Ticking

[PeterG]

I just picked up a new 2007 coupe MN6 and have driven 43 miles so far.

This quiet ticking sound comes from the engine compartment, is regular, and increases with increasing RPM. It's not a clicking nor a hard clunking. It is a quieter ticking that is most loud from about 1000 to 2300 RPM. I can hear it especially well in second gear at about 20 through 30 MPH.

It seems to diminish over about 40 MPH in third gear.

It's not really loud and most "normal" people probably wouldn't even hear it at all. :L

Is this one of those "Oh ya, that's normal. It's the __________". Could it be the AIR pump or something like that? Does an LS2 even have an AIR pump? Never mind... I withdraw that question. But I am curious about this ticking.

Thanks.

 

[jhecox]

I just picked up my '07 couple MN6 today. I have 36 miles on it and I do not hear any ticking, but that could be because my smile is sooo big that the corners of my mouth are covering my ears.

I will try listening closer the next time I drive it.

 

[BlackZ51Vett]

Could be a number of reasons but I would say it's prob the fuel injectors and nothing to worry about.

 

[PeterG]

A fuel injector sounds like a possible cause. The ticking occurs at about that sort of rate.

Thanks.

 

[PeterG]

It sounds like it is only one injector since it occurs at what sound like only 1 tick per cylinder firing cycle.

Should that injector one be replaced? And could it be something such as a crank or cam shaft position sensor or something else?

Thanks.

 

[BlackZ51Vett]

If your worried about it take it in. It's covered under warranty. If it doesnt bother you that much, wait until you have a few things to be corrected and then have them look at it. I was also very sensitive to the slighest sound when I first picked mine up. hnoes

 

[NORTY]

The intake valves make a lot of racket too. Some of the sound travels back through the air cleaner.

 

[PeterG]

Thanks for all the comments so far.

To me the differentiating characteristic of this "ticking" is that it sounds like it is one (of the set of all) lifter(s), or one (of the set of all) valve(s), or one of a set of something.

I can imagine -- admittedly in my ignorance -- that a part is turning perhaps on the crank shaft and once per firing cycle it gets to a point where it makes contact with something. That contact is what I hear and call a ticking.

It may be "GM normal" since I heard it in another new C6 with 3 miles on it.

But I continue to wonder what is hitting what.

 

[WNH]

It may be "GM normal" since I heard it in another new C6 with 3 miles on it.

But I continue to wonder what is hitting what.

Just my .02

The clicking is probably the normal noise that injectors make.

If something where actually hitting, abnormally, it would not be 'quiet ticking' but more like a clanging sound.

 

[PeterG]

Just my .02

The clicking is probably the normal noise that injectors make.

If something where actually hitting, abnormally, it would not be 'quiet ticking' but more like a clanging sound.

~~~~~~~~~~~~~~~~~~

Thanks WNH. The ticking does not seem to occur anymore than one time per firing cycle. At least that is the apparent regular pattern.

If injectors, it would be only one injector... I believe. And then each of these two cars has one injector that is bad... or one that is making a sound that transmits through to the passenger compartment.

It sounds like -- I envision -- something such as a crankshaft sensor causing a tick upon each revolution.

I hate not knowing enough about stuff I try to talk about.

 

[cntrhub]

Take a long screwdriver, place the tip against the valve cover, your thumb over the handle, bend down to place your ear over your thumb, listen to the noise... Is that the tick?
Place the screwdriver tip along the fuel rail, where you can see 4 injectors (with wires) stuck in the rail... Is that the tick you hear?

No crank, cam sensor makes a tick noise when it swipes across a magnet and coil windings using a .004-.010" air gap. A spark plug would make a crack of noise, not a sensor, nor an intake valve opening. The air pitch (decibel noise on the intake stroke) around the intake bell is any type of intake noise you hear...