The M110 280 is THIRSTY , about 18 mpg at best with a light foot , some people run them on unleaded , others reckon they need the valves done or seek out the few remaining 4* pumps which still lurk here and there .
These cars were aimed at the American market - so don't think there is anything wrong when you find it has a very soft ride and generally 'floaty' handling : they were all like this even from new . The W124 series got back to the much sharper handling as found on the preceeding W114/115 series .
As said above - look for rust : front inner wings are a favourite place (make sure the drain channels next to the bonnet hinges are clear , otherwise trapped water can lead to rust) ; siezed bonnet hinges are another common fault with front wing removal needed to replace ; rear arches ; boot floor ; interior floorpans - lift carpets to check for water ingress .
The electric windows can tend to have slowed down in their old age - a combination of corroded electrical contacts (replace fuses with new ones even if not blown) and build up of dirt in mechanisms/lubrication drying out . The rear windows in the pillarless coupes can be particularly troublesome . Electric sunrooves can also give similar trouble , along with the well known rotting of the drain tube channels coming out of the tray which leads to water ingress .
The usual things like rotting of fuel and brake lines underneath need to be checked for , but these are very durable cars .
Having said all the above , some of these cars are 33 years old now , it is highly doubtful much of the newer stuff will have held up as well by the time they reach the same age .
If you do buy it , Mark Cosovich ( the UK's leading W123 guru - tel 01792 846888) will be your new , best friend .
Good luck .
