16th Nov 2017, 14:41
Yet another small update.
I noticed when stepping into the car, the brake pedal is rather hard to depress. Or, it has to be a little depressed or the Start button won't fire up the engine (this is how keyless start up works on this car). I found myself a few times wondering why the engine doesn't fire up.
Another thing, which perhaps is an issue. The car was parked for a few days, it is near freezing temperatures here. Upon firing up, the engine runs at idle with a little bit of 'miss'. Not really a misfire, but like an hesitation for a few seconds. I wonder if this would be related with the missing coolant in the past. Could it be the engine has an assembling problem with a small leak at the head gasket? If it leaks a little into the cylinders when the car is at rest, that would explain the small hesitation at idle.
14th Dec 2017, 02:43
Tested the Sonata in cold weather, around -7C or about 20F. I can certainly tell that cabin heating is weak on this car. Even with the engine fully warmed up (which takes quite a while) with both heat knobs at Hi, the air is far from hot. What's worse, the vents for your legs blow very little airflow. By the way, the temperature knobs are tricky: you have to keep them turning because they can display as much as 31C! So keep them turning to reach the Hi setting.
Speaking of cabin air, I remember on hot summer days, the air conditioning also wasn't really satisfying; not bad, but it certainly wouldn't keep up with a hot Texas day.
By the way, the key fob battery started to display 'low battery' when the car shuts off; just check out on YouTube how to replace the battery, it takes a 2032 button battery. Make sure to buy a good brand; the original battery is a Panasonic. The battery lasts about 2 years (normal in these keyless entry cars) and goes flat even in the spare key fob that is never used. The Hyundai dealer wants $150 to install a fresh battery and "reprogram" the key fob. The key fob actually needs no reprogramming.