I recently fixed my P0024 code by replacing the EVT sensor. After doing the relearn procedure a couple of times manually, holding the rpm's between 1.8-2k, the car seemed to run normally. About a week later I heard a slight rattle in the engine, so I took it into a local import shop to scope it and see if they could tell me anything; they informed me it was probably just the camshaft sprocket rattle and showed me this service bulletin. So my question is what exactly is going bad with the sprocket, tooth wear, chipped tooth, and can this cause a catastrophic issue with the timing? Also after looking into what it takes to get down to the sprocket has anyone found a way to quite this type of noise, sea foam(?), without replacing the whole assembly?

 

All that TSB states is that the service department should not automatically replace the actuator solenoid without doing the COMPLETE troubleshooting.

Usually what happens is service techs start cutting steps in the FSM because they think the problem is something else. They replace parts under warranty, the dealership bills it back to Nissan, the bean counters get a mountain of bills for solenoid actuators, the customer comes back because it's still exhibiting the same issue, the bosses realize that it's a widespread issue of technicians replacing actuators which are NOT broken, the head of Nissan service sends out a TSB to tell them to stop.

That's basically what this TSB is, telling the techs to stop assuming the actuator is the problem until they have used ALL the troubleshooting steps laid out in the FSM.

https://infinitig37.com/TSB/ITB06-023a.pdf

As for your cam rattle, sometimes they do break but it's uncommon, a user here on the forums did come across a broken cam actuator last year though. I would definitely get a second opinion because it's far more likely that the sound is coming from somewhere else. How many miles are on the engine?

There's a LOT that can cause a rattling sound on the G35, the chain tensioner should be replaced about every 100k, sometimes the end of the chain guide breaks and it gets extra slack, sometimes you end up with the pieces in the lower oil pan. Not using the correct viscosity of oil can DEFINITELY cause noise like that.

First I would change oil, if you're using synthetic go back to conventional dinosaur oil of the correct viscosity for one oil change cycle to see if the problem goes away. If you're already using dino juice then just get an oil change anyways, this whole systems works off oil PRESSURE and synthetic oil drops oil pressure due to the nature of a smaller molecule on these systems designed for conventional.

Don't use any additives, especially things like engine restorer, they are notorious for causing widespread issues on the VQ because it screws up oil pressure drastically.

 

The engine has 132K on it, and I use full synthetic. I had never come across anything saying otherwise, thanks for the tip! I'll try an oil change and see what it does.

As far as the chain guide I hope not because these engines look horrible to tear down (although I did come from a car with a timing belt so that was pretty easy to deal with).