Hard start taking 2-3 maybe 4 seconds?

Does the engine make a rattling sounds at idle? If so the timing chain and guides can need to be replaced, to me I would start by serving the throttle body. If it is dirty it can cause a hard start condition. Also, are there any codes in the system? Here is a guide to help check.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is a guide to help you service the throttle body, also keep an eye out for a leaking vacuum line while you are in there.

https://www.2carpros.com/articles/throttle-actuator-service

Here is how the job is done on your car. I would try this first before, can I ask if the engine has low power? This can be a sign the high pressure fuel pump is going out. Read the guides before you begin. Check out the images (below). Please let us know what happens.

The only code is the camshaft crankshaft code, I don’t know if the throttle body is dirty, how can I check that?

The code is P0016 but as I stated I did change the camshaft and crankshaft… I’m going to check the throttle body if it’s dirty, the throttle body won’t move freely if it’s dirty and it will be visibly dirty right?

Yes, I believe if you go into the guide, it will show what a throttle bore that needs to be serviced looks like. The code P0016 is the clue as well. If you already replaced the sensors and you still have this code it means the VCT is not working due to dirty or low engine oil, a bad oil control valve or VCT unit or the timing chain set including the guides are worn out. Does the engine make a rattling sound at idle? Can you upload a short video of the engine idling so I can hear it?

Here you go, I cleaned the throttle body and did the relearn method for the position sensor. Still does the same thing…

Sorry, you must have a new iPhone, the site has not been updated to see this file, can you change it on your end? The site takes all other video files.

Try this one maybe? It’s from files.

I don’t know what you mean by change it from my end??

Do you have an email I can forward the video to? The sites seem to not be accepting or loading the video up. I have an iPhone 16 pro max that I just got, I don’t know if that pertains to updating the site?

Correct, Apple keeps updating the files we can upload so we have not done that yet, the phone is too new. I think there is a setting inside the phone and can switch back to the old apple files which we can see no problem.

I still don’t understand what you mean, do you have an email I can use to send them to?

Check it out:

https://youtu.be/ssXPAm7ZZgo?si=SKPTZp6bz7OuuEDc

Let me know

Oh you’re talking about the format of the video itself not the website… so the website only takes HEVC formatted files or JPEG?

Try this one maybe.

Nice work! yes thanks for the video. Yep, the rattling sound is the timing chain system, this means the timing chain, guides and camshaft actuator need to be replaced much like I suspected in the first post. The only other thing I would try is cleaning the throttle body.

Thank you, so I did clean the throttle body but the actual timing chain has to be replaced? The guides? Camshaft actuator or is it one of these that’ll fix the problem?

Another thing, what are the parts you’re referring to? It’s the whole timing chain? What “guides” and I also cannot find the camshaft actuator?

Yes, here are the parts I am talking about, can I ask if servicing the throttle body did any good? You can remove the valve cover to check the timing chain "play" to help confirm the issue. Also, make sure the engine oil is clean and full. The camshaft system depends on this, sorry I didn't mention it sooner. Let me know if you need instructions to do the job. Check out the images (below). Please let us know what happens.

So cleaning the throttle body helped for about 2 full starts then returned to its original shape and performance. Engine oil has just been changed about 3-4 weeks ago but this engine does eat a lot of oil somehow and I’m having to refill 1k miles before the original change date or mileage required (3k). Also, removing the valve cover, will I be able to look right at the timing chain without removing any other parts? I have done so on a jeep compass before so I know how to get in there… camshaft system is what specifically? I changed the camshaft sensor aswell as the crankshaft sensor but in the video that I have sent you can see that oil and smoke spews out of the oil dip stick hole when I took it out. I’ll try to look into the timing chain thing but another thing is I heard some people say that when an engine gets replaced via a recall, Kia will use the old parts for the new engine which can mess up the timing chain aswell, is that a problem?

The valve cover will need to be removed to inspect the timing chain. I would go over everything in this guide before digging into the engine.

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

You may have low fuel pressure.