2004 Toyota 4RUNNER Problems

What owners report

Owners of this model year most often write about rust and corrosion on the frame and underbody, which in many reports was found at annual state inspections or during routine service and in some cases left the vehicle unable to pass inspection. Complaints span a wide mileage range, from under 100,000 to well past 200,000 miles, and a second, smaller group describes brake and suspension parts seizing or separating where they attach to the frame.

1. 1
   Body and structure

   Frame and subframe rust-through

   • 362 complaints (53%)
   • median 140,000 mi at 15.0 yrs old (227 state mileage)
   • 2 mention a crash, fire or injury
   • owner-quoted repair $4,150 (median of 6 quotes)
   • filed 2009–2026

   Complaints describe rust holes in the frame rails, subframe, radiator support and body mounts, often discovered during state safety inspections, routine oil changes or when the vehicle is on a lift. Several owners say the body panels are clean while the underside is heavily corroded, and some report the vehicle was declared unfit to drive by a mechanic or inspector. According to complaints, dealers typically declined repairs and some owners were told their VIN was no longer covered by an extended warranty for the condition. Reported from roughly 74,000 to over 200,000 miles, with many complaints in the 100,000-165,000 mile range; several owners mention salted winter roads, while others say the vehicle was garaged or washed regularly.

   What to check: Have the frame and subframe inspected on a lift before buying, especially around the radiator support, body mounts and rear trailing-arm brackets, and look for flaking metal or holes. Ask whether the vehicle has passed a state safety inspection recently and whether any frame repairs or welds have been done.

   2 excerpts from owner complaints in NHTSA records

   “While driving the vehicle and after turning onto a state highway it suddenly swerved badly and the rear end began swaying back and forth making it uncontrollable. I stopped the car immediately. It was discovered that the frame had rusted so badly it became separated from the rear axle. I had to tow it home on a flatbed trailer.”

   NHTSA complaint #11367090, filed 2020-10, 78,000 miles

   “I've had this 2004 Toyota 4RUNNER since 2004 I bought it new and have taken good care of it. The body still looks great, no rust on body just has 94000 miles on it. But the under side is awful the frame has holes rusted through at high pressure points like suspension points, cross members for transmission and engine rusted through, its to point that its dangerous to drive. …”

   NHTSA complaint #11099336, filed 2018-06, 85,000 miles
2. 2
   Suspension

   Suspension and axle mounts separating from rusted frame

   • 101 complaints (15%)
   • median 137,000 mi at 15.1 yrs old (70 state mileage)
   • 5 mention a crash, fire or injury
   • filed 2005–2025

   Complaints describe trailing arms, stabilizer bars, body mounts or the rear axle detaching from a rusted frame, sometimes with a loud popping or banging sound while driving at low speed. Owners report the vehicle became unstable or began to sway, and mechanics who inspected it attributed the failure to corrosion of the mounting points. In several cases the vehicle had to be towed and was declared unfit to drive. Mostly reported between about 75,000 and 220,000 miles, often on vehicles with visible frame corrosion.

   What to check: Inspect the rear trailing-arm brackets and body mounts for rust and cracks, and ask whether any suspension work has been delayed or welded because of frame condition.

   2 excerpts from owner complaints in NHTSA records

   “This well maintained vehicle had been functioning flawlessly up to this point. Our son was on his way home and vehicle felt unstable and started to veer in both directions. He maintained control of the vehicle and was able to get home. I personally drove the vehicle upon his description and sure enough it seemed very unstable. After close examination, it was determined that the frame had separated at a location which left a drivers side rear stabilizer bar detached from the frame. …”

   NHTSA complaint #11331522, filed 2020-06, 220,000 miles

   “We have a 2004 4RUNNER with extreme body rust a corrosion which has caused the failure of numerous components, brakes, gas tank, transmission lines, wheels and other suspension and exhaust items. We originally noticed this failure and began taking steps to correct areas of concern, but the excessive rust has prevented many repairs on suspension, brakes and other components. We recently had an incident that almost caused a roll-over when the brakes seized and the transmission lines failed. I can describe this in more detail at request. …”

   NHTSA complaint #11322729, filed 2020-04, 75,000 miles
3. 3
   Brakes

   Brake lines and calipers corroded or seizing

   • 91 complaints (13%)
   • median 85,500 mi at 10.7 yrs old (68 state mileage)
   • 6 mention a crash, fire or injury
   • owner-quoted repair $3,100 (median of 13 quotes)
   • filed 2003–2025

   Owners describe brake lines and fittings corroded through, brake fluid leaks and calipers that seized, in one case at the front and later at the rear. Some complaints describe warning lights and a pedal that did not stop the vehicle, followed by towing and a repair estimate in the thousands of dollars. Dealers and shops replaced lines, calipers and fittings according to the complaints. Reported from about 50,000 to over 300,000 miles, with several between roughly 100,000 and 165,000 miles.

   3 related service bulletins

   What to check: Ask for brake line and caliper service records and have the lines inspected along the frame for corrosion. A service bulletin notes that some Toyota pads can produce a groan or squeak noise, which is a separate noise concern.

   2 excerpts from owner complaints in NHTSA records

   “Transmission would not shift in motion leaving from a stop sign. I later found out my transmission lines had corroded away leaking a large amount of transmission fluid. After replacing brakes and adding brake fluid I noticed the brake fluid had leaked from bottom. I had to replace all brake lines and fittings due to corrosion.”

   NHTSA complaint #11322167, filed 2020-04, 190,000 miles

   “I have had two incidents of brake calipers failure. Under 50k I had a front driver side caliper fail. Then again at 99k the rear passenger side caliper failure. Toyota has a major issue with their brake caliper design on 4-runners. Toyota should extend their warranty, I always bought Toyota's, but never again after this last incident. Toyota does not build cars like they use to.”

   NHTSA complaint #10614845, filed 2014-07, 99,000 miles

Buying note. Frame condition matters more than mileage on this model year: have the underside inspected on a lift before purchase and ask for inspection and repair history. Also confirm recall work for the accelerator pedal and side curtain airbags, and check brake lines for corrosion.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.