2008 Hyundai Sonata: adaptive cruise control problems

Filed Apr 25, 2025 · Engine, Transmission · VA

Bought in 2023 @ 98k miles. Have had trouble with 1.it would only start in drive, then that seems to have self corrected. 2. In drive, car would not accelerate properly, and would slow as though I was braking, but no foot on brake. Had rear brake sensor replaced, seemed better for a while. 3. Developed oil leak at 120 miles which valvoline characterized as "not serious...just keep checking it and topping it off." So, have been doing that. Today after oil change, it began running rough, lots of vibration, then the shifting problem, sluggishness, and new..smoke from under hood on driver's side. No check engine lights at all. Nothing registered as hot or overheating. Turned off car, checked oil and trans fluid, both in proper range for warm engine. Let car sit and cool for an hour. Decided I had parked too close to the propane tanks for a smoking car, so I decided to start car just to back it into a space across the lot. Car had no issues- No smoke, no jerking or vibration, no sluggishness, no phantom braking. This car has done this same thing about once every 6 months since I've had it. Changed a tire sensor, that seemed to fix it once. Stopped using cruise control altogether, that seemed to help once. My brother is an ASE certified high school auto mechanics teacher who ran his own shop for 20 years and worked on trucks for VDOT for another 7 years and he cannot diagnose it. I know it has something to do with not being in the correct gear, but it's not reliable, and I have a hard time believing it's just my vehicle.

Filed Dec 23, 2015 · Steering · 64,000 miles · PA

12/23/2015. 2008 hyundai sonata gls. Steering wheel locked while the vehicle was in motion this evening. I was driving on secondary streets in town at a speed of approximately 30mph when the steering wheel locked and would not turn while negotiating a very slight left hand curve in the road. I braked with intent to attempt to pull over and the steering unlocked and started moving freely again. I had made a 90 degree right hand turn about 1/4 of a mile prior to the steering locking up and had no problem or tightness in the motion. Cause for the incident is unknown. I was not using cruise control, anti-lock brakes were not in use / activated. We did not experience any significant bumps in the road. We reached our destination without further incident and made the return trip also without incident. No police report or insurance claim has been filed yet as of the time of this post.

Filed Sep 12, 2014 · Engine, Transmission · 143,056 miles · CA · fire

Driving while using cruise control at approximately 65 MPH the check engine, air bag, and e.s.c light illuminated. Also, a simultaneous internal engine explosion resulted in an instant fire as well as a rod thrown from the vehicle damaging block and setting the car on fire from a resulting massive oil leak. There was no prior damage leading up to the incident nor any indication to my knowledge that there were any concerns with my car till it was too late unfortunately.

Filed Jul 16, 2014 · Acceleration, Brakes · 60,000 miles · CO · crash · 1 injury

I was driving south on i25 in colorado near denver. The car was on cruise control, going approximately 55 MPH. I saw a bus a couple of hundred yards away. The bus was either stopped or going very slowly. I applied the brakes and my 2008 sonata would not go out of cruise control. I tried canceling cruise control and braking and car remained in cruise control. At the last moment, I tried the emergency brake as I crashed into the back of the bus going about 55 MPH. I nearly died. I couldn't breathe for 20 seconds. I have fractured ribs and fractured bones in my back. The car is totaled. It looks like a squashed accordion.

Filed Oct 29, 2013 · Lights, Visibility · MD

2008 hyundai sonata. Consumer writes in regards to vehicle problems shifting into reverse or park and faulty brake light switch . *smd the consumer stated her son drove the vehicle to school, and when he tried to straighten the vehicle, he discovered that it would not shift into reverse or park. Her son had to get assistance, to push the vehicle out of the parking space, so he could shift into drive. Her son was able to drive away, and while driving, it became apparent the cruise control was not responding normally by disengaging when he applied the brakes. He immediately drove to an auto center. The auto center determined the brake light switch was faulty and replaced it. The consumer stated shortly after purchasing the vehicle, she began having problems with the bower/fan switch, which would operate intermittently. After several visits to the dealer, they finally replaced the fan on december 6, 2011. On or about july 2012, she again began to experience the blower/fan operating intermittently. The dealer offered to do a diagnostic test to determine the problem. However, the warranty had expired by one week. Updated 11/25/13

Filed Sep 7, 2010 · Acceleration · 30,000 miles · OH

I had a terrifying experience and near/miss this morning. My 2008 hyundai sonata (limited edition) car suddenly accelerated for no reason as I was exiting an expressway doing 65 MPH! I couldn't stop the car! My foot was slammed on the brake and I felt/smelled the brake, but the car kept accelerating. I flew through a stop sign at the top of the exit ramp, blowing my horn, whipped around the curve to a street on the right, nearly hitting 4 cars before I finally threw the car into neutral. My car has cruise control, but I don't use it. I was very shaken up, but miraculously, no accident. I had the vehicle towed to the hyundai dealer, and the technicians cannot find anything wrong with it. I won't drive that car again in its current condition. No way. I was terrified. This was clearly a case of sudden unintended acceleration. Nothing like this has ever happened to me before, and I've been driving for 30 years.