I picked up a 2009 Pontiac G8 with the 3.6 V6 a few weeks ago and it recently set a CEL for an intake valve timing issue (p0008). The car has 164K on the clock. The code set when it started cold (about 35F that day), and by the end of the day by driving around, the code went away. Then a few days later, another cold morning the code set again and was gone by the end of the day.
Oil was changed with 5W30 synthetic at the dealer when I bought it. I checked the oil each time the code set, both times it was right on the line of being full and still a good color.
Cold starts, I really don't hear much of a rattle like an obviously loose chain would make. Car does act up when the code sets, struggles to accelerate primarily, but when it's gone the car is totally okay? Haven't seen bad mileage from the car, as one of the symptoms of a bad chain.
Reading online and doing the bit of research I have, a lot of posters come back with saying the timing chain being replaced fixed the issue. So I ordered a kit, and started to disassemble the engine.
What I found when taking it apart, the engine has been taken good care of.
No sludge whatsoever in either head so that's a good sign. The timing chain is factory, and has a bit of play (not sure if this is normal; a coworker who was once a real mechanic said that was pretty normal for this motor)
I did find that the sensors in the head by the cams were pretty grimy however.
Could the dirty cam sensors be the reason why I get an intermittent p0008?
Does the timing chain look to have 'acceptable' play?
I appreciate any answers or insight anyone has to offer on this issue. I want to be fairly certain that replacing the chains is the way to fix it, before I take it all apart.