"Ticking" noise under the hood...

[sensfanrk]

Hello! I went under the hood tonight before work to pull out my block heater cord for the first time... I've never had my car running while the hood was open, so I have never listened to the engine outside the car... I heard a loud ticking sound, so I figured that it was just a rattle in the engine compartment, so I revved up the engine thinking that it was just the idle speed making something vibrate. I still heard the sound! I was just wondering if anybody else hears this from their engine at idle? Please let me know if you do hear it because I don't want to take it into the dealership and find out that it's supposed to sound like that... Thanks!

[ragingfish]

Check the vacuum switching valve, which is attached to the airbox.That ticks about once or twice a second as it switches...I really only hear it loudly in cold weather...

[redlava]

Could possibly be a lifter going bad. I doubt it on such a new vehicle, but you never know. My old Chevy Malibu had a noisy lifter and it did exactly that.

[JohnC]

Does it change with engine RPM?Does it do it when engine cold/hot /both.A/C or defrost on?More info needed.

[ColonelPanic]

For your sake, I hope it isn't the same ticking I have. Still haven't been able to get anywhere with my issue. Mine is definitely temperature related, very pronounced when the engine is cold and the temps drop below 40 F.I've never found the 1ZZ to be particularly quiet at idle anyway, especially from the outside. The ticking could be normal - VSV valve in the airbox, fuel injectors, timing chain, etc... So it may not be anything to worry about. When in doubt, take it in, sure wouldn't hurt to have them check it out! Hoping for the best for ya! Let us know what's going on!

[joatmon]

Quote, originally posted by redlava »Could possibly be a lifter going bad. I doubt it on such a new vehicle, but you never know. My old Chevy Malibu had a noisy lifter and it did exactly that. Do these engines even have lifters in them?

[Psychobroker]

Sounds like the VSV valve "doing its thing" to me.

[ColonelPanic]

Yes they do...

[sensfanrk]

More info... I had just arrived at work, which is approx. 40kms/30 minutes of highway driving from my house. The car was sitting at idle (auto. trans. in park) The noise seemed to be coming from near the airbox, or close to it. I'm just going to leave it for now and assume that it's normal, but if I start hearing it from inside the car, I'll know something isn't right! Thanks for all your input! If something changes, or if I hear something, I'll be sure to pass it on...