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Mercedes-Benz 450SEL 6.9 (1975 - 1981)

Last updated 11 February 2014

 
5

Buying Guide

Good

  • Immense performance
  • Acres of interior room
  • Massive road presence
  • Unimpeachable build quality

Bad

  • Huge thirst and running costs
  • Parts prices for 6.9-specific items can be eye watering

Watch

  • These cars are so expensive to fix - if it's a 6.9-related problem - that they end up laid-up and out of action. So, check for signs that you're not looking at a car that's been out of use and not properly recommissioned.
  • Rust isn't a particular problem, thanks to high-quality steel, but it's not unknown for lightly-used non-garaged cars to suffer from corrosion. Always check the leading edges of the sills, inner wings and door bottoms.
  • The M100 engine is near-bulletproof, thanks to being so unstressed. Make sure that oil has been changed on a time - and not mileage basis - for lightly used cars.
  • Check the big-end and main bearing shells on any low mileage cars.
  • but water pumps can cost £3000-plus to fix.
  • Fuel injection is reliable.
  • Transmission is extremely tough.
  • Hydraulics can cause problems - on the 6.9, and its long pipe runs, check closely for leaks. They can occur anywhere.
  • Hydraulic pump failure is rare, but costly, so make sure it's quiet and operational.
  • Also check the condition of the accumulator - it stores pressure.
  • Make sure the suspension system charges as it should - when fired-up, the red light on the dash should go out after no more tha 20 seconds.
  • Interiors were often velour and PVC, with leather an optional extra - retrimming is strightforward and not cheap.
  • Also make sure the interior wood is all as it should be - there's a lot of it, and it is expensive to refurbish.
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