Valve Noise?
 

Its been a while since I posted, no issues and everything running great. Went to leave tonight and heard what sounds like valve noise? But its only when I give it gas, over 2900 RPM, and also does it when in park if I rev it above 2900RPM.

it IS cold, about 7 degrees outside, but this is my 3rd winter with it, and its never done it before, and its definitely been colder.

Just some background, 2009 Touring... 97,070 miles.. Royal Purple 5w-30 @6,000 miles on that oil so far, coil packs and spark plugs replaced around 70,000 miles, and I replaced all the idler pulleys, belt tensioner, and belt about 10,000 miles ago. I've always used synthetic. The car doesn't lose power when it makes the noise either...

https://www.youtube.com/watch?v=P7cRKcdtYCs

I'll try and take better audio tomorrow.... but at least gives you an idea..

I won't be any help, sorry. But you're right, that sounds horrible. I have only owned mine a few months and hope it never sounds like that. Good luck. I'll check back in as I am curious, too.

Do you have an aftermarket exhaust? Check for exhaust leaks?

I have an x-pipe and resonated mid pipe from garageline and the axleback is Top Speed, but no leaks...

oddly enough, remote started it this morning, drove to work, tried it in park and while driving, no noise.... wtf.

missfire ?

I'm just guessing ......but it sounds like it's starving for oil ....maybe low oil or low oil pressure ....and being very cold maybe oil is not reaching the lifters ....how long did you let the car warm up for ....and how long had the car sat before driving when you heard the noise ....maybe the next morning you didn't hear anything if the oil heated up and coated all parts .....like I said just guessing from a few things I have seen/heard before hope it isn't anything serious.

It warmed up for about 15 minutes. The last time it had been driven before I heard the noise was 5 hours before. Oil level is perfect... I'm going to change oil this weekend as a precaution regardless

just an update.... I changed the oil, it wasn't low, no burnt smell, no sludge... however twice right after startup, this odd whirring sound could be heard from the top rear passenger side of the engine, almost what a pulley with bad bearings sounds like... it hasn't done it since those 2 times.. Just weird.

everything else is fine, it runs good, good gas mileage, acceleration is great... not a clue.

I would get an oil pressure gauge and monitor your oil pressure.
Low oil pressure (but not low enough for the oil pressure light to come on) will increase engine noise and reduce how well the VTC/VVEL system works.

Sounds like timing chain slap due to a sticky tensioner or broken timing chain guide. The VTC's can also make a similar noise. 6,000 miles is farther than I would go for mileage even on synthetic. I change at 5,000 miles period. If it keeps it up, you are going to need to go into the engine to find the issue or it won't be good. What kind of oil filter do you use? Our oil filters are too small to run a long time.

its probably your vvel, try running 10w30 or a double ester base oil

motul 300v or amsoil dominator

If nobody comes up with a solution, I'd try running ester oil for a while. It's supposed to lessen VVEL noise.

I would check all of the front of engine rotating parts since they receive most of the water salt etc. through the grill. So you are looking for play in the alternator, a/c compressor pulley idler and tensioner. NExt use a piece of hose or stethoscope to isolate location of noise. Properly maintained engines such as yours shouldn't develop lifter noise unless they are over revved.

I replaced all of the pulleys, belt tensioner, and new belt a few thousand miles ago.

I did what you said and rechecked everything on the front of the engine and everything is tight, no bearing noises or belt slipping etc. And the noise is definitely coming from the top of the engine near the firewall, its hard to nail down exactly as it doesn't always make the noise.

I'm going to try the ester oil next oil change. Its odd, to me it just sounds like overall the timing is off. Even on slow acceleration it sounds like its off a bit. If the guide is broken or sticky, could it have caused it to jump a tooth? is there an easy way to check this? I remember the 350z had covers on the front of the engine you could remove, but I know the 370 doesn't have those...

If something major (like jumping a tooth) has happened, a DTC should have been thrown. If you haven't scanned for codes, that would be a good place to look.

Yep.. scanned with a snap-on verus, no CEL and no stored codes...

Its getting the roof fixed right now (car wash entrance door went into neutral and came down on it, luckily doesn't need replaced, just dents removed and repainted, $1,292, and car wash covered it all...)