oopstoomanytimes

I just changed my timing chain and get the code "Camshaft Position B – Timing Over-Advanced or System Performance"

I don't feel any sputtering
I know I triple checked the marks before and after I pulled the grenade

What do you think are the odds the VVT was bad before and still after the chain job? I surely don't want to reopen it to replace the exhaust sprocket again.
TIA.

mountainmanjoe

post your vehicle info please

oopstoomanytimes

Sorry, I thought I started from the Trailblazer\Envoy section....

2004 Envoy 6cyl 4.2l inline motor.

chem_man

Exactly what Diagnostic Trouble Codes (DTCs) are present? Please post any and all pending, current, and historical codes.

Solutions can vary depending on year, make, model, and engine.

You could be looking at a wiring problem, a dirty VVT solenoid, a sensor, a dirty connector, etc.

Good Luck!

oopstoomanytimes

The only code I get is P0014.
2 days before, I finished replacing the timing chain. I replaced the VVT sprocket also. When I did so, I tripple checked the 3 marks and cranked it 360 after pulling the pin to make sure.
I reset and let it idle for 30 min in the driveway and the code never showed up. Only when I take it for a drive does it appear.

I drove it around town and down a stretch @ 60mph for a few min leading to the code but I don't feel any hesitation, sputtering.

I took a leap and replaced the VVT last night. Letting it run and hitting the gas now and then for a few min, the code doesn't come up. I'll find out later today if the vvt was the problem. I don't want to have to take apart the sprocket again.....

mountainmanjoe

make sure your crank and camshaft sensors haven't come loose
did you check if the chain feels loose? Did you replace the tensioner when you did the chain?
hook up an oil pressure gauge and make sure the pressure is up to spec.

oopstoomanytimes

did you check if the chain feels loose? - no, felt tight. I pushed the chain and see the tensioner moving and bouncing back before closing up the motor. It felt tight- alot tighter than the original.
Did you replace the tensioner when you did the chain? - yes
hook up an oil pressure gauge and make sure the pressure is up to spec- didn't do but gauge looks the same as before.

Will find out tonight if I need to dig more. Start with the easy stuff first....
thx.

oopstoomanytimes

Update: I went on a trip yesterday and ran a little test.

When I got to highway speed I reset the computer and drove for 45 min straight with no code. As soon as I exited and in a min, got the code.

When I got home, with car at idle, I disconnected the VVT and the motor ran fine.

So is this correct: VVT activates only in higher rpm, right? If so, this makes me think the VVT sprocket I got is the problem and indeed "sticks" at advance and not retracting back to idle.

mountainmanjoe

oil pressure is absolutely critical to VVT systems.

It's not and on-off switch. VVT is more of a "dial" that gets turned up and down. But yes generally over 2,000 RPM.

With a good diagnostic tool, you should be able to command the VVT system, and read the camshaft position to see if it's responding correctly.

chem_man

Also, make sure that you used a quality 5W30 motor oil. Doesn't matter if it is conventional, synthetic blend or full synthetic. Just use an oil with an API rating of SN or better.