For anyone who owns a 2014 or 2015 Malibu or Impala with the 2.5 liter (LKW) engine:
You want to replace the variable valve lift solenoid now before it costs you a lot of money.
Here is how I found that out:
So, the LKW version of the 2.5 has both variable cam timing and variable valve lift. They are controlled by three solenoids. The solenoid that controls whether it's high or low lift has some issues, mostly that it comes apart and throws bits into the cam cover. These pieces can't be retrieved but cause the system not to work if the cam cover isn't replaced.
I recently bought a 2014 Malibu that had a P16D0. It had 105,000 miles when I bought it, not sure how long it had the code. When I removed the solenoid it had barfed pieces on the passenger side. I was able to fish some out with a magnet and dental hook but the check ball was gone. It was also blocking a passage. Great.
I shopped around a bit online until I found the best "to the door" price, but it was still $400 for the new cover.
I installed a new GM cover, a Dorman 916-806 solenoid (every GM dealer in the universe is out of stock for 12633613) and it's working fine.
To compound the issue, GM doesn't have the parts in stock and the aftermarket ones are hard to find. They pop up here and there at different auto parts places so keep an eye out.
There is a TSB covering this repair:https://static.nhtsa.gov/odi/tsbs/2019/MC-10156918-9999.pdf
I also have a 2015 Impala with the same engine that is getting a new solenoid as soon as I can find it. The cam cover is quite expensive although not hard to replace.
If you have one and replace the solenoid, make sure it's intact. If not, your new solenoid will not fix the problem and might actually make the car drive worse.
There are rumors on "the interwebs" that a redesign is in the works, but I'm not willing to wait until I have to replace the cam cover to find out.