BRCC

I have a Z51 A6, I am just curious as to how much engine noise do you have.

Now I am talking about at idle. In essence just starting it up and letting it idle I hear what appears to be a lot of clatter coming from what appears to be from the engine area.

So my question is does your car put out any noise from the engine area on idle, not exhaust, just valve train or other areas of the engine.

Gr8ful

Yep and if you listen when you start the car you will hear what sounds like running water. I found a GM memo to the techs that's states it's the oil returning to the oil tank. I though I was hearing things.

Zymurgy

The very high pressure fuel pump on DI engines also causes a ticking sound. This is normal.

W88fixer

I think the injectors operate at about 150 Bar or about 2205 psi. Don

Wormwood

This is my second DI engine & it use to bug me to death the noises it makes. Everyday it was a roll of the dice, e.g. You'd go to work in the morning & Monday, it'd sound like a fart machine. Tuesday it would have that stupid ticking noise. Wednesday, it would run like a cat with turpentine on its *** & so on.

After researching the whole direct injection engine idea, I realized manufacturers are doing some wild things with these engines, like stratifying the air/fuel mixture up to 40:1 & as such, it requires more subsystems, ECU management, drive cycle tests. Here's a few things that come to mind:

2 & 3 staged fuel pumps; electrically or mechanically driven
Fuel tank vapor management system
Crank case pressure recirculating system
Direct injectors & the electrical control systems
ECU open & closed loop fuel/timing maps for direct injection engines
Accelerated warm-up of The O2 sensors from a cold start

What it turned out to be on my last car was the ECU drive cycle tests. There's a battery of tests that are ongoing to measure different components & make sure they're still functioning. The ECU's for DI engines will periodically test each individual direct injector to make sure it's putting out the proper amount of fuel, called something like cylinder contribution test. Anyway this was specifically what made that occasional ticking noise that was so loud that it could be heard in/out of the car & over the exhaust note.

You might want to invest in an OBD-II scanner. It can help to understand what the ECU is doing at any point in time & why. Additionally, once the 2014 corvette service CDs/manuals are out, you'll know how to initiate or postpone these periodic tests so they won't be starting at inappropriate
times.


Hope this helps.

Wormwood

C7Joy

Wow! That's quite a squirt!!

adamsocb

Try turning the AC Compressor off. My C7 makes a subtle, but definite noise at idle.
If I push the Climate Control "AC" button on the dash it stops, then if I push the "AUTO" button it returns.

When I am at Spring Mountain in February I hope to compare mine to several other C7s to see if it is normal. If not I will have the AC Compressor checked.

BTW, my 2008 C6 AC Compressor is silent.

BRCC

Thanks for all the answers, all good responses. As far as AC I am not running on AUTO, have not used that mode since verifying it worked when I got the car, however, all information above is good to know. Bottom line the noise is normal and only at idle.

ahesq

Did you find that other's A/C compressors were noisy?

Cruiter

Of course I'm an EXPERT!
X is an unknown quantity,
Squirt is a drip under pressure


Sorry, Couldn't help myself. One of my email taglines .

BigJoe

I have two different noises. One is a ticking sound from the engine that is constant but varies with rpms. I attribute that to DI. The other is the HVAC fan sounds like it is hitting something, a fast tic, tic, tic sound that is very soft and only noticeable at very low fan speed. This varies with the speed of the fan up to about the 3rd line when the rushing air drowns it out. Both of these are drowned out by even moderate road noises. Not going to open Pandora's box by asking the dealer to look at it... I have visions of the dash being torn part as they look for the fan noise.