ajparry89

Hello, I have been working on my 2009 Equinox 3.6L timing chains for a while now chasing down timing chain correlation codes. I replaced chains and phasers and tensioners and guides. my timing is always perfect - ive done these chains many times before. but codes came back (I am sorry, its been a while now I forget which code! Bank 2, intake shaft correclation) I replaced solenoids - didnt do anything. then figured it was bad tensioners (I had reason to believe that) so got some from GM, but that didnt solve it. then, I decided to get GM chains, and in the process I noticed that my new phaser on that intake camshaft had a lot of movement in it when bolted to the camshaft. like you can wiggle it back and forth. B2 intake phaser did it ALOT more than B1 intake phaser. exhaust phasers didnt move at all. I did research and that told me that if they move like that, then the phaser is bad. So I decided to get GM phasers. I installed them today with the GM chains and GM Tensioners, super confident now I found my issue. however, after I put the chains on, I noticed that there is still A LITTLE movement in each intake camshaft phaser - I can put a wrench on the cam and wiggle them every so slightly. My question is, is this normal? Mitchel says to simple torque them and that is it, no other special installation instructions. Ive done some phasers where they need to be locked/unlocked prior to installation. But these do not require any of that, correct? have I done something wrong installing them? or is SLIGHT movement Ok? they definitely do not move as much as the first phaser did. any advice or tips is greatly appreciated!! Thank you!!

Gumby22

Slight movement is normal but it depends on the direction. As viewed from the front of the engine, and using a wrench on the camshaft as you described, clockwise is normal, but counterclockwise is not. The cam is bolted to the inner rotor of the phaser and the chain sprocket is attached to the outer rotor with a spring to maintain an at-rest/default position of keeping the rotor fins in contact (counterclockwise force of the spring.

Installation is as simple as making sure the alignment pin on the phaser is seated correctly on the camshaft and torquing the bolts to spec - IIRC it’s 22 ft-lbs + 90* - make sure to install new bolts if you haven’t already.

If you’re still getting crank to cam correlation codes with new chains and phasers, remove the crank sensor and inspect for a shifted crank tone wheel. Search for GM TSB# PIP3423P for the procedure.

ajparry89

Ok thank you for your help. so if I am staring at the phasers head on from the front of the engine, the cam can rotate very slightly clockwise, meaning towards the front of the vehicle (timing chains are passenger side).

I did also consider that tone wheel issue. however, my crank is also new - had bad bearings also, that was part of this project originally as well lol. BUT, I also read that some cranks, if they are cheap, come with the wheel installed wrong or they shift just like the original.
a better remanned crank will have the tone wheel pinned in place. I suspected that a bad tone wheel would throw codes for other cams as well, not only one, so rather than take the whole thing apart again and waste my time, I literally tracked down the actual manufacturer where my new crank came from and spoke to the head of the company - some place in florida - He has tons of experience with these motors and cranks, and insisted that YES, theirs is pinned in place because of that exact issue that they have. so I dont think that is the problem.

I will double check the direction of the movement, but I am hoping it was just that one bad phaser that I got. I appreciate your insight on that - I couldnt find anybody online speaking about "allowable" movement with a new one after installation.

ajparry89

Ok so when I check the direction of the movement on B2 intake phaser (the bank towards the front of the vehicle), its movement is slightly toward the front, clockwise (towards the exhaust cam). When I check the movement of the B1 intake phaser, its movement appears to be counter clockwise - towards its exhaust cam also. That actually makes sense to me, that both would have slight movement in the same direction in respect to their bank (both having slight movement towards their exhaust cam) but I may not be thinking through the fundamentals of the motor properly haha. If that is not correct, and they BOTH should be CLOCKWISE, is it possible that its simply the tension of the chain at the moment, and way the cam lobes are sitting at the moment, to cause it to APPEAR to be moving counterclockwise, when actually i am just returning it from its forward clockwise movement? oh man, I am making my head hurt now! lol

Gumby22

I think I’m understanding what you’re saying but since I’m not personally seeing/feeling the movement, and for the sake of clarity, here’s what I can tell you is normal when checking phasers.

At rest (engine off, which is also the same when engine is running but VVT isn’t activated), the inner rotor is held against the outer rotor using spring pressure. The cam and phaser should move as a unit until the chain stops the sprocket (there’s always minor slack in the chain with the engine off).

At that point, there should be no further movement of the cam or sprocket CCW, assuming the inner rotor is seated against the outer rotor. It is possible a weak spring wouldn’t bring the inner rotor to a fully returned position but any movement due to that should be minimal; and for operational purposes, that’s unlikely to be a problem or cause a code since the outer rotor continues to rotate and will “catch” the inner rotor, causing it to seat.

If rotating CW, the cam should continue to rotate while the sprocket remains fixed, but it’s been my experience that there’s enough tension on the springs that the whole engine will rotate with the cam, so checking this usually requires a wrench on the opposite cam or crank pulley to hold the engine if CW movement is being checked.

I have a phaser at work that I disassembled after replacement for explaining its operation to customers - I’ll try to get some pics on Monday to post for clarity.

The only other thing that comes to mind for the correlation codes is some of the cams have been known to twist or allow the tone ring for the sensor to shift (much the same as the crank). I’ll have to do some digging to find out the correct positions for checking them - I know the tone ring is checked against the plane of the head, but certain valves have to be fully open for reference and I don’t recall which ones for each bank/cam at this point.

ajparry89

I appreciate all your help! I know its hard to explain all this through typing. although we each have a hard time following everything we say, I think I am getting the gist of it. very slight movement is normal. that is what I have - at rest. when its cranking/running, there will be no more movement. when at rest/idle position, the phaser is locked. the slight movement that I feel is just the wiggle it has within the locked position, I am guessing. This video shows how a phaser goes bad and doesnt lock


that was not the problem that I was having with my first replacement phaser. however, the movement "within the locked position" was very significant, and the other intake phaser only had very minor movement/wiggle, much like the new ones I got now from GM. So I am going to assume that the one phaser that I got was just not good enough, especially since I was coding for that bank and that cam.

If you can send any more info that would be great, although I hope to actually start putting this back together this morning. Thank you!

Gumby22

Well, I apologize for misinforming you on the actuator operation - there’s no return spring for the rotor. I must’ve been thinking of an actuator off a different engine, or possibly an early design. I know I’ve seen actuators with return springs but I can’t recall what the application was.

That said, I would consider a little “wiggle room” between the sprocket and cam to be normal.

Here’s the pics of the actuator I have - this one was an exhaust actuator. An intake actuator would have the locking pin on the opposite side of the rotor gap, as marked, but they both function the same way.






When you’re monitoring live data, regardless of the commanded position, actuator positions should mirror each other bank to bank. If bank 1 exhaust is 10* then bank 2 exhaust should also be 10* - if bank 1 intake is 25* then bank 2 intake should also be 25*.

If no mechanical problems are found with the actuators, cams, or timing, the sensors and control solenoids should be checked. The easiest test is to swap them between banks and see if the code follows.

7Acadia

Hello well it appears I have the exact same issue just installed all timing chains and the works but ending up with a p0018 code which is bank 2 intake cam crankshaft correlation code I remove the valve cover and can't find anything wrong chains are tight cam phaser appears to be normal did you ever resolve the problem on yours? Thank you

ajparry89

I did resolve it, I cant remember the exact order of what I did, but I know i ended up replacing everything including the phasers and used all GM parts. THEN 3000 miles later, the issue came BACK, and it is currently inside my garage torn apart again for like the 4th or 5th time and cant find an issue. assumed tensioners were just junk and it jumped time, so I redid everything with new tensioners which i got warrantied. and immediately upon start up was misfiring bad across the front 3 cylinders again. hasnt thrown timing code yet, as I guess I havent let it run long enough yet. but tore off the front valve cover to again find no noticeable issues.

I am suspecting a bad phaser though on front bank exhaust (my code was originally for that cam, P0019 i think it was) - (even though that is also brand new from GM 3000 miles ago!)
as I rotated the engine, at one point, it caught slack between the phasers, which I didnt think much of, just the rotation of the chains and pressure on the cams, etc, since im turning it slowly compared to cranking. however, usually they catch slack AFTER both cams, not between them. so i gave it another slight turn of the crank, and the cams quickly jolted forward as i would suspect, then my eye caught something that I could not reproduce - on the front exhaust cam phaser, the reluctor wheel/signal wheel on the front of the phaser for the cam position sensor, then seemed to have a delay in it and it rotated forward about 1/4 of an inch on its own AFTER the forward jolt of the cams had already taken place.

is this normal? should that happen? or does that mean I have a phaser that was unlocked/not locking? I rotated the engine a hundred times after that and could not even reproduce the slack between the cams that occurred that one time. ughh!!
Anybody have any ideas??

vh07191952

did you replace the phasers?