Noise from engine compartment Options

[mkernz22]

Alright, so this noise started to occur in the engine bay a few months back and I've been starting to get annoyed with it. It's not a constant rotating noise, but it only happens at about 1,600 RPM's. It is definitely a rattle of some sort, but I can't tell where it is exactly coming from. I have only 2 thoughts on what it could be, either the exhaust rattling on the cross member / sub frame or the front / rear engine mounts are bad. From what I know, it might still have the original mounts still in there because they looked kind of old when I had the engine out. Also, I did put the poly inserts on them, which is why I think it would most likely be the engine mounts. I have a video so you guys can hear it, don't mind the sound from the intake.

[95CelicaST]

Likely due to the poly mounts causing excess vibrations to enter the chassis and rattle around. Welcome to poly mounts.

[mkernz22]

I've had them on for a year now and that noise started about 3 months ago.

[krom8]

Is your intake secure? Do you still have a catalytic converter, if so the shield might be coming loose on it.

I've had them on for a year now and that noise started about 3 months ago.

The problem with those types of mounts is that since they stop most vibration at the mount the vibration will transfer to other areas which can loosen something else. The more I listen to the video it sounds like a loose piece of aluminum.

This post has been edited by krom8: Jul 11, 2012 - 4:21 PM

[trdproven]

if it makes the sound while in idle, im pretty sure you can pinpoint it by putting your ear next to the sound. battery tray, manifold shield, subframe loose, polymount loose, intake rattling, Im not sure.

the vid wont load up at work for me to see.

This post has been edited by trdproven: Jul 11, 2012 - 5:30 PM

[mkernz22]

It only does it at 1600 rpm's, nothing higher, nothing lower. I don't have a cat on the car, and it's definitely not the intake, or do you mean the manifold itself?
The only two reasonable answers I can think of is that the exhaust is hitting somewhere on the car (being that the flex section was F-ed up when I got it and had to get it chopped and extended in some places to fit properly) or the engine mounts. I'm going to jack the car up tomorrow and just take a look at the exhaust

[mkernz22]

Well I finally figured out what what causing the rattle. The bracket for the counter weight, on the front engine mount was cracked so it was being held on by a small amount of metal. So the vibration from the engine would cause it move and it would hit the cross member and create the rattling noise. It's very nice not having that sound anymore lol