I seem to have developed a "ringing" sound which appears to be coming from under the hood. It is VERY noticable when the engine is cold and driving int he 1500-2000 RPM range. I thought it was my WMS velocity tube, so i took it off and put on the stock intake, but the noise is still there. It's also more noticiable when driving, but i can still barely hear it when i am in park and increase the RPM's. Even when crusing at 65mph, i can hear a steady faint ringing noise with the windows up and radio off. Accessories don't seem to make a different on or off, noise is still present. As it gets up to operating temp, it becomes fainter, but still present. Noise disappears at idle, and i also can't hear it a high RPM's (4K)but that might be just because of too much engine noise.
Anyone wanna take a stab at diagnosing this? If i don't figure this out, i'll begin to think the ringing's all in my head!

Thanks!

 

I have something similar... I think with mine, and possibly it might be the same for your problem; the cat converter heat shield...
*shrug*

 

craw underneath tap on converter heat shield and tap it with a screwdriver head or rap on exhaust with a rubber mallet if it is rattleing get a couple of big worm/radiator clamps pur around the shield and tighten down no more problem


worked for me

 

I owned a POS dodge a while ago and had a "ringing" sound. It ended up being the a/c compressor clutch bearings went bad causing the pully to "wobble" and cause a dinging sound.

 

How many miles are on your truck? I'm just guessing, but it sounds like it could be your timing chain, or your starter's bendix is not disengaging fully, causing your starter's pinion gear to rub against the flywheel thus causing the "ringing" noise. Also, could be that your starter is loose. Check your starter bolts. Check your fan bolts too, as a loose fan will make a ringing noise if your bolts are loose enough to cause it to be unbalanced(vibration). Hopefully, it's just a heatshield though. I hope. Just my 2 cents.

 

I have 28K on it. It doesn't sound like a rattling, and i guess you could even call it a whistle, but it doesn't sound like wind whisting through a leaky window in your house during winter. What's confusing to me is why it becomes less noticable after it's warmed up. So something must be expanding and filling the gap, decreasing the noise? Most people that complain about their FIPK whistle say that it gets worse as the vehicle gets to operating temp. While mine is still present at operating temp, it's just more faint.

I have seen people saying for the FIPK fix to remove the plastic return hoses in the intake and replace them with rubber and use hose clamps. I'm guessing that means their "whistling" is coming from the plastic hoses not sealing tight?

I'll check the shields and starter for process of elimination. I'll let you know what i find out. Hopefully i can check those tonight.

Thanks for the input so far, any other ideas are welcome!