry that refuses to work. Owners also recommend using a trickle charger to keep the battery topped up if you’re due to leave the car standing for a long period of time, as a flat battery can play havoc with electrical systems.
Check the carpets are dry, too, as the rubber gromit in the drain airbox can fail and create a blockage. If not addressed quickly, this can not only flood the footwell but also wreck components such as the heater.
Is a used Mercedes S-Class saloon reliable?
Unfortunately, we didn’t have enough data on this version of the S-Class for it to feature in our latest reliability survey. Compared with its predecessor, however, the W221 is a much more robust machine and there are plenty of examples around running well into six-figure mileages with ease.