loud hum

[SHOtimer]

I have a 95 ATX that has many problems I am gradually getting a handle on. Anyways, when it is cold it idels quiet and sounds good. When it warms up it has a loud hum from the engine bay. It is not the fuel pump I know that noise and can also hear it. I seems to be coming from around the throttle body or where the air filter is. It dissapears the moment I touch the gas and then when the idle drops it comes back. Also when I'm coasting and take my foot of I can hear it also put once I puch the gas one bit it goes away. My thoughts have been maybe the Idle Air Valve makin noise? first SHO don't know much any advise would be wonderful it is very annoying thanx

 

[snowwind1990]

Use stethoscope to detect exact source of hummmmm.
However, I think it is your fuel pump...fill the gas tank and see if the sound goes away..I mean fillitupppp.
Ma Ma M eek!

 

[tomw]

Check your IAB

Tom W

 

[projectSHO89]

Here's a simple test, unplug the IAB connector while you can hear the sound. The engine will die quickly, but you may have enough time to see if the noise disappeared at the time you unplugged the electrical connector.

Steve
89

 

[sdpatt]

I have heard more than a few ATX SHOs make the sound you are describing. Some have modified intakes, some do not. Is yours? It is not a functional problem, but I believe it is a sonic resonance between the flat, closed throttle plate and the filter box. It is more noticeable when a cone filter is used with the flat end piece on it. It's just annoying.

 

[SHOfun 93]

Umm Scotty would be talking about mine, I believe...my shoshop cold air incuction gets a hum sometimes and I have NO IDEA why. Happenes when the temp is right I think...more so in hot weather than cold..

 

[SHOtimer]

I always fill my tank up all the way so I know it isn't my fuel pump. I know that sound very well, it is also annoying. All that I have done to modifly this thing is a K&N air filter in the stock air box. So it sounds like from what you guys are saying is that this is something that I will have to get used to? thanx for the help

 

[naval-avi8or]

If your talkin bout that real high pitched whine, I've got it as well. Can't figure it out. Let me know if you do and I'll do like wise.

 

[BIGSHOMIKE]

My 95 ATX does the same thing, started when I took the silencer cone out, guess that's why it was there? I got in there while it was doing it and sounds like it was coming from the MAF on mine, or around there anyway.