Overheating on the 2003 Chevrolet Impala
When overheating gets reported
Owners of the 2003 Chevrolet Impala report overheating at a median of 100,000 miles. A quarter of the reports come in before 65,000 miles and a quarter after 200,000 miles, from 16 reports that carried an odometer reading.
A part like this is normally expected to survive 102,000 miles. It is the 13th most-reported problem on this model year.
The mileage distribution
The reported range runs from 45,000 miles at the tenth percentile to 200,000 miles at the ninetieth, a spread of 152,850 miles across the middle 80% of reports.
When the reports scatter this far, the mileage is telling you about how these cars were driven more than about the part itself.
0% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 47,150 miles | 65,500 miles | 100,953 miles | 200,000 miles | 200,000 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 $400–$3,500 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 12 model years of this car. It shows up earliest on the 2006, at a median of 5,000 miles, and latest on the 2000 at 150,000 miles.
By volume the 2004 carries the most reports, with 22; the 2003 has 18. 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.
Heater quit working, then car started overheating. Turning off heater/defroster causes it to stop overheating so much, but temperature still rises when waiting at lights. Car is also needing oil replacement, after having an oil change 2 months and 1500 mi ago. Mileage is around 60,000. There is oil leaking out in various places around the engine. *jb
Heater quit working, then car started overheating. Turning off heater/defroster causes it to stop overheating so much, but temperature still rises when waiting at lights. Car is also needing oil replacement, after having an oil change 2 months and 1500 mi ago. Mileage is around 60,000. There is oil leaking out in various places around the engine. *jb
I own chevrolet impala which is less than 3 years old. The coolant is supposed to last 100,000 miles or more. But the system has problems and it leaks. The car gets overheated and presents a fire hazard. *nm
Also reported on the 2003 Chevrolet Impala
Other electrical problem
No-start or intermittent start failure
Other engine problem
Ignition switch, key fob or immobilizer failure
Other lighting problem
Headlight failure or clouding
How far this goes
Complaints are voluntary, so 18 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 overheating happen on the 2003 Chevrolet Impala?
Across 16 owner reports that included an odometer reading, half were filed by 100,000 miles. A quarter were filed before 65,000 miles and a quarter after 200,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is overheating on the 2003 Chevrolet Impala?
18 reports have been filed with NHTSA, about 0.2 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