Hi all,
I bought a used Sonata (2.7L) last week from a dealer (my first Hyundai and my first automatic transmission) and it has about 170kms on it. The timing belt had never been replaced so I scheduled an appointment to have it replaced - I picked up the car from the dealership where I bought it and literally drove it to the service department at the Hyundai dealership down the road.
It took them 4 days (including the weekend) and a few extra parts and hours of labour to replace it - although they did honour their quote, more or less, which was nice of them. I picked it up this past Monday and drove it home. A few hours later, I took it out for a drive and within a few minutes it started to randomly downshift from 4th to 3rd and then back up to 4th. 4th to 2nd and then back up to 4th.
I pulled over and shut off the car and let it sit a minute. When I started it up, the problem had disappeared and didn't reappear until the next day. There is no slipping of the gears, it accelerates normally. The transmission fluid is full, it is the typical red colour and it does not smell burned.
It seems to like to do this around 60km/h while cruising in 4th. It does not seem to do it in manual mode.
I went online and found a youtube video someone filmed of their Sonata doing the same thing:
He seems to think it's a Throttle Position Sensor. He also says that pumping the gas peddle a few times before starting the car helps, and it does actually but it doesn't get rid of the problem.
I've been doing some research and my list of possible problems keeps growing ... Throttle position sensor, vehicle speed sensor, input/output sensors, transmission fluid temperature sensor, transmission solenoid or the worst case scenario, a bad transmission ...
Any help/advice on this is great appreciated!
I bought a used Sonata (2.7L) last week from a dealer (my first Hyundai and my first automatic transmission) and it has about 170kms on it. The timing belt had never been replaced so I scheduled an appointment to have it replaced - I picked up the car from the dealership where I bought it and literally drove it to the service department at the Hyundai dealership down the road.
It took them 4 days (including the weekend) and a few extra parts and hours of labour to replace it - although they did honour their quote, more or less, which was nice of them. I picked it up this past Monday and drove it home. A few hours later, I took it out for a drive and within a few minutes it started to randomly downshift from 4th to 3rd and then back up to 4th. 4th to 2nd and then back up to 4th.
I pulled over and shut off the car and let it sit a minute. When I started it up, the problem had disappeared and didn't reappear until the next day. There is no slipping of the gears, it accelerates normally. The transmission fluid is full, it is the typical red colour and it does not smell burned.
It seems to like to do this around 60km/h while cruising in 4th. It does not seem to do it in manual mode.
I went online and found a youtube video someone filmed of their Sonata doing the same thing:
He seems to think it's a Throttle Position Sensor. He also says that pumping the gas peddle a few times before starting the car helps, and it does actually but it doesn't get rid of the problem.
I've been doing some research and my list of possible problems keeps growing ... Throttle position sensor, vehicle speed sensor, input/output sensors, transmission fluid temperature sensor, transmission solenoid or the worst case scenario, a bad transmission ...
Any help/advice on this is great appreciated!