Last time I had P0014 the timing chain was slack



That and front guide was broken

 

Wonderful. What about the fact that it goes away when clutch is pushed in? That and this issue only began after my clutch was replaced (probably should've mentioned that sooner but I just remembered).

 

Well, then maybe has something to do with the new clutch. Take it back to whoever did that job. In the mean time replace the VVT valves to fix P0014, that will cause traction and ECT warnings.

 

Hopefully it's just the clutch, because other than the knocking sound (which also only happens when clutch is out and the trans is in neutral), the motor runs fine. No misfires or loss of power or weird noise while driving. Also I just replaced the VVT solenoids about a week ago, guess that's what I get for not getting the genuine GM ones. Looks like it's back to Advance Auto for me lol

 

P0014 could be the exhaust cam phaser but also could be a malfunctioning or clogged valve the the exhaust VVT solenoid valve assembly. Worth a try, cheap and easy. Use the AC Delco part.. May have nothing to do with the knock but P0014 must be addressed. Look for metal shavings on the screen when you change it. Any chance oil changes were deferred in the past?

 

Checked for metal shavings when I replaced the solenoids a week ago. There were a couple of solid black specks on each solenoid, maybe 2 or 3, but no silver metal shavings. Oil was changed immediately after getting the car, which was sitting for 2-3 years prior to purchase. No clue how the previous owner maintained it, but considering all the other problems it has, I doubt he was good to it.

 

All of that sitting can result in sludge. You might get away with just soaking the VVT valves in oil solvent.