donbrew

In other words, no. It means that the 2 ends of the chain are not reading the same positions; the crankshaft is at TDC but the camshaft is at TDC+1 degree. Yours may be just starting to be out of spec, and warning you of imminent failure.

Technically they are VVT valves, the VVT actuators/solenoids/phasers are on the cam sprockets.

Confusion of the nomenclature is rampant, mostly the terms have become interchangeable.

The valves control the flow of oil to the actuator/solenoid/phaser causing them to hydraulically advance-retard the valve timing. They have to do with the camshafts.

Conax

Quite a system. Rj-Rs mentioned a stretched chain.
That would be my guess. It is an SS so it has probably seen more stress in 100,000 miles than a 2.2 normally does.

donbrew

Well, dammit; I just wrote a treatise that didn't post! And now it is there!

P0016 means that the position of the Exhaust cam is not the same as the position of the crankshaft.

To answer your next question; imagine 1 driven sprocket driving 2 free sprockets then loosen the chain a bit. The "pull" (intake) side will be tight; the "push" (exhaust) side will be off a hair. The slack will be on the "push" side.

It is possible that replacing the chain tensioner will buy you some time, and is cheaper and easier than replacing the chain. But, with risk.

Conax

I'm sorry for intruding on this one, but I find it intensely interesting.
I'll shut up and read.

m_ridzon

I recently replaced the exhaust solenoid, so no issue there. And this weekend, I pulled out the intake and tested it with B+. It worked perfect so no issue there. As mentioned by another contributor, the codes for actuators are P0010/11 P0013/14, which I don't have.

I can pull the valve cover and glance at the chain. What are some tell-tales that I should look for? I don't imagine I will find it sloppy like a noodle since the tensioner may take up most of the slack. But is there a tolerance on how much slack is permitted? Will there be any other obvious, visual tell-tales?

Considering the price, I am kind of leaning towards replacing the crankshaft and intake sensors, have them re-correlated, and see what happens, before diving into a chain replacement. I understand there's risk in prolonging a worn out chain. But perhaps it's not worn out yet and I instead have a bad sensor. If the CEL stays off after the sensor replacements, I would conclude that the chain and tensioner are still doing fine. Agreed?

M Ridzon

donbrew

Hall effect sensors don't go bad very often.

I would try a new tensioner https://www.chevyhhr.net/forums/how-...-rattle-46159/

But be aware that is probably a temporary fix, it may last a long time.

If you can see a sag between the sprockets it is loose.

m_ridzon

Thanks for the link. Hmm, I better revisit my plan forward. I have the "cold startup rattle" that was mentioned in the link. To date, I've just chalked it up to a menial nuance of this new car that I was unfamiliar with. But now I think it's a tell-tale to the chain issue. I'm going to pull off the valve cover and inspect for slack in the chain. Are the nylon guides also visible for inspection once the valve cover is off?

M Ridzon

donbrew

No, but they need to be replaced with the chain, Kits usually include guides and the oil spigot. I don't remember what year they redesigned the oil spigot.

Oldblue

It's usually the front black guide breaks or the upper bolt for that guide.
Check which tensioner you have the one with the hump is the new style

m_ridzon

I've done timing belts before and a general rule for them has been 60K miles, unless published otherwise. What is the lifespan of these chains? I assumed one might last longer than 100K.

I'm going to remove the valve cover this weekend to inspect. Does it have a reusable gasket or should I have a new gasket on hand before taking the cover off?

How much more work is it to replace the whole shebang (chain, tensioner, guides, etc.) versus just the tensioner? Are special GM tools required (e.g., some goofy socket to remove a certain special component)? And do folks typically replace other components while doing the job (e.g., waterpump, engine seals, etc.)?

Thanks,
M Ridzon