2002 Audi A4: what breaks, and at what mileage

What breaks on the 2002 Audi A4

Owners have reported 39 named failure modes on the 2002 Audi A4, and the three most-reported carry 45% of everything filed.

Misfire or rough idle leads with 48 reports, about 6.1 per 1,000 vehicles and with the middle half of reports between 4k to 15,000 miles.

Other electrical problem follows with 32 reports, usually reported between 8k to 20,000 miles. 3 of those reports mention a fire.

Headlight failure or clouding follows with 19 reports, usually reported between 885 to 110,000 miles. 2 of those reports mention a fire.

By system, the reports fall mostly into engine (75), electrical (36) and lighting (21).

Severity, and what it costs

Across the named modes, 13 mention a crash, 13 a fire and 6 an injury. Those are the words owners used in their own complaints, and NHTSA does not verify them, but they are the closest thing in this data to a measure of what a failure actually did.

The average severity weight across every report on this year is 3.89, where a stalled engine or a failed airbag weighs many times more than a rattling trim panel, and a figure this high means the reports are dominated by failures with safety consequences rather than annoyances. The weighting is set out in full on the methodology page.

What the top failures cost to put right, as editorial estimates for an independent US shop rather than figures from NHTSA: misfire or rough idle at $250–$1,600, other electrical problem at $250–$2,000, headlight failure or clouding at $150–$1,800 and other engine problem at $300–$4,000. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.

43% of the reports on this year sit in the engine, transmission, drivetrain or cooling systems — the four where a repair bill is usually four figures.

How often, against how many were built

Scaled by an estimate of how many of these cars exist, the 2002 Audi A4 draws about 28 per 1,000 vehicles, which puts it in the 94th percentile of complaint rates among 2002 vehicles we can rate.

That denominator is the weakest number on the page and it is fair to say so plainly. Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound.

The working figure is 7,851 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2002 vehicles, which is what the risk score uses, is far more robust than the rate itself.

Recalls on the 2002 model year

NHTSA has issued 2 recall campaigns covering the 2002 Audi A4, affecting an estimated 7,851 vehicles. A recall is a different kind of evidence from a complaint: it is the regulator and the manufacturer agreeing that something has to be fixed, and the fix is free for as long as the car exists.

The campaigns cover air bags:frontal:driver side:inflator module and engine and engine cooling:engine. Whether the work was actually done on the car in front of you is a question only the VIN can answer, and the manufacturer or NHTSA will answer it free.

Recalls also distort complaint counts. Publicity about a campaign reminds owners that complaining is possible, so reports for a recalled component often spike after the recall rather than before it.

How 2002 compares with the other years

High risk for a 2002 — 52nd riskiest of the 329 2002 vehicles we can rate. The comparison is always within the same model year, so an older car is never penalised for having had longer to break.

Across the 27 model years of this car that carry enough reports to score, 2016 comes out best at 56 and 2021 worst at 80, with 2002 itself at 74.

If the model year is negotiable, 2016, 2014, 1996, 2011, 2005, 2013, 2012, 2000, 2006, 2019, 2015, 2018, 1997, 1999, 2023, 2004, 2017, 2001, 1998, 2020 and 2007 score lower than 2002 by a margin worth acting on. Same body, same engines, different luck — usually a supplier change or a mid-cycle fix, which the complaint data can show but never explain.

Within the 1996–2004 generation specifically, 1996 is the strongest year at 62 and 2002 the weakest at 74.

What to look at before buying one

The mileages below are where the first quarter of reports for each mode had already been filed, which makes them the point at which a fault is worth looking for rather than the point at which it happens: air conditioning failure from about 300, headlight failure or clouding from about 885, misfire or rough idle from about 4k and other electrical problem from about 8k.

On a 2002 Audi A4 with more miles than that on it, the useful question to put to a seller or a mechanic is whether air conditioning failure has been dealt with, and if so with what parts and at whose expense. A car that has already had the repair is in a different position from one that has not.

None of this is a diagnosis. It is a list of what other owners of the same model year reported, ordered by when they reported it, which is a good place to point an inspection and a poor place to stop.

What this page cannot tell you

218 owner reports; fleet size estimated from this year's own recall paperwork. Every count on this page is therefore a floor: it is the number of owners who went to the trouble of filing with a federal agency, which is a small and self-selected fraction of the owners who had the fault.

Of those 218 reports, 142 carried an odometer reading, so the mileages here describe 65% of the sample rather than all of it. Owners also round: readings pile up on multiples of ten thousand, which is why this site publishes "about 90,000 miles" and not "91,438".

Named failure modes come from matching phrases in the complaint text, so a badly worded complaint can land in the wrong bucket. The effect washes out across hundreds of reports and does not wash out across five.

And nothing here predicts what one car will do. These are other people's complaints, filed years apart, on cars maintained by strangers. Read the page as a map of where this model year has previously gone wrong, then have the specific car in front of you inspected.