good point Ken, I didn't even think of that.....

 

I've noticed this sound in these conditions also. However, I'm of the opinion that it's an "auditory illusion". Specifically, my thoughts are:
1) The F20C is a fairly noisy engine, which makes valvetrain noise even when perfectly healthy.
2) Low-frequency sounds are not processed in a "directional" way by our brains (that's why subwoofers work wherever you place them). So even though the low-frequency sounds are also reflected off the barrier, we only notice the higher-pitched "ticking" as being reflected. In effect, the reflected sound has been filtered.
3) I don't hear the ticking (as much) under other conditions, e.g. revving the motor while stationary.

My conclusion/theory: Driving next to a barrier creates a specific set of conditions in which we notice certain high-frequency engine noises more than we usually would.

 

Maybe you should reset your ECU, just to rule out detonation. If it is detonation, it will change for the better or worse, then go back to normal after a couple days.

 

Well i dono if its the same for the s2k, but my friend has a Eclipse and one day he said he heard the ticking sound from his enging(it was pretty loud i guess) and it ended up that his engin oil tank was dry...

 

I drove without my hood (don't ask why) and let's just say the engine note was a loud ticking sound! Don't worry, it's a combo of the fuel injectors and valvetrain.

 

definitely not detonation... doesn't sound like that at all. i've had the misfortune to hear that quite a few times.

i'd be shocked if the injectors on this motor clicked loud enough to be heard under these conditions. in the past, when trying to diagnose fuel problems, i've had to use an automotive stethoscope to even hear them opening and closing!

the more i listen to it, the more i think it's vehicle speed dependent and not engine speed dependent. in my case, it may be more along the lines of xvipers suggestion that there is some bit of flotsam lodged in or on or near a rotating assembly. still working on figuring it out, or at least determining that it's normal.

i also like the barrier filtration theory... i may have someone else drive the car past me so i can listen to it more directly. revving the car while sitting still seems so noisy that i can't hear any specific sounds.

 

My car doesnt have the ticking sound, but when the car is cold, there is a very small vibrating sound when the RPM is between 4K5- 5K, only that range. It is not loud at all. With the radio on, you cannot hear it. I first noticed it when I didnt have the radio on one time cuz I was talking on the phone. When the car is warm, there is no noice. So weird. Anyone knows what it is? Do I need a valve adjustment? My car has 18,000 miles.

Thanks.

 

[QUOTE]Originally posted by Carlson
[B]My car doesnt have the ticking sound, but when the car is cold, there is a very small vibrating sound when the RPM is between 4K5- 5K, only that range.

 

Cuz if it is coming from the engine (valves), the noise should be there all the time, right? It doesnt bother me now, as I always have the radio on. But I am afriad it's gonna get worse. Also, my top started to sqeek too. I drive with the top up a lot now (not as crazy as before, 50 degrees, top down)

 

Yeah, so weird, only around 4-5K RPM.