My brand new c7 stingray with less than 100 miles has what sounds like severe spark knock taking off from a dead stop in 1st gear,is this normal in the break in stages as it hasn't burnt the 1st quarter tank of fuel from delivery & I'm new to this platform coming from a long line of coyote powered vehicles.
I have never experienced this in a brand new vehicle before.

 

The C7 high-pressure fuel pump makes a ticking noise, more noticeable on some cars than others. Could this be the noise?

 

They definitely tick louder than the LS engines because of the high pressure fuel system. They are also very knock limited engines in terms of torque production in that they are tuned to sit right on the knock threshold.

 

Direct Injection also makes noises that can sound like spark knock.

 

As others have stated you're hearing the high pressure fuel system. It's not knock.

Drive the car and enjoy it.

 

Listen to the car idling with the hood open and you will be able to easily hear the noise from the cam driven high pressure fuel pump to compare whether this is the noise you are hearing. The noise is somewhat localized to where the camshaft driven pump is located (drivers side towards rear of engine) but the sound propagates via the common fuel rails so it doesn't come purely from a single point.

I suppose if the dealer put 87 octane in the car maybe it could have a slight knock although the engine should be lightly loaded in first unless you are accelerating hard.

My Z06 only sees 93 octane and I have never noticed any knock but my 2014 Cadillac ATS (3.6 DI) has the transmission shift point programmed so much towards the economy side that under lower speed/moderate torque conditions a slight knock was evident and I moved up to 89 with it. As another poster noted powertrains are programmed for maximum economy and that leaves them running right on the ragged edge of knock under many driving conditions.

If this is your first car with a direct injected gasoline engine you may also notice slightly longer cranking times and this is normal and covered in the manual. The ECM won't allow the injectors to fire until commanded fuel rail pressure is achieved and this will take several engine revolutions during cranking to achieve. Delay will be longer in cold weather (or with a weaker battery) because it will take longer to achieve the required number of engine revolutions.

 

Thx for your help & insight with these direct injection motors as it is indeed my 1st & I am a bit of a worry wort.
I have only noticed it upon a light load either gently taking off in 1st or reverse.
I also noticed that if I apply more of a load that it isn't near as noticeable.
I appreciated your help.

 

Thx for the confirmation,just got back from a very nice romp in the back roads of tn & I notice just how much I miss my old ttop cars I've had in yrs past,but only this monster eats these curves up much better.😎
I love this car,just was worried about the noise that I have always associated with spark knock in the past,seems this is a whole different animal.

 

it's my 1st ever direct injected engine & I appreciate you helping me calm my nerves.😁

 

I was hoping it was something vehicle specific & I am glad I joined this forum as you people are great & a wealth of information.
I hope to someday be able to help others on here as you have helped me,thank you.

 

This is my 1st lt1 & direct injection engine & I'm getting to know it's quirks & I really appreciate your reply & help towards calming my nerves as I really love this car & was hoping nothing was wrong with it,but that noise sure sounds alot like spark knock & it can be relatively loud at times.thank you

 

you wouldn't hear spark knock because there wouldn't be spark knock. Knock sensors would retard timing (and probably throw a code).

 

Well that's good to know,I nolonger worry about,thx alot.

 

I assume you made your run with the top on?

 

Oh the top was definitely off 😎