Annoying Rattling... what is it!?

[Rob95CS]

I just can't seem to figure this one out. There is this annoying metal-metal rattling sound coming from the front end of my car when in gear at low speeds. It only does it when I tap or hold the gas pedal lightly at speeds about 35 and below. It's completely quiet when just coasting, and it's also quiet if I really get on the gas. When in park, I cannot recreate the sound by revving. ONLY does it in gear. Today, I just happened to catch the rattling in action while stopped in my driveway. So I left it in gear, set the parking brake, and walked around the car. It's heard best from the front wheel wells (either side) and the sound seems to resonate all the way across the vehicle. It sounds as if something is rattling up against the firewall or something. Any idea of what it could possibly be? It's driving me nuts!

[supreme_style21]

This happens to me ALL the time.. here is the cause:

 

General Motors

 

 

 

 

 

 

Just kidding.. My GM's seem to be loaded with squeaks and rattles. I just turn up the radio really loud and ignore the rest. Doesn't sound like anything I've ever heard before.

[PJB]

Check the exhaust and converter heat shields.

My truck was rattling and I found the converter heat shield was just sitting on the converter- the bolt holes rusted out around the bolts and it fell.

[Rob95CS]

Check the exhaust and converter heat shields.

My truck was rattling and I found the converter heat shield was just sitting on the converter- the bolt holes rusted out around the bolts and it fell.

 

Hmm, I am missing two bolts on the converter heat sheild (corners from each other)... but I can't seem to find the right size nut to go on there. The stock ones are plastic looking things with a built-on washer. Anyone know what size these are, and where I could pick them up? Also, why would it only rattle at low steady speeds?

[SmokesGTP]

I have the exact same problem, exactly. It annoys the hell out of me.

[92turboLE]

if it sounds like it is coming from the front under the car, i would be willing to bet money on the catalytic converter. Mine rattle like you wouldnt belive until i get on the gas and it goes away, but at idle, it is insanely loud - which is why i have my Catco Catalytic converter ready to install, but imma wait for my dual exhaust.

 

- Justin

[Rob95CS]

It doesn't rattle at all at idle. Besides, my converter is maybe 3 weeks old? Just had it replaced.

[topless94style]

My car does the same thing at low speeds or rpms anywhere from 1500-2500 rpms. After that it goes away, and the only time it is there at idle is when i first start teh car. It is the cat.

[Rob95CS]

I really don't want to resurface this thread, but I still have not figured out the rattling sound. I definately know it's not the converter, because now I don't have one! I got so frustrated today I crawled under the car and pulled off the heat shield that's up near the downpipe to see if it would go away. It didn't. (Is that the only heat shield, BTW?) I'm stumped.

[mfewtrail]

Check all exhaust hangers while you're inspecting other things under the car, the bolts might be loose on them. I recently had to tighten up the bolts holding the rear exhaust heat shields in on my 93 GP due to rattling at idle and a bit on the highway..my loud ass exhaust rattles pretty much everything in the car to some extent. I need to take those shields off and paint them this weekend as well. :oops:

[maybe2fast]

sounds like a mount to me!!! the right side lower motor mount the metal on metal is the mount that is broken. Mine did the same thing.

[WhiteOut]

It doesn't rattle at all at idle. Besides, my converter is maybe 3 weeks old? Just had it replaced.

 

I had the same problem after I had my exhuast work done. They forgot to tighten down a bolt on one of the exhaust flanges and it was causing a rattling noise.

[Rob95CS]

sounds like a mount to me!!! the right side lower motor mount the metal on metal is the mount that is broken. Mine did the same thing.

 

I sure hope not! But I think that would cause some other issues like jumpiness and engine roll, am I right?

 

Anyway, I'll do some inspecting over the weekend and check every single nut and bolt attached to my exhaust system. I'll post back with my findings.

[Rob95CS]

Ok, finally had some nice weather, so I checked everything I could. All the exhaust flanges are tight and all the exhaust heat shields are tight and not rubbing. The engine mounts SEEM ok. They're a bit rusty on the outside, but the rubber is alright. I guess I'm not 100% sure what they should look like.

 

Maybe2Fast, you say the right side lower mount... would that be the drivers side to the front of the car? Because that's where the noise seems to be coming from...

 

Edit: The mounts are hydraulic, right? So they would leak if they were bad? My drivers side front mount has some fluid around it and all over the place nearby... but it doesn't seem to be coming out of the mount. It's just on everything else nearby including the airdam and some of the lines. It's a yellowish looking fluid. Kinda resembles brand new synthetic engine oil. Have we found a culprit?

[maybe2fast]

sounds like the mount (mine is the 3.1) and the mount was on the pass side. The mounts are hydraulic and the fluid usually gums up, around the area. I bet thats the problem! good luck