Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl* the contact owns a 1999 Hyundai Sonata. The contact received repairs under NHTSA campaign id number: 09V124000 (suspension). The vehicle was taken to a local mechanic because the motor was excessively loud after the recall repair. In addition, the contact stated the vehicle would sway back and forth, the motor would jump abnormally and the steering would intermittently become hard. The contact was advised by the mechanic that the motor mounts were loose and to take the vehicle back to the dealer for repairs. The dealer advised that the motor mount was fractured but did not make repairs. On a separate occasion while driving 40 MPH, the rear of the vehicle began to sway abnormally. A vehicle crashed into the rear of her vehicle but did not stop. There were two passengers that sustained injuries to the knee, neck and back. A police report was available. The vehicle was not repaired. …
Consumer loss control and hit a solid barrier and none of the airbags deployed. Driver sustained a head injury. Prior to the accident the vehicle was taken to the dealer because the air bag light illuminated. The dealer removed and replaced the passenger seat air bag module. The dealer also performed recall 02V105000 related to the side impact air bag wiring harness routing. The rear defogger button flashed intermittently and the A/C and defogger were inoperative. The dealer replaced the control head. The outside rearview mirrors would not move right or left. Dealer found break in wiring in right kick panel. The check engine light illuminated. The dealer replaced the canister purge valve. * ph
Purchased car August 16th 2001 shortly after purchase about 3 months later the check engine light came on so I took it back to the place of which I purchased it wyatt johnson Hyundai dealership in clarksville tn . At that time the o2 sensor had went bad so that was replaced and we were also advised that it was way past due on transmission fluid which was their fault so they replaced that as well. A few months went by and the same thing happened again. These were once replaced again on the opposite side of the car. Also about 4 to 5 months later the check engine light came back on and the car was sputtering and then would not start because the spark plugs wires were fried as if they had caught on fire so they too replaced that with all new ones. …
"check engine" light comes on and off, no issue for few months, recently while stopping at red light with foot on brake, the RPM started increasing and vehicle tried to move forward, it took me by surprise and I was about to crash into the vehicle in front of me. This happened to me few times already, and everytime it is scary. I had to push hard on the brake to prevent the car from moving. I tired to change the gear from d to n, and that helped preventing the car from moving but the RPM jumped even higher and the engine made laud noise. I took the car to a mechanic, they connect it to the computer and said the coolant temp sensor and crank position sensor need to be replaced, that is $140 parts plus 4 hours of labor. Talked to Hyundai dealer, they said never heard of this problem, and there is no recall on it, so they have to do their own troubleshoot and I'm responsible for the bill. …
The engine will intermittently race increasing rpms without notice, very dangerous. It happened while sitting at a red light. If my foot was not pushed down on the brake I would have hit the car in front, it will also occur while in park with the engine rpms going up to 3200 and down to 1500 like it was a hunt lasting several minutes. It will stop ,but I can't figure out how or why. It seems to be worse when driving at sustained higher speeds on interstate, then getting off the exit. I do notice that when I accelerate away from a light while the prms are high the engine almost cuts off then picks up in a jerking motion. If I turn off the engine while the rpms are high racing I am not able to restart for a while. I smell gas, flooding I assume. The repair shop has not been able to correct it since it does not happen while in their hands.
I have an 1999 Hyundai Sonata my alignment was off from a pot hole. So I took it to get it repair. They told me that the engine cradle was rusted so bad that the arm came out of it. They said it is unsafe to drive. It only has 85,225 miles on the car to replace the cradle it is 1,800.00. I contacted Hyundai they said my warranty is up and there not going to fix it. I found that this a common problem with this year of Sonata. Its has caused one wreck that I now of. There is a flaw in the design of the cradle. There is only one hole in the front to let water in and out so if the water goes in the air blows it to the back and there's where it stays and that's the rust starts.
When the check engine light illuminated, vehicle ran sluggish, and then stalled. The dealer replaced the oxygen sensors four times within the last three years. The problem was still occurring and happened more frequently. Based on consumers assumption, the vehicle was having the same problems as described in NHTSA recall 00V259001 concerning stalling. This vehicle was not included in the recall due to VIN.
Engine cradle has rusted out on 1999 Sonata, also causing damaged control arm on right front tire. Repair costs are over $2000. Car has been well maintained throughout its life and has not been involved in any major accidents or collisions. What looked like simple misalignment of right front tire turned out to be a much bigger safety hazard.
Air box that is connected to the air hose fell off the engine, and laid in the engine compartment. This resulted in vehicle stalling . The first time this occurred check engine light came on after the vehicle stalled, the second time the check light didn't come on at all. Dealership reconnected the air box.
Tl contact owns a 1999 Hyundai Sonata. While driving 35 MPH, the wheel detached from the vehicle. The mechanic stated that the engine cradle corroded and rusted into two pieces, which caused the wheel to detach while the vehicle was in motion. The VIN was unknown. The failure mileage was 125,000.
Engine complaints in other Sonata years
Frequently asked questions
How common are engine problems on the 1999 Hyundai Sonata?
NHTSA has 28 complaints about the engine & cooling of the 1999 Hyundai Sonata, 16% of the model year's 170 complaints. The component named most often is engine › gasoline (8 mentions).
Is there a recall for 1999 Hyundai Sonata engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Hyundai Sonata, though it has 4 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 Hyundai Sonata engine problems start?
Half of the complaints with a recorded mileage happened before about 89,000 miles.
Is it dangerous?
Owners linked 3 crashes, 1 fire and 4 injuries and 7 deaths to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.