2004 Toyota 4RUNNER: what breaks, and at what mileage

What owners report breaking

Owners have reported 52 named failure modes on the 2004 Toyota 4RUNNER, and the three most-reported carry 44% of everything filed.

Other body or interior problem leads with 185 reports, about 2.2 per 1,000 vehicles and with the middle half of reports between 87k to 165,000 miles.

Rust or structural corrosion follows with 134 reports, usually reported between 119k to 182,500 miles.

Radiator or coolant leak follows with 53 reports, usually reported between 94k to 152,500 miles.

By system, the reports fall mostly into body (326), brakes (90) and suspension (85).

Severity, and what it costs

Across the named modes, 26 mention a crash, 6 a fire and 11 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 3.75, 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: other body or interior problem at $200–$2,000, rust or structural corrosion at $500–$6,000, radiator or coolant leak at $350–$1,900 and other suspension problem at $350–$2,000. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.

13% 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 2004 Toyota 4RUNNER draws about 9.9 per 1,000 vehicles, which puts it in the 86th percentile of complaint rates among 2004 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 85,202 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2004 vehicles, which is what the risk score uses, is far more robust than the rate itself.

Recalls on the 2004 model year

NHTSA has issued 2 recall campaigns covering the 2004 Toyota 4RUNNER, affecting an estimated 103,002 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:side/window and vehicle speed control:accelerator pedal. 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.

One caution about reading these together: a recall usually raises the complaint count for the same part, because owners who read about it go and file. The mileages stay informative; the counts get noisy.

Where 2004 sits in the model line

Elevated risk for a 2004 — 287th riskiest of the 329 2004 vehicles we can rate. Because the ranking is against the same model year only, age cancels out of it.

Across the 29 model years of this car that carry enough reports to score, 1996 comes out best at 52 and 2021 worst at 84, with 2004 itself at 60.

If the model year is negotiable, 1996 and 1998 score lower than 2004 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 1999–2006 generation specifically, 2001 is the strongest year at 58 and 2006 the weakest at 67.

What the numbers say to check

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: CV axle or driveshaft failure from about 24k, other powertrain problem from about 33k, other speed control problem from about 49k and brake line, hose or caliper failure from about 54k.

On a 2004 Toyota 4RUNNER with more miles than that on it, the useful question to put to a seller or a mechanic is whether CV axle or driveshaft 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.

Treat it as where to point the inspection, not as a prediction. A well-maintained example can sail past every mileage on this page, and a neglected one can fail well before the first of them.

The limits of complaint data

847 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 847 reports, 568 carried an odometer reading, so the mileages here describe 67% 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".

The failure modes are assigned by software reading the owner's own words, which is accurate in bulk and wrong in individual cases. A mode with a handful of reports may contain a misfiled one.

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.