Misfire or rough idle on the 1999 Audi A4
Only 1 report for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.
When misfire or rough idle gets reported
There are 1 report of misfire or rough idle on the 1999 Audi A4, 1 with a mileage attached. That is too few to place the failure on the odometer with any confidence.
A part like this is normally expected to survive 92,000 miles. It is the 30th most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 98,000 miles | — | — |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $250–$1,600 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
The same failure on other years
The same failure is reported on 6 model years of this car. It shows up earliest on the 2002, at a median of 10,000 miles, and latest on the 1998 at 110,000 miles.
By volume the 2002 carries the most reports, with 48; the 1999 has 0. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
This is the 2nd coil pack failure I have had on my 1999 audi a4 1.8t. It was first replaced by southbay audi in ca in june of 2002 and then now october on 2004. After reading thousands of complaints made by audi and vw owners on www.audiworld.com it is apparent to me that this is definitely a serious manufacturer defect. My car suddenly lost power on the hwy while traveling on the hwy 405 in ca...if it had not been for the attentive driver behind me...the cars loss of power due to loss of cylinder one in my 4 cyldr car would have been catastrophic. I took my car to my trusted mechanic and found that the coil pack was bad due to a misfire in cyldr 1. I now have to spend out of pocket to repair this problem that in my opinion was an existing problem from the day the car came out of the production plant in germany. Kindly advise of my options to recoup my expenses. *jb
Also reported on the 1999 Audi A4
ABS module or sensor failure
Timing chain, belt or tensioner failure
Other brake problem
Control module (ECM/PCM/BCM) failure
Steering rack, gear or tie rod failure
Other speed control problem
How far this goes
This page is kept out of search results because 1 report is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.
Complaints are voluntary, so 1 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does misfire or rough idle happen on the 1999 Audi A4?
Across 1 owner reports that included an odometer reading, half were filed by 100,000 miles. A quarter were filed before — and a quarter after —. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is misfire or rough idle on the 1999 Audi A4?
1 reports have been filed with NHTSA, about 0.1 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed