Buzzing Noise in background of radio

EDieter · Post by **EDieter** » Wed May 30, 2012 7:16 am

First, I don't know if this is the correct part of the forum to post but seeing as it could be engine related I decided to post here.

2002 Dodge Neon SXT 63xxx miles ATX
(has turbo kit but bother problems have been around since before I installed the turbo kit)

I have a buzzing noise in the background of my radio. If i turn my radio all the way down I can hear the buzzing noise by itself, and if I turn off the radio obviously the noise goes away. The odd thing is the noise gets louder as my rpms increase, and decreases with the rpms as well. Me and my girlfriends dad were trying to listen around in the engine to see if anything as making a funny noise and we noticed that the Idle Air Control Valve was making a noise (not sure if it was out of the ordinary or anything), so I disconnected the IAC and the noise went away both inside the engine and in my radio.

Is it possible that my IAC is causing this "buzz" in my radio or is it probably something else. I'd hate to order a new IAC and then find out that it doesn't fix my problem.

I have one other question and my search has been, well, useless because I don't really know how to describe whats happening. So here is my best try, there are instances when I am driving, mostly within the first 5 minutes of starting my car OR when I am on the highway between 65-75 MPH (I have not made a correlation to speed yet, it just seems to happen in this range MOST of the time) that my a/f ratio will become very rich(?) (my afx powerdex is reading <9.0) and cause my car to sputter. I literally have to take my foot off the gas pedal and coast until it decides its no longer mad at me. If I continue to accelerate at a normal rate or even try to increase (unless WOT) it just sputters and the car shakes. Any in put on this would be helpful as well

sidepipe87 · Post by **sidepipe87** » Wed May 30, 2012 7:47 am

The only advice i can give is to look at the back left side of the cylinder head. There should be a small black plastic square bolted to the head with a wire going to it. It is some sort of noice cancellation device to eliminate engine "noise" in the radio

Post by **occasional demons** » Wed May 30, 2012 8:19 am

Check the grond at the back of the radio also. If it is only grounding through the antenna, it could cause issues. Check all your other ground points too.

The .47 capacitor on the head can also short to ground, but your car will not run at all. It absorbs the electrical noise from the coils, and injectors.

If it is partially shorting, IDK if it would cause the fuel issues. Prolly not likely, more like a lean fuel than rich, since the voltage to the injectors would be dropping, but then also the coil would have less primary voltage. So it is a toss up. You could just unplug the wire, and see if the engine issues clear up.

Dranz · Post by **Dranz** » Wed May 30, 2012 2:06 pm

I think you should change the title and switch the order in which you asked the questions... Do you have an aftermarket stereo system? A subwoofer? If so, how are your RCA lines run? They should run on the opposite side of the power cables. If they must intersect at some point, they must cross at a 90* angle as to not cause interference. If not, replace the radio frequency interference module that occasional demons mentioned. The ignition coil is generally the main culprit... But a noise filter could be added to or used as a replacement to the rfi module.

As far as your fuel issue, what are you using to tune the vehicle for boost? Rrfpr? Bigger injectors?

Danteneon · Post by **Danteneon** » Wed May 30, 2012 2:10 pm

My guess is that you are running some kind of aftermarket audio. If so, ground the outer part of your RCA connectors and you should be fine.

EDieter · Post by **EDieter** » Wed May 30, 2012 10:51 pm

I do have an aftermarket sound system, I will check the stuff mentioned.

As far as fuel, i use a rrfpr, and have bigger injectors for my turbo application BUT this was happening BEFORE I installed my turbo application. My a/f monitor gave me the latest blue because I noticed when it happens my a/f drop to less than or equal to 9.0.

Dranz · Post by **Dranz** » Thu May 31, 2012 9:49 am

So you were having fuel issues... And then you turbo'd it...

Do have access to any scan tools that can sensor values? If you do, plug it in and make the issue happen. Check sensor values, until you find the sensor that seems to be out of the ordinary. That will be your issue. Of course you shouldn't do this while you are driving, so maybe show a friend how to make the issue occur, or have your friend check and write down the sensor values. Some scan tools can also run a playback system.

EDieter · Post by **EDieter** » Thu May 31, 2012 11:12 am

I didn't know what the issue was when it first happened. I had a mechanic look at it, and he said my spark plug wires were just bad, so he replaced them and it seemed to fix it. I say seemed because I didn't notice the problem for awhile (maybe I just didnt drive it at those speeds I mentioned). This only happens on the highway when going over those speeds. I'm taking it to a new mechanic once I move in july, maybe he can give me a better idea of what's going wrong.