I'm hoping I can get some advice. I'm currently doing the timing chains on an 09 CTS with the GM 3.6 vin 7.

Relatively far along in the process - when reinstalling the first chain using the L marks on the cam phasers and the colored links on the chains there was maybe about half a tooth that the chain needed to go in order to seat on both phasers. I gave the cams themselves locked using those plates (I don't know the proper name for them) at the back. When pulling in the chain to try and get it to seat correctly the left cam phaser made a clicking sound and rotated clockwise about the distance of one tooth.

Now if I use the marks on the cam phasers and on the chain there's a significant amount of play/slack at the top of the chain.

My question - is it possible to reset the position of the cam phaser, do I need to remove it and reinstall? If so how do I ensure it's oriented correctly with the cams so that the timing is correct. Also am I looking at a failed cam phaser? I've done several timing chains in my life but this is my first one on a high feature engine. Any advice is appreciated!

 

If the timing marks are still lined up, install the guides and tensioner (all bolts snug just for testing/inspection), remove the cam lock, and see if the chain tightens up.

If it tightens up, rotate the crankshaft 3-4 times (you may need to remove the cam locks on the other bank to allow piston-to-valve clearance) to check the timing & cam-vs-phaser movement. The cam & phaser should move as one assembly (reference marks with a paint stick or white out will help spot movement).

If the cam & phaser are moving independently, get a new phaser. If not, reset everything to the correct timing positions and continue assembly.

And make sure to remove the cam lock when installing the phasers/timing chain - the cams have a hex molded into them so they can be slightly rotated for timing component installation.

 

Thanks so much for the reply!

With the chain on you can see from the pictures that of the chain is on the proper marks, hard to see but marked with yellow paint pen) there's a lot of slop at the top. If I move it one tooth over the it sits how I expect it to look (just minus the marks being lined up)

To make sure I understand what you're saying - snug up the tensioners and give it a few rotations to see if the slack comes out of the top of the chain? I would only expect it to be able to tension slack out of the side but that could be my limited understanding. I'm wondering if it doesn't take tension out how I'm going to reset timing to the proper position since the marks will be misaligned already.

Thanks again for the help! I'm doing my best not to make the situation worse 😅

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Chain marks and cam phaser marks lined up - chain is loose up top.

Chain marks one tooth off from phaser marks - This is how I would expect the chain to sit.

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Keep in mind the cams are positioned to provide minimal tension on the chain as the timing components are being replaced.

The reason the slack can’t be adequately assessed without the guides & tensioner is because of the possibility that the actuator may not be in its at-rest (deactivated) state - whether that’s due to damage or the position of the cam relative to the actuator gear is what needs to be determined.

Once the guides and tensioner are in place and the cam lock removed, the cams will rotate slightly in response to the pressure from the valve springs and take up all the slack that shouldn’t be there. Rotating the engine by the crankshaft will then allow the actuator to fully return to its at-rest position.

If there’s still excessive slack in the chain at that point, it’s likely the actuator needs replacement because it’s not returning to the at-rest state.

Here’s a few pics of an actuator I removed from a 2011 3.6 to give you a better idea of what you’re trying to determine.