87 carerra intake/throttle body noise

[jlewis5534]

I just started noticing excessive growling/bearing type noise that seems to come directly from intake/throttle body area. I hear noise when engine is at idle or when engine is on the way down to idle when coasting to a stop. With engine lid open, I can hear noise coming directly from intake/mass airflow sensor and is noticable from 800 to 1100 rpm. Have not experienced any power loss; engine still pulls hard in every gear. We are leaving on 5 state road trip soon; any input would be greatly appreciated. Have already checked engine air filter housing, it is snapped down tightly.

[steely]

Feel the ICV and or listen to it with a screwdriver. I never heard of it making a lot of noise, but it is essentially a small servo motor. Maybe it is acting up. Might need cleaning or is on the way out. You could try disconnecting it after the engine warmed up as a test.

[Hodgey]

jlewis:
have you tried the ambient air valve (AAV)? it sits forward of the oil filler neck, almost behind the deck hinge. It looks like a dome...simple to change...ask me how I know

I had the same noise as you. No big deal, just annoying I know.

[aerodyn930]

Follow the previous tips , If still unsure , Remove the fan/alt. belt then start the car, Rule out alt bearings,

Good luck, Lou

[jlewis5534]

I used a long screw driver to locate noise, it sounds like it comes directly from or directly behind mass airflow sensor. It sounds like noisey valves but I just had them adjusted 2000 miles ago. It's kind of a rickety-clattering noise. Engine runs strong though, no performance issues at all.

[jlewis5534]

Where is this valve located?

[jlewis5534]

I will disconnect belt and see if noise goes away, but noise seems to come from up higher right from or behind mass airflow sensor

[jlewis5534]

Thank you for the tip, removed the belt from alternator/fan and noise went away, getting alternator replaced today.