Audi A4 TDI SE (2004)
2004 Audi A4 TDI SE
CarHunch analysed 560 real MOT records for the 2004 Audi A4 TDI SE. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.
This 2004 A4 TDI is a significantly unreliable proposition: only 44% pass their MOT first time, compared to the UK average of 80%, and these vehicles are routinely failing rather than just picking up advisories. The good news is that dangerous defects are absent from this cohort, so while these cars need work, they're not mechanically unsafe in the way some older models are.
At nearly 190,000 miles median, these A4s have done serious mileage, and the 0.84 average failures per vehicle suggests the TDI engine and running gear are wearing hard. If you're considering one, budget for immediate repairs—nearly six in ten will fail their next MOT—and factor in regular maintenance costs; this is a car to buy only if you're mechanically confident or have a trusted diesel specialist on speed dial.
What to check before buying a 2004 Audi A4 TDI SE
Practical pre-purchase checks for this age and model.
- 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
- 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
- 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
- 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.
Before you buy a Audi A4 TDI SE
MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.
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Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Diesel (99%) | 557 | 43.9% | 0.83 |
| Gas Bi-Fuel (1%) | 3 | 75.6% | 1.67 |
Mileage Distribution
Most 2004 Audi A4 TDI SE vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 2004 Audi A4 TDI SE vehicles fall between 160,877 and 217,427 miles.
2004 Audi A4 TDI SE — Still on the Road
Numbers are declining — 50 vehicles still getting MOTs in 2025 (16% of peak).
Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2017–2025.
MOT History Averages
Found a specific Audi A4 TDI SE?
Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.