2011 buick lacrosse 2.4 P0014

2011 buick lacrosse. 2.4 returning p0014. Previously customer had replaced exhaust an intake camshaft solenoids, intake cam sensor. Changed the oil. Followed diagnostic procedure with little to no help. When commanding exhaust camshaft actuator the desired changes with actual degrees. Scopped the pulse with modulation on the exaust actuator and found that it drops out randomly. Thats when the desired exhaust dregree changes from actual. Command percentage fluctuates from 0 to 73 with no change in actual green is exhaust camshaft pulse width modulation and yellow is camshaft signal on exhaust side. Intake side has continuous 12v pulse width waveform. Exhaust side cuts out requardless if plugged in. When the continuous signal returns i can control desired exhaust camshaft angle

Sounds like a cheap dorman solenoid. Your scope shots aren’t uploaded on here

I uploaded some

The scope shots are fantastic! But the variance of five degrees tells the story. The PCM commanded a cam timing change and didn't get it. The dropping out that you're seeing in the pulse width waveform is the PCM desperately trying to get the cam timing to change. :lol:

IMO, you're down to a stuck closed solenoid, or a failed actuator (the actual phaser on the camshaft itself). You can check for a stuck solenoid by applying direct power and ground (briefly) to the unplugged solenoid and listen for a solid click. Or, you can use an amp probe to check for a pintle hump.

Either way, if the solenoid checks out, then the engine is coming apart. Individual actuators CAN be changed with just the valve cover and the primary timing chain tensioner removed, but it's sketchy. :silly: A whole timing set, including the balance shaft chain, is the better option.

Thank you, its been a busy week. What i forgot to mention in my primary post is that i did apply direct 12 volts to the solenoid and watched the pintle move. And because i have had new parts fail multiple times i did try putting another actuator in with no success. The engine is a junk yard engine that was installed a little over a year ago. My next thought was to check for movement in the camshaft phaser but i would have thought that it would throw a crank cam correlation code. What is odd is that after the engine runs a while the variance drops to 0 and when it does, i am able to control the solenoid with the scan tool.

Hi everyone,

Have you check for any oil pressure fluctuation?

I have seen these ecotec engines with metal chips (upper chain tensioner) and internal oil leaks (chain tensioner o-ring).

I have also seen broken parts (chain guides and chain tensioner). Even with no codes.

I would check for any correlation between oil pressure and angle variation.