Unclassified problem on the 1998 Ford Expedition
12 crashes 1 fire 8 injuries 21 of the 24 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.
Only 9 reports 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 unclassified problem gets reported
Owners of the 1998 Ford Expedition report unclassified problem at a median of 110,000 miles. A quarter of the reports come in before 75,000 miles and a quarter after 130,000 miles, from 9 reports that carried an odometer reading.
It is the 68th most-reported problem on this model year.
The mileage distribution
The reported range runs from 50,000 miles at the tenth percentile to 145,000 miles at the ninetieth, a spread of 94,400 miles across the middle 80% of reports.
A spread this wide points at use rather than design. Towing, climate, service history and city mileage all move a failure like this, so the median is a weak guide to any individual car.
11% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 49,200 miles | 72,500 miles | 112,000 miles | 128,000 miles | 143,600 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, 12 a crash, 1 a fire and 8 an injury are 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.
The same failure on other years
The same failure is reported on 24 model years of this car. It shows up earliest on the 2021, at a median of 15,000 miles, and latest on the 2001 at 120,000 miles.
By volume the 2003 carries the most reports, with 55; the 1998 has 24. 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 has occurred 8 or 9 times in the last 4 weeks' (the most recent being 01/14/2003) my 98 e/b 4x4 recently began over accelerating at intermittent times. (I live in mn, and have noticed this problem is worse when the temp is below zero.) I have had 2 minor accidents already because out of the blue my vehicle takes off as though it is going 70 miles an hour. The brakes do not seem to work when this is occurring. In order to stop this from occurring, I need to quickly shift into neutral, which causes the engine to rev up to 4500 RPM. I have tried restarting the engine multiple times, and kicking down the gas pedal, and each time the RPM remains high. When I am traveling at highway speeds, and this begins to occur, the engine revs to 3000 RPM, and drives itself at 65-70 MPH (acts almost as if the cruise is set). I have been stranded twice now, and have found that once the vehicle sits for 10 minutes or so, it seems to be ok.
Safety belt on 98 ford expdition will not function. Belt will latch, then when pulled, will release. The cover on the belt is loose and it will not function properly. Have contcted ford 6 times with no reply.
Vehicle was involved in a frontal collision of 35 MPH and neither frontal air bag deploy. No injuries was reported at this time and the dealer was notified. *nm the consumer stated that she is experiencing some on going ligament and nerve damage in her back and neck. *tc
Also reported on the 1998 Ford Expedition
Other suspension problem
Misfire or rough idle
Other electrical problem
Other engine problem
Other wheel or tire problem
Other body or interior problem
How far this goes
This page is kept out of search results because 24 reports 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 24 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 unclassified problem happen on the 1998 Ford Expedition?
Across 9 owner reports that included an odometer reading, half were filed by 110,000 miles. A quarter were filed before 75,000 miles and a quarter after 130,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is unclassified problem on the 1998 Ford Expedition?
24 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