Overheating on the 2004 Chevrolet Impala
2 injuries 2 of the 22 reports for this failure mention a crash, a fire, an injury or a death. Those are the owner's words on the complaint form, not a verified finding, and one report can mention more than one.
When overheating gets reported
Owners of the 2004 Chevrolet Impala report overheating at a median of 45,000 miles. A quarter of the reports come in before 35,000 miles and a quarter after 55,000 miles, from 20 reports that carried an odometer reading.
A part like this is normally expected to survive 102,000 miles. It is the 15th most-reported problem on this model year.
The mileage distribution
The reported range runs from 35,000 miles at the tenth percentile to 75,000 miles at the ninetieth, a spread of 40,260 miles across the middle 80% of reports.
A window that narrow is the signature of a part that fails on its own schedule rather than on how the car is driven — which is usually a design or supplier problem rather than wear and tear.
30% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 32,552 miles | 35,000 miles | 46,744 miles | 56,250 miles | 72,812 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
Of these reports, 2 an injury is mentioned. Owners write their own complaints and the agency does not verify them, so read this as what the reports say happened rather than as a confirmed count.
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 is the worst of them, which makes this a problem of this specific year rather than of the model as a whole.
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.
On oct 6th 2005, while driving the department issued 2004 chevrolet impala, police patrol squad car, I noticed a unfamiluar very strong foul odor when I would turn on the heater. Unknown to me at the time, but after I sufferred initially an inhalation injury which nearly killed me by sufficating me causing my blood pressure to escalate thereby causing me to suffer duel anyursm' of the upper thoracic vein and the abdominal vein. I was flown via flight-for-life helicopter to a trauma center, hospitalized in intensive care, left incapacited me for four months and without an income. I am now left with internal scar tissue on my aorta vein. My police supervisor visited me in intensive care in the hospital and informed me that the mechanic from the dealership which services our fleet of leased vehicle, inspection results indicated that the electrical system was overcharging the battery and as a result the battery began to overheat giving off battery acid fumes which explained the foul odor. *jb
On oct 6th 2005, while driving the department issued 2004 chevrolet impala, police patrol squad car, I noticed a unfamiluar very strong foul odor when I would turn on the heater. Unknown to me at the time, but after I sufferred initially an inhalation injury which nearly killed me by sufficating me causing my blood pressure to escalate thereby causing me to suffer duel anyursm' of the upper thoracic vein and the abdominal vein. I was flown via flight-for-life helicopter to a trauma center, hospitalized in intensive care, left incapacited me for four months and without an income. I am now left with internal scar tissue on my aorta vein. My police supervisor visited me in intensive care in the hospital and informed me that the mechanic from the dealership which services our fleet of leased vehicle, inspection results indicated that the electrical system was overcharging the battery and as a result the battery began to overheat giving off battery acid fumes which explained the foul odor. *jb
Like many impala owners before me, the instrument panel on my 2004 impala has failed after 3 1/2 years and 60,000 miles. It started out with the speedometer and then the temperature gauge went. This is a serious problem as you have absolutely no way to tell how fast you are going or if your car is going to overheat. Vehicle was repaired at a gm dealer and gmc was contacted and refused to cover the cost. *cn
Also reported on the 2004 Chevrolet Impala
Instrument cluster or gauge failure
Other electrical problem
No-start or intermittent start failure
Ignition switch, key fob or immobilizer failure
Other engine problem
Other lighting problem
How far this goes
Complaints are voluntary, so 22 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 2004 Chevrolet Impala?
Across 20 owner reports that included an odometer reading, half were filed by 45,000 miles. A quarter were filed before 35,000 miles and a quarter after 55,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is overheating on the 2004 Chevrolet Impala?
22 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