[JLL]

Are you using quality alignment tools? It makes a BIG difference especially when it comes to aligning the phasers.

 

[JLL]

Hello @JLL,

Thank you for response.
Well, I'm using dedicated box for this engine, hard to estimate whether they are good quality or not.

As for me - yes. Let's say I've partialy tested the tool.
I've put the locker only from the exhaust side, and tried to move it forward slowly to side of intake crankshaft. It's blocking on middle of the head (which actually prove that the exhaust camshaft is not perfectly aligned). This is not happening on the intake side.

I'll record video today how it looks so maybe it will be easier to understand.

Meanwhile, can those camshafts position be fixed somehow?
I've unlocked the camshaft on the left side for both, set up all the tools, then I've screw both of them while aligned, but still there is a minimum requirement to push the exhaust camshaft to side of front bumper to put the tool.

To be honest, I've found few videos and guides where people say to minimally rotate the camshafts if it's needed to put the tool, but in most of videos they says it should easily go on it position.

Make sure the cams aren't out of phase with each other.

Other than that, It's pretty much trial and error. You just have to keep removing all the timing tools. Rotating the engine, 720 degrees, lining the crankshaft up to TDC, installing the timing tools.

Also make sure you replace the phaser bolts if you torque them and then have to loosen them.

 

[JLL]

Hello @JLL,

Attaching a video just from now. The rotation is just a milimeter.

Can you take a look? What do you think? I've already rotated it many times, always on TDC this behavior is happening.

It looks like the timing is off by a tooth. The cams aren't both off 180 degrees are they?

If it were my car, I'd take the chain off and re-do it, but I'm a perfectionist when it comes to my car.😆

But I've heard of people being off by a tooth and running them that.

 

[JLL]

Hi Guys,

thank you very much for response, appreciate.
From what I've understood this engine is builded the way that if you use all the tools, and follow replacement steps it cannot be off by a tooth.

Why? It doesn't matter how you put the chain because we are loosen the camshafts bolts and they are freely to align (independently to the chain which at this point is already set up).
It's explained here: How-To: Cruze/Sonic 1.4L Turbo LUV/LUJ Timing Adjustment

I think I need to loosen the camshafts again and try to tighten them one more time. Maybe during tightening them and holding the camshaft with second wrench to not let it move I've just used too much power in holding them and accidentally moved it by milimiter.

I'm afraid to unscrew them for the second time, but seems I've no choice.

If you loosen the cam phaser bolts after they have been torque you will need to replace them. But yes, you will need to do that.

You actually can put the chain on incorrectly. There is enough slack in the chain to skip a tooth. In your video when you try to move only 1 camshaft, you can see that the chain bunches up. That's an indication that the chain is off a tooth.

If the chain is physically off a tooth, the mechanical timing or base timing is off. The variable value timing (VVT) system uses the base timing as a reference point.

To clarify here is an example.
Let's say ECM commands the VVT system to add 20 degrees of timing when the base timing is correct at TDC or 0 degrees. For this example let's say there are 72 teeth on the cam phaser gear. Than means each tooth represents 5 degrees of cam timing. 360/75 = 5.

Actually timing = 0 +20 = 20

But if the base timing is off by a tooth that we said represents 5 degrees, the ECM and the VVT system don't know that. So,

Actually timing = 5 + 20 = 25.

But the ECM is only commending spark advance at 20 degrees because it doesn’t know any better. That can cause partial combustion, which can cause incorrect fuel trims. Then the engine runs rough.

 

[JLL]

Hey @JLL,

such a great explanation, thanks for that.
However I still don't fully understand how chain can be off by a tooth.

In documentation, guides, references there is nothing about any specific way of putting the chain.
Isn't it that the chain can be putted in any way, BUT we need to make sure that the camshaft is properly aligned with lockers on it proper position before torquing?

If not, then how can we put the chain correctly on? Even that guide I've posted above doesn't say a word about it.

You can put the chain on in any way BUT, you have to make sure the chain doesn't shift a tooth when you put tensioner on it. If you have any slack after the tensioner has been released and the upper guide is in place, the chain slipped a tooth, most likely on the crankshaft spocket.

The cam phasers can go on in any direction too.

You just have to make sure when you tighten the cam phaser bolts that the camshafts, exciter rings, and crankshaft are in alignment AND don’t move when you tighten that cam phaser bolts. The camshaft position sensors read the position of the exciter rings to determine what positions camshafts are. If any of those are off there will likely be issues.

The first time I timed a LUV/LUJ I went through 3 sets (6) camshaft phaser bolts at USD $25 EACH before I got it right.

 

[JLL]

Yes. What you are describing is the exhaust camshaft moving slightly. If that happened you're going to have to take all the tools out, loosen and replace the phaser bolts, retime, and then tighten the new bolts. If you are loosening the cam phaser bolts once they are already torqued they will never tighten correctly due to the large torque that's involved. They do need to be replaced since they are TTY. There could also be is a small defect in the timing tool set. That could be the issue too.

The chain can move if there's too much slack in it before it tightens. If you were paying attention and you KNOW it didn't skip a tooth on the crankshaft than it didn't skip a tooth. But I've seen a lot people get into trouble when they don't pay fully attention.

As a side note, You did leave the timing tools installed and hold each camshaft still with a wrench while tightening the phaser bolt, right?

 

[JLL]

Good luck.

 

[JLL]

Hey @JLL,

I think we got this

What do you think about this?

Overall it looks pretty good from what I can see but, if you didn't, you need to tighten the clamps on the exciter ring tool. It can make a difference. You may have done that. I just didn't see it.

 

[JLL]

I've did that during alignment process and for internal test afterwards, indeed didn't do that on video.
I hope this engine will ever start...

Thank you very much @JLL for your advises, explanation and time.
I'll come back here to confirm whether it started or not, probably I'll do it in 2-3 days.

You're welcome.

 

[JLL]

Your welcome!