Common Mercedes 300 Problems, Faults, and Repair Costs
Typical MOT issues to check on the Mercedes 300, with rough repair costs, and its MOT pass rate for each model year. Based on 3,966 MOT tests across 5 model years (DVSA data for tests carried out in 2024, retests included).
Segment: premium performance | Fuel: Petrol, Diesel
82%
Mercedes 300 pass rate
87%
Mercedes average
82%
All-model average
The Mercedes 300 has an average MOT pass rate of 82%, which is 5 points below the Mercedes average and equal to the average across all models in our data. The Mercedes 300 has maintained consistent MOT pass rates across model years, varying by only 0 percentage points.
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Common MOT Issues to Check on the Mercedes 300
Typical issues for a car of this age and type, estimated from its age, fuel type and engine size (not counted from its MOT records), with rough repair costs
Brakes
High likelihood£80 - £450
Typical repair cost
Common advisories:
Brake discs worn, brake pads thin, handbrake adjustment needed
Failure points:
Brake disc excessively worn, brake pipe corroded, brake efficiency below minimum
Suspension
High likelihood£150 - £600
Typical repair cost
Common advisories:
Suspension arm bush worn, shock absorber misting, spring corroded
Failure points:
Coil spring broken, ball joint excessive play, shock absorber leaking
Lights
High likelihood£15 - £200
Typical repair cost
Common advisories:
Headlamp aim slightly out, lens deteriorated
Failure points:
Headlamp not working, brake light not functioning, indicator failure
Tyres
High likelihood£50 - £300
Typical repair cost
Common advisories:
Tyre approaching legal limit, slight damage to sidewall
Failure points:
Tyre below minimum tread depth, tyre has a cut exposing ply
Exhaust & Emissions
High likelihood£80 - £800
Typical repair cost
Common advisories:
Exhaust mounting corroded, slight exhaust leak
Failure points:
Exhaust emissions exceed limits, catalytic converter efficiency low, DPF warning
Steering
High likelihood£100 - £500
Typical repair cost
Common advisories:
Track rod end has slight play, steering rack boot deteriorated
Failure points:
Steering rack leaking, track rod ball joint worn beyond limits
Body & Structure
High likelihood£200 - £1200
Typical repair cost
Common advisories:
Surface corrosion on subframe, slight body panel damage
Failure points:
Structural corrosion, body mounting corroded through, chassis weakness
Windscreen & Wipers
Lower likelihood£10 - £350
Typical repair cost
Common advisories:
Minor windscreen chip, wiper blade deteriorated
Failure points:
Windscreen crack in swept area, wiper does not clear windscreen
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Mercedes 300 Reliability by Year
MOT pass rate for each model year, from DVSA data for tests carried out in 2024 (retests included). Newer cars usually pass more often simply because they are younger. Highest and lowest are marked among years with 100+ tests that were at least three years old when tested. Fuel and engine size are a guide only.
Mercedes 300 Running Costs
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What are the most common Mercedes 300 problems?
Typical issues to check on a Mercedes 300 of this age and type are brakes, suspension, lights, tyres, exhaust & emissions, steering and body & structure. These are estimated from its age, fuel type and engine size, not counted from its MOT records. Across 3,966 MOT tests (DVSA MOT data for tests in 2024, retests included), 82% ended in a pass.
Is the Mercedes 300 reliable?
The Mercedes 300 has an average MOT pass rate of 82%, from 3,966 MOT tests. That is level with the average across all models in our data (82%), so about average. Pass rates fall as cars age, so compare it with cars of a similar age.
Which year Mercedes 300 is the most reliable?
Of the years with at least 100 tests that were old enough for a routine MOT, the 1990 Mercedes 300 has the highest MOT pass rate: 84% of its 947 tests ended in a pass. The 1991 has the lowest at 81%. Newer cars usually pass more often simply because they are younger, so the pass rate is only part of the picture.
How much does it cost to fix common Mercedes 300 faults?
As a rough guide, brake work on a Mercedes 300 typically costs £80-£450 and suspension repairs £150-£600, while exhaust and emissions fixes can cost £80-£800. Lighting and wiper fixes are usually under £200.
Check a Specific Mercedes 300
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Other Mercedes Models
Common problems pages for other Mercedes models