I inherited my wife's high mileage Sonata and have noticed two issues with it I'd like to ask about. First a little info about the car. It's a 2013 Hyundai Sonata with the 2.4L 4cyl automatic and 186,000 miles on the clock. Car runs pretty well except for two acceleration issues. There are no codes present when tested.
Once the car warms up to operating temp there is a noticeable hesitation when you hit the gas in any way except a gentle rolling into it. So if you hit the gas at the green light you're going to get a decent hesitation before it accelerates.
The second issue is I'm noticing a pinging that sounds like pre-ignition (or spark knock) on mid to hard acceleration. I have not tried to up the octane, it says 87 so I've been running 87, so I'm not sure if that would help. However, with gas prices going up I'd rather try and fix the issue instead of putting an octane bandage on it.
Any idea what I can do to fix both issues? Other than those issues the car runs great and gets stellar gas mileage so I'd like to fix the issue and continue driving it.
The ignition timing could be too far advanced. You can try premium fuel or changing out to a new camshaft position sensor (about $25 everywhere). If these don't help, it's time for a new timing chain kit.
How old are the fuel filter and air filter? Is fuel pressure up to specification? What does freeze-frame data while accelerating look like?
Have no idea on freeze frame data but all filters have been changed when due, every time. Only real slacker on maintenance was tranny fluid change, which I can't see affecting the acceleration so I didn't bring it up. I guess I could check fuel pressure. Wouldn't that affect more than just initial acceleration when hot?
Any idea which camshaft sensor usually goes bad, intake or exhaust? My guess would be exhaust just because it's harder to get to. 🙂