2001 Toyota 4RUNNER Problems

What owners report

Owners of the 2001 Toyota 4Runner most often complain about frame and underbody corrosion, which shows up as rust perforation around the rear control-arm mounts, near the muffler, and on the rear axle/differential housing. Complaints also cover leaks from a corroded rear differential housing and, less often, driveline noises, front suspension and steering symptoms, and engine/drivetrain noise. Reports arrive across a wide mileage range, usually well past 90,000 miles.

1. 1
   Body and structure

   Frame rust-through around rear suspension mounts

   Mentioned in 33 of 60 sampled complaints

   Owners describe frame rails rusting through, especially near the rear control-arm brackets, the muffler, and the wheel wells, sometimes with visible holes or metal that flakes off by hand. Several say the vehicle failed a state inspection because of the frame, and that a rear trailing arm had separated from the rotted frame, producing swaying or a pop while driving. Complaints describe dealers and independent shops confirming the corrosion and telling owners the vehicle was not safe to drive or could not be repaired, with the manufacturer generally declining assistance. Mostly reported between roughly 90,000 and 230,000 miles, often found during routine maintenance, inspection, or shock replacement.

   What to check: Have a pre-purchase inspection look closely at the frame rails near the rear control-arm mounts, the muffler area, and above the rear axle, probing for soft or perforated metal. Ask whether the frame has ever been welded or patched.

   2 excerpts from owner complaints in NHTSA records

   “Entered highway from on ramp as picked up speed steering wheel began to shake violently and began to loose control of SUV. I immediately pulled over and had it taken to shop to find excessive rust on back frame n shock causing wheel to 'basically be free floating and unattached' the vehicle is still in shop at moment and I can get pictures and a statement upon request”

   NHTSA complaint #11281067, filed 2019-11, 98,005 miles

   “Suspension mount on frame in front of driver's rear wheel broke off due to unusual amount of rust. This impaired control of vehicle at speed, I almost went in ditch as rear of vehicle swayed back and forth severly (like rocking a boat) I had this repaired to continue driving. As of 8-30-15 the same part on other side is almost broken off research shows this to be very common,why is it not addressed?”

   NHTSA complaint #10760404, filed 2015-08, 275,200 miles
2. 2
   Transmission and drivetrain

   Rear axle and differential housing rust and gear oil leaks

   Mentioned in 11 of 60 sampled complaints

   Owners report the rear differential housing rusting through and leaking gear oil, sometimes leaving black spots on the rear window or fluid dripping under the vehicle. Some describe the fill plug area becoming too rusted to check the fluid level, and a few say the housing was replaced or patched at their expense. In several accounts the body was otherwise rust-free, which owners found surprising. Typically reported from about 80,000 to 200,000 miles, often noticed as a leak while parked.

   What to check: Look under the rear of the vehicle for wet or oily residue on the differential housing and for heavy scaling rust, and ask whether the housing has been replaced or repaired.

   2 excerpts from owner complaints in NHTSA records

   “When on a long highway trip on the weekend of june 7, 2008, my husband noticed black spots on the rear window of our 2001 Toyota 4RUNNER (121,000 miles). He cleaned it off to see if it returned as we resumed our journey. When we next stopped several hundred miles later, the black spots were on the entire rear of the vehicle. My husband checked beneath the rear of the vehicle and saw transmission fluid dripping out of the differential. …”

   NHTSA complaint #10231201, filed 2008-06, 122,000 miles

   “My 2001 4 runner with only 125,000miles has a rusted out rear differential. This was shocking to me because my truck is in otherwise excellent condition and has absolutely no rust on the body. I took it to Toyota who said they can replace it for $2200 plus tax. I took it to my husband's mechanic to repair/patch it if possible. He said he has seen many vehicles with more miles than mine in much worse condition that have no rusted out rear differentials. He found it very unusual. …”

   NHTSA complaint #10267566, filed 2009-05, 125,125 miles
3. 3
   Suspension

   Front suspension and steering looseness or pull

   Mentioned in 7 of 60 sampled complaints

   Owners describe steering wheel jerk or pull to one side, a sudden beeping warning with momentary loss of control, and vibration or shaking that made the vehicle hard to control. Explanations from shops included corroded frame and shock mounts and, in one case, a failed lower ball joint. Some repairs involved replacing shocks or ball joints, and in other cases the frame rot prevented repair. Reported from about 98,000 to 275,000 miles, often while turning or at highway speed.

   Recall 05V225000

   What to check: Ask whether the front lower ball joints have been replaced and check for play or looseness; inspect shock mounts and the frame around the front suspension for rust.

   2 excerpts from owner complaints in NHTSA records

   “On three separate occasions my 2001 Toyota forerunner has had an issue where the steering wheel pulls to the right and locks up for about a second. On each occasion I was on a right hand curve in the road and was accelerating through the turn after initially slowing down to begin the curve. On each occasion I was obeying the posted speed limit for the section of the road where the curve was located. …”

   NHTSA complaint #10354396, filed 2010-09, 98,000 miles

   “We were told today that our 2001` Toyota 4-runner has frame rot that is inconsistent with the age of the vehicle and the condition of all the other parts on it. Frame rot that constitutes a danger to our safety when driving it. The repair technicians advised us to determine if it was part of Toyota's frame rot recall with the tacomas and other vehicles because the frame rot rust was consistent with the pattern of damage they had seen on other recalled vehicles. …”

   NHTSA complaint #10865769, filed 2016-05, 135,000 miles
4. 4
   Transmission and drivetrain

   Driveline vibration and rear-end noises

   Mentioned in 4 of 60 sampled complaints

   Complaints describe vibration at highway speed, a thumping or banging from the rear, and in one case a jolting stop with a loud bang and dragging tires. Owners report that dealers sometimes could not initially find a cause, while others found vibration from the driveshaft or a rear-end problem. One owner had a transmission fluid leak traced back to a corroded rear axle housing. Reported from roughly 100,000 to 200,000 miles, often at highway speeds.

   2 related service bulletins

   What to check: Drive the vehicle at highway speed and listen for a steady drone or vibration, and have the driveshaft and rear axle assembly inspected along with fluid levels.

   2 excerpts from owner complaints in NHTSA records

   “On october 11th 2014, I was driving my 2001 4RUNNER, on my way to work. Had just turned off a road with a speed limit of 55. As I hit 35mph, my car comes to a jolting stop with a loud bang and drag on the tires. The car still ran, but the car wouldn't move. I had to finish walking to my job, as I was cellphone-less at the time. I had to pay to have my car towed home, missing an entire day's work, which was a loss of 120$. The guy who towed me told me it was definitely something to do with my rear end. …”

   NHTSA complaint #10651885, filed 2014-11, 198,000 miles

   “When driving at 70 MPH, the vehicle vibrates on the highway. I have taken the vehicle constantly to the dealership for over two years complaining about this problem and they always told me that nothing was wrong. Today (5/10/14), the mechanic at the dealership put the truck on a rack and ran the car at 45 MPH and there was visible vibration coming from the drive shaft and a loud noise that I could never hear from within the vehicle. All this time, I have been driving a vehicle that I was unaware could have snapped apart. …”

   NHTSA complaint #10587585, filed 2014-05, 107,000 miles
5. 5
   Engine cooling

   Engine and drivetrain noise or stalling

   Mentioned in 4 of 60 sampled complaints

   A small group of complaints describes loud noises followed by loss of power or vibration, including one account of a connecting rod separating from the crankshaft and puncturing the oil pan. Another owner reported an engine that would not accelerate and a dealer quoting a rebuilt engine. One complaint describes an engine compartment fire, and another a check engine light with traction control disabled that a dealer attributed to computer programming. Reported from about 47,000 to 120,000 miles, with no consistent pattern.

   1 related service bulletin

   What to check: Listen for knocking or unusual noise on start-up and during a test drive, check for an illuminated check engine light, and ask about oil changes and any engine repairs.

   2 excerpts from owner complaints in NHTSA records

   “I was driving my truck on a city street in brooklyn, new york ( flatbush ave) when I suddenly smelled smoke followed by fire coming from the hood. I did not hit any bump and was not involved in any accident. By the time the fire department came, the entire front compartment of the truck was on fire.”

   NHTSA complaint #11066126, filed 2018-01, 112,000 miles

   “The contact owns a 2001 Toyota 4RUNNER. While driving approximately 35 MPH, the check engine indicator illuminated and the traction control became disabled. The dealer stated that the programming of the computer needed to be reconfigured. The manufacturer was not notified of the failure. The vehicle was not repaired. The approximate failure mileage was 120,000.”

   NHTSA complaint #10644643, filed 2014-10, 120,000 miles

Buying note. Frame and underbody corrosion is the main thing to check on this model year, so an inspection focused on the frame, rear axle housing, and suspension mounts is worth it before buying. Records of prior welding, differential repairs, and ball joint replacement help show how the vehicle has been maintained.

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. Counts refer to that 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.