NEED HELP Timing chain replacement won't line up with camshaft phaser?

THIS

Original poster
Member
Jul 24, 2019
2
USA
I have a 2012 Traverse LT (3.6L VVT). Twice in a year I've been in this engine to replace the timing chain, but that's what the mechanic swears is wrong with it (misfires like crazy even after brand new plugs and coils). I'm just not seeing the obvious signs of damage/wear like I did the first time, but one thing is bugging me. When I put the last chain on (secondary, right side), the colored link is just off from the marked tooth of the Exhaust cam phaser. Everything else on all of the chains are lined up the way they should.
PXL_20230424_231759004.jpg
I can rotate the phaser clockwise slightly, and line up the chain. As soon as I let loose of the wrench, it slips and the phaser returns to where it was (I'm assuming some type of tensioner inside). The first time I did this job, I was able to hold the chain in place until I installed the rest of the hardware (tensioner and guide), everything lined up, so I called it good. This time around, I'm running into the same thing, so I'm second guessing...is that abnormal? Could it be contributing to my problems? I'm afraid to put this back together again just to need to pull it right back apart because I didn't fix the problem.

The first go at this, I replaced everything with the Cloyes VVT kit. So, new cam phasers, new chains, new tensioners, new gears, new gaskets. This time, I just did the AC Delco kit with chain and tensioners. And to be clear, once I hold the chain in place, and install the guides and tensioners to prevent the chain from moving, the sprocket stays put. But I know that the chain is preventing the sprocket from snapping back to where it wants to, and I can't help but wonder if that adjustment is somehow throwing off the timing once the engine is running. But I don't know enough about that to say for sure.

Anyone run into this before? Am I just overthinking this? Thanks for any help, I'm in limbo until I figure this out...
 
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mrrsm

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Oct 22, 2015
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Check your Work against what you see develop in these Three Videos. The "Hands-On" SME here is @m.mcmillen and there are a few other threads that touch upon this Odd V-6 Engine. You will NOT find Better Instructional R&R Videos than THESE:

TRAVERSETIMINGCHAINMARKS.jpg




Melling R&R Kit Instructional Video:


PS... The Three Component Cam Flats Holder Kit for the GM 3.6L V-6 Engine is ONLY $30.00... so BUY them over on Amazon ...and make this Task a WHOLE Lot EZR!
 
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m.mcmillen

Member
Apr 29, 2016
554
Wisconsin
You should be able to rotate the cam itself, not just the phaser to get it. Looks like you’re only one tooth off. There’s some cam holding tools for that engine that I usually use. You can do it without the tools but they make it easier.
 
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NJTB

Member
Aug 27, 2012
612
Flemington, NJ
I have a 2012 Traverse LT (3.6L VVT). Twice in a year I've been in this engine to replace the timing chain, but that's what the mechanic swears is wrong with it (misfires like crazy even after brand new plugs and coils). I'm just not seeing the obvious signs of damage/wear like I did the first time, but one thing is bugging me. When I put the last chain on (secondary, right side), the colored link is just off from the marked tooth of the Exhaust cam phaser. Everything else on all of the chains are lined up the way they should.
View attachment 107997
I can rotate the phaser clockwise slightly, and line up the chain. As soon as I let loose of the wrench, it slips and the phaser returns to where it was (I'm assuming some type of tensioner inside). The first time I did this job, I was able to hold the chain in place until I installed the rest of the hardware (tensioner and guide), everything lined up, so I called it good. This time around, I'm running into the same thing, so I'm second guessing...is that abnormal? Could it be contributing to my problems? I'm afraid to put this back together again just to need to pull it right back apart because I didn't fix the problem.

The first go at this, I replaced everything with the Cloyes VVT kit. So, new cam phasers, new chains, new tensioners, new gears, new gaskets. This time, I just did the AC Delco kit with chain and tensioners. And to be clear, once I hold the chain in place, and install the guides and tensioners to prevent the chain from moving, the sprocket stays put. But I know that the chain is preventing the sprocket from snapping back to where it wants to, and I can't help but wonder if that adjustment is somehow throwing off the timing once the engine is running. But I don't know enough about that to say for sure.

Anyone run into this before? Am I just overthinking this? Thanks for any help, I'm in limbo until I figure this out...
The colored link is slightly off because of the old chains stretching. GMC Traverse forum has some very good videos on chain replacement.
 

THIS

Original poster
Member
Jul 24, 2019
2
USA
Thanks, all. I have actually watched that go tech video many times when I was trying to figure out how to do this last year. I forgot that he specifically talked about that problem. I actually do have those tools to lock the camshafts down. That's why I was getting snapback when I needed to rotate the phaser. The chains did not seem stretched like last time, so I'm concerned this was pointless. But glad to know the phaser adjustment is normal.
 

mrrsm

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Oct 22, 2015
7,586
Tampa Bay Area
In addition to the clear indication of having a Misaligned ID Tooth on the Right Bank Exhaust Camshaft Phaser... Visit THIS Video ...again, from Mike at Go-Tech ...and assuming you are savvy enough to have access to an inexpensive Oscilloscope; either like the PICO-Scope Two Channel Model #2204A or the more useful and less expensive Hantek Eight Channel Model #1008C Oscilloscope... performing THESE additional DEFINITIVE Comparative Diagnostics might reveal OTHER issues that can also be the causes of Misfires...ON TOP OF the existing Mechanical Misalignment. There really will be no other way of getting down to business without performing these Precision Diagnostic Tests using an "O" Scope:


PS... I'd suggest that you Grab ALL of the On-Screen Wave Forms showing "Known BAD vs. Known GOOD Wave Forms" that the VOP kindly provided here...

More Information about How To Use an Inexpensive Oscilloscope is available at THIS Link:



I'll end here by adding in One Last GM 3.6L Timing Chain Set R&R Video (Practice Makes Perfect and More Practice is Even Better) coming from S.A. Gear Timing Kit Part #76210V:

 
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