2017 Kia Sedona 3.3L P0018 130,000 miles (No complaint of drivability problems)

First I just want to say that I mostly work diesel engines and haven't messed with dual overhead cam engines in a while. 

This is my wife's uncles vehicle. 
He tells me this code came up just a month ago right before he took it to Kia for the oil change (May 15th) They stated that the oil level was low and they recommended an engine flush with BG product with oil change. 
Her uncle then told me the the code came back almost right after he left Kia after the oil change. I looked at the van yesterday and found that the oil level was 2.5 quarts low and the only code pending or stored is P0018
I left the oil level low while I did my initial checks so I could compare those to when I put the oil level back to the full mark.
My checks:

First I went into scan data and viewed the desired and actual of all 4 cams at idle. All 4 cams where were at zero as expected. I then ran the control valve test. you can hear all 4 of them click and when engine is idling all 4 work as designed. I did this test multiple times but never caught one not working. 

looking at scan data again, this time just the intake cam on bank 2. I started to notice something. At idle, and I can get it to do it more just off idle, the intake cam actual position would jump up. Sometimes 2 degrees and sometimes as much as 15 degrees. when this would happen I would see the phase command percentage go to 100% to correct it. I unplugged the connector that has the 4 wires in it that go to both intake oil control valves and then I couldn't get it to jump around again. after I plugged it back in and did a key cycle the engine would have to run for a little bit before it would start doing it again.

Next I backprobed both cam sensors and monitored them on my scope. (I haven't been able to get my hands on a known good yet) but what I found was, intake and exhaust cam signals match up with each other while at idle and just off idle. When the intake actual position starts jumping around I can see a distinct difference in the position of the cam signals. And the intake cam signal is not dropping out. 
Seeing the intake cam signal move tells me that the cam is actually moving out of time. And that it isn't a sensor problem.

While doing all this I was clearing the P0018 code and could get it to set again pretty consistently while just sitting in my garage.

After all this I cleared the code again and then added the 2 quarts of oil it needed and redid all the test. 
I never seen the cam move out of time again. 
Then I took it on a test drive for about 20 minutes. then pulled over and shut the car off. Waited a few minutes and then drove back. I did this to get at least 2 key cycles in. Code never came back.  Great!!! It's fixed it just needed oil!!!

1 day later..........

Her uncle calls me and tells me the check engine light is on and the oil level is still on the full mark. I went and checked the codes and the p0018 is back.
And monitoring the bank 2 intake cam I can see the same random jumping around.

My questions:

1. Can an oil control valve cause this? I can't explain why an oil control valve would cause it to randomly move. Or was unplugging it causing some default strategy that was masking the problem and that's why I never seen it move while they were unplugged. When I added oil it did seem to fix the problem for a little bit. 
2. Could this be a sheared pin problem on the phaser on the front of the cam? This seems like a likely culprit. But if it was I can't imagine I could have drove it that long without ever setting a code. And he drove it for almost a full day before it set right as he was getting home.
3. Could this be a slack chain problem/ jumped timing? Until I get a known good waveform I feel like this is the least likely at this point. I feel like if the timing jumped There would be other codes associated with this and he would have drivability problems and possibly misfire codes.

Im trying to find a way to prove what is bad before I have to start taking stuff apart. it sucks that the whole valve cover has to come off to check timing.

If anyone is interested in helping on this I would greatly appreciate it. 

Thanks again 

Kerry

Hey kerry.kozma! While researching P0018, I found this known good cam/crank waveform in Kia service info:

 

For giggles, I also looked up the code set criteria. It's oddly depending on engine oil temperature. Found that interesting! No other manufacturer (that I know of) changes their cam/crank failure thresholds based on engine oil temp.

 

1. Can an oil control valve cause this?

It's possible? But wouldn't be my first suspicion. Normally, I see VVT solenoids either fail electrically, or stick open. The timing behavior you're describing is much more erratic than that.

Unfortunately, the parts catalog indicates that the left and right intake solenoids are unique. Otherwise, I'd say you could swap solenoids bank to bank and recheck.

2. Could this be a sheared pin problem on the phaser on the front of the cam? This seems like a likely culprit.

Agreed. I know you're not excited to take stuff apart, but at least your fault is for the front bank of the engine! If the cam/crank waveform lines up, I'd say it's time to take the front valve cover off and put a wrench on the cams. If you can turn the intake cam more than a few degrees without the sprocket/chain moving, you've found the problem. Compare to the exhaust cam if you're in doubt.

But if it was I can't imagine I could have drove it that long without ever setting a code. And he drove it for almost a full day before it set right as he was getting home.

Not on this engine, but I have seen on other Kia/Hyundai products where the phaser lock pin wears a groove/slot into the phaser housing over time. Eventually, when the engine is hot enough, the clearance between the phaser and the pin opens up enough that the pin can no longer lock the phaser into the parked position. Those vehicles only faulted during closed throttle decel after a long test drive.

3. Could this be a slack chain problem/ jumped timing?

I wouldn't suspect so, but you can still check against the known good.

As Tyler I have seen the lock pins working their ways through the phaser on different Kia and Hyundai engines.

Thank you very much for the reply!!! And the great info you provided.
First, can I ask where you found that known good and the code setting criteria? Searching for the P0018 Kia and all I found were 3 minute YouTube videos with the guarantee I can fix that code in 5 minutes lol.

I did assume the intake and exhaust should line up so at least I got that right.
Im going to check it again since those cam sensors are easy to get to and make sure they are and then see if I can see the intake cam timing shift again when I see it changing in scan data.

With what you provided I think that is enough for me to double check my work and now feel comfortable taking that valve cover off. I just hate taking stuff apart until I can prove that I need to.

While I warned him of the potential problems that could happen if he continues to drive it, I probably won't be able to get it back from him until mid July when they leave for vacation.
Im just letting you know because I am going to report back here what my findings are once I get into it again so if you don't see nothing from me on this for a little bit that is why.

Thanks again for taking time to do that research. It means a lot man. And again, if you could let me know of any sites you found that kind of info in that would be great.
The Mitchell I have only gets me to about 2015.

I agree. Im going to double check a few things but im planning on having to remove the valve cover to check that phaser.
Thanks for the reply!!

Finally back from Mexico City and got the van back over to my house.
His kid was driving it while we were gone and now complains of a low power problem.

I scoped the timing and found it looks like the intake cam has jumped 3 teeth.

I took this capture with the intake and exhaust oil control valves unplugged and the variable intake solenoid valve unplugged for bank 2.

He asked me if he could get just that bank fixed and I told him he needs to replace all the timing components because the engine has been ran low on oil for so long.

Just want to say thanks again for info!! You guys are amazing!