Bakes

I have a 12 Cayenne V6 6Spd. 22kmi. Recently, I noticed a sound on startup that occurs while the engine is idling fast (over 1kRPM for the first 45sec or so). It sounds like it could be a couple things. It is a ticking/rattling/knocking sound. It does form a consistent cadence that speeds up/slows down with engine speed. Maybe just a noisy valve train? Sounds like it could just be the valves or or cam lobes and rollers making noise, although, they never did before. As the engine's idle slows below 1kRPM, the sound diminishes until disappearing completely, but if it tap the gas to bring the idle back up, the sound accompanies the increasing engine speed. If the engine is already warm, it does not make the sound.

I also wondered if it could be that my exhaust is just wearing-in, because I can also hear a similar noise under moderate acceleration. Sounds kind of like a V8 engine, if you know what I mean? That throaty sound accompanied by a knock, and it is more the knock that I am referring to. I do use 93 octane, so I don't think it is premature combustion from low octane fuel.

I've started the car and gotten out of it to see if I can hear where the sound is coming from, and it sounds to be coming from the engine compartment, and not so much the exhaust. While driving with the windows down, it does sound like it is the exhaust, but that might be due to the forward motion. Or maybe i'm hearing 2 different sounds.

The other thing that I can liken it to is a sound that my previous car, 08 audi A4 2.0T made when it was idling. In the case of that car, I think it was the diverter valve releasing the pressure from the turbo at idling speed.

Anyone else experience this sound or know what it is/what it could be? I'm just worried it could be something bad, like a scored cylinder or bent valve stem or some type of excessive wear on moving parts. I don't want to have my warranty expire and then find out that I have to replace the engine or something crazy. I have a feeling that if I took it to the stealership, they'd say that they can't hear the sound that I'm referring to, because they don't want to fix it because it would be expensive or time consuming.

and please, if you dont know what you are talking about, refrain from speculating and trying to scare me by saying it is something sinister and that I'll need a new engine.

Thanks in advance.

westy66

If you live in a northern climate it could be cold startup noises. Youre probably right about valvetrain, a little noisy until the lifters get to full pressure. Personally I think the v6 and hybrid v6 seem unrefined and loud all the time.

Bakes

Thanks for the response. The only thing is that it didn't seem to make that sound at all last winter, that I noticed. Also, that thing that I mentioned about the noise under moderate acceleration occurs after it is warmed up.

kosmo

I agree the audi v6 is noisy .

Also have you tried a 0 w oil?