New IAC CAUSED howling noise

[goalkeeper21986]

I've seen a bunch of posts regarding old IAC's causing a howling noise, and cleaning/replacing made them better; however, I just installed a new IAC and now I have howling at idle when I didn't have it before.

I bought the cheapest one, duh, http://www.rockauto.com/catalog/moreinfo.php?pk=2414180&cc=1354553
at RockAuto. Has anyone else had this problem.

FYI I noticed that my replacement came with a gasket shown in the second picture in the link. My old one did not have a gasket on it. I installed it thinking that it should have been there in the first place. Could this be the cause? is this new IAC bad?

Confused.

Thanks!

 

[gonenuke]

Did the gasket look like this one? This is the one that your 99 SOHC should use.

 

[goalkeeper21986]

Negative, but I've got the OHV and the gasket looked like this

 

[goalkeeper21986]

Interesting, I just looked at Rock Auto for an IAC gasket and it showed this for the '99 V6 OHV:

 

[goalkeeper21986]

Howling went away on its own. I guess something broke in.

 

[Turdle]

Some air filters will cause this also. Ours howled, but went away with a new air filter. Seems to be a reed type action going on in there somewhere-I think it is the rubber seal inside the iac which actually vibrates.

 

[goalkeeper21986]

That sounds pretty likely. I'm pretty sure I messed around in the airbox after noise and never made the connection that that was the fix.

 

[sirsimalot]

new IAC

I have a 2000 Ford Explorer. It started howling on me as well. When it first started doing it I could unplug the MAS and it would stop. After a while that did not work anymore. I replaced the IAC from a new one that I bought on ebay and that made it worse. I put the old one back on it and that put it back to where it was befor. If I unplug the IAC while it is running the noise goes away and the idle drops considerably. I can rev the engine up in this state and still get no noise. I will try another IAC when I get one to see if maybe I bought a faulty IAC. Also the gasket you mentioned I tried with and without the gasket and it seemed to make no difference.

 

[Mounty99]

Has anyone else had this problem.

Yes.

Could this [the IAC] be the cause? is this new IAC bad?

Yes. Just unplug the connector from the IAC. If the howl goes away, then replace the IAC.