There is a knocking sound in my engine

You lost oil pressure, either due to oil loss or oil pump failure. When this happens the crankshaft bearings lose lubrication, heat up, expand, and freeze, or seize the engine. This is called lockup. The Kia folks lied to you about the safety of driving in this condition, or they didn't understand your description of it. Loud knocking inside the engine calls for immediate shutdown to avoid catastrophic damage. You are now looking at at least and engine rebuild, if not a full replacement.

Henry, first need to determine if it's the actual engine that is knocking. Other accessories (water pump, steering pump, etc) could cause a knock. If the ECM knock sensor picks up a knock, regardless of where it originated from, will start to make timing and fuel adjustments which may cause it to hesitate or "sputter". You can take off the drive belt and start the engine. This will be the tale. If you hear the knocking, it's obviously in the engine and could be as bad as crank bearings or even the torque converter. Have you had any work done recently? If there is no knocking when the engine is running without the serpentine belt, you should now be able to narrow down the bad component by rotating each drive pulley until you find the damage..

Sounds like a rod bearing knock.

Sounds like a tapping maybe lifter. Maybe valve check under valve cover.

Well lift the car up and put it on drive wile you can hear what the knock is. See if is your engine or the transmission. And if ok check your spark plugs make sure you getting fire to them

You have a rod knock. Do not drive this car until you have this looked at by a professional. Drive this car and the engine may self destruct.

If this sound only happens when you first start it in the morning, and then goes away, then you are experiencing either lifter ticking, or piston slap. These both are fairly normal for this vehicle when it's getting higher in the miles, and before the oil gets to all the parts. Once you shut the engine off, the oil drains down, and it has to recirculate some of it. This takes a couple of seconds sometimes, and you hear this knocking sound when it happens, especially if it's cold out, or you are using thicker oil than recommended.
If the knocking sound continues after the vehicle has been running, then you need to have someone check it out for sure, because you could have a connecting rod knocking. This means that your engine is about to go, and you should not drive it.

you have a rod knocking in the engine

Hi,
Good news is - I don't think you need a new engine.

As there are many moving parts that could create a knocking sound, it usually needs careful inspection to identify where it is from.
I will give a list of some of the causes and remedies. Yours will probably be one of them, but unless I was there - it could be any.

Loose exhaust component (causes rattles and thumps) - replace parts or joints.
Loose Engine mounts - Engine will move about a lot more than normal - Replacement of mounts.
Fraying Belts - causes continual ticking or slapping - Replace belts and check tension.
Timing is off - bad running, lack of power, pre ignition or knocking at low revs. Check timing belt - Replace, Tune engine.
Cracked valve - slight misfire worse at low revs - Replacement valves.
Clutch Problems - Broken spring or loose bolt - Check clutch plate - replace clutch plates.
Older engines - often accompanying smoke -
Broken Piston ring - continual ticking or occasional misfire - Replace Piston rings
Worn Piston bearings - Piston Slap - Replacement of all piston bearings.

Transmission Problems (only heard when in gear or with clutch out) - Broken gear teeth or worn bearings - Replacement of Transmission or rebuild.

Some of these remedies require engine removal and strip down, others are a simpler fix.

The idle issue is normal. The idle is controlled by the ECU. There are no adjustments for the idle. Regarding the knocking noise, that could be several things, and I am hesitant to comment without hearing it. Take it to a Toyota Dealer & have a tech listen to it. We are very good at identifying noises on the service drive.