Ticking under the hood

[Bloo Ice]

So I'm at the pump filling up mom's car tonight and hear a ticking. I've heard it before, but I finally decided to investigate. It sounds like a relay clicking, but very very fast, like 2 or 3 clicks per second. I revved it a little bit, and it remained there. I revved it a lot, and it went away probably around 2500rpm. Sometimes when it went back to idling it wasnt there until I would just barely touch the throttle...sometimes it came back on it's own.
I pinpointed it to a little plug by the air box. It's a gold unit with a blue plug hooked into it. I could feel the ticking. Anyone know what this is, and why it's soo annoying?

[trix0349]

i have a 03 matrix and it does the same exact thing. its located under a black box for me under the hood. id like a answer also

[SpinnerCee]

You didn't say what year and engine, so it's hard to know what you "see" and hear-- injectors make noise that coincides with RPM, some engines also have a cold start injector that will only operate during warm up -- injectors have electrical and fuel inputs, so they should be easy to ID.

Generally, relays should not be "ticking" very rapidly -- sure it's not the turn signal/hazard flasher? They make noise on purpose, but they're usually in the interior, but they may also operate a relay under the hood.

Lastly -- some engines have a MAF [Mass AirFlow] sensor (in the intake tract) that heats a fine wire using battery current, resistance is measured across this wire to determine airflow -- there may be a relay here that is intentionally intermittent so that the wire does not burn, and so that resistance can be read on intervals(?).

[trix0349]

thats true but i hear mine around where my intake is. so whatever is around it, its making a ticking noise but thats only when the car is warmed up and the oil temp is warm.

[AE92SR5]

Have you recently checked the amount of oil you have in your vehicle. Believe it or not I had a costumer in last week and they had some type of clicking noise. I test drove it and noticed when your going faster you don't really hear it. I pulled it in and checked the oil he had about a 1.5qt. So I did a routine oil change and bam the clicking is gone. So try that, that may or may not be your problem but its worth a try.

[trix0349]

i had a oil change about a month and a half ago and i have bout 80k on my car so i use the synthetic oil .. i dont change it untill every 6k

[black wall st]

They have adjustable lifters, and if they wear enough they will tick until you get them adjusted. 2000 Corolla, same problem, also had an exhaust manifold gasket leak.

[imilla52]

add more oil if it clicks still u may have shot a rod through ur engine