Same here. It’s very audible when cold, but when warm you have to really really listen for it and be next to a wall to hear it, but it is still there. I honestly think this is the characteristic of the drivetrainUpdate: I initially stated that the clicking noise goes away once warm. Not true, I heard it with the car fully warmed up as well, though it is muted compared to when cold. I was driving next to a wall and heard the clicking on deceleration.
Can you take a look at my video on my last post. Is this the same piston rattle? And is it normal?More than likely piston rattle. There is even a table in the PCM to account for it. GM LS engines have it real bad when cold. It's a design compromise - if it wasn't loose in the bore, it wouldn't rattle, but then it would be too tight when it warms up and when you're rompin' on it. The dealer isn't going to say "piston rattle" or "piston slap" because it makes it sound like the engine is a POS and scare you. Nevertheless it is normal/expected.
Would you say this is harming the engine? Looks like I need to take the car back to the dealer..I hear what sounds to me like air rushing past the throttle blade after you rev it a bit. It doesn't sound like piston rattle to me though, piston rattle sounds much worse.
If you listen closely to "Take 4" on this video, you can hear it. Almost sounds like rod knock because the piston is deep inside the engine, not like a lifter tap where the lifter is up on top.
You could have a friend rev the enging slightly like you did, while you listen close to the airbox. If you hear the whoosh after a rev, it's probably the increased velocity of air running past the throttle blade as it closes (after you take your foot off the gas).
If you're talking about the boomy/bass-heavy sound during the transients, that's completely normal, that's the PCM playing with the cams, timing, fueling and throttle. You can kind of see it if you bring up the wideband voltage in the dash - you can see it bounce around a little bit after you stab the throttle ever so slightly.
Care to offer any support or backing for this theory/fact? Not saying that I don't believe this, but would like to hear more about how you came to this conclusion or learned this. In the long run, is this detrimental or will it cause an abnormal amount of wear on the guides or the chains? Is this due to lack of proper adjustment of the tensioners, or is this necessary for increased tension at higher RPM and thermal expansion?The clicking sound is 100% the sound of the timing chain tensioners collapsing at low engine speeds and oil temperatures, causing a quick slap of the timing chain on the guide rail.
Sorry for the late reply! Yeah, I've had a lot of experience with the tensioners as of late. My 2019 A10 had the chirping noise at hot idle, 2k rattle, and did not have the lift off rattle, which is the sound in question.Care to offer any support or backing for this theory/fact? Not saying that I don't believe this, but would like to hear more about how you came to this conclusion or learned this. In the long run, is this detrimental or will it cause an abnormal amount of wear on the guides or the chains? Is this due to lack of proper adjustment of the tensioners, or is this necessary for increased tension at higher RPM and thermal expansion?
TIA for any additional insight!