The car is a 2002 LX Sedan, 1.7L SOHC, about 130k miles on it. The noise is most noticeable at idle, but it continues up to about 2000 RPM. It sounds like rocks rattling around in a plastic box, it seems to be coming from somewhere on the driver side of the engine around the belt area. The car other wise runs just fine.

is there any sort of engine check light? run a code scanner and see what comes up. If theres no codes then youll have to find it yourself. led flashlight and keen eyes works best lol

No, engine light and no codes on the scanner. I've looked hard and long and can't notice anything. Checked all the pulleys for wobble by hand and the all seem tight.

do you have an aftermarket exhaust?

No, 100% stock everything.

is the heat shield over the exhaust manifold loose and rattling around ???

It's not. And this sounds completely different that a typical exhaust rattle.

Maybe you got bad bearings in one of your pulleys.

Made a short video [autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=1191& transactionid=1329516254-688415990&posted_by=G3rain1_www.civicforums.com&yo utube_video_id=quBY-mKto_M[/autostream]

its not your hood latch? does it sound rotational?

just watched the video. it does seem like it could be bad bearings like the previous post said. cant really get good audio on my laptop though. dont take it to the dealership. call smaller shops first and see if they can take a look for free.

Finding a reliable and competent shop has been a challenge for me, I've been trying to do all my own work, and learning as I go.

Interesting observation, the black plastic cover on the side of the engine produces a similar "note" when taped on with a wrench.

I wanna hear you blip the throttle to about 2000 and let off a couple of times.

Does the engine have oil in it?

Yes it does. Oil change was the first thing I did when this noise showed up, but it had no effect.

I'll do the throttle blip video tomorrow.

Here's the rev to 2k video as requested. [autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=1194& transactionid=1329588302-688415990&posted_by=G3rain1_www.civicforums.com&yo utube_video_id=Fx42eZ2Rl10[/autostream]

I meant use the throttle/cable in the engine compartment, by hand. It's hard to distinguish noises when the camcorder is so far away from the engine.


This is what I was wanting to hear:
http://tv.civicforums.com/?p=1118
This engine has 1 rod knocking.
Here is the thread:
https://www.civicforums.com/forums/2...driveable.html

Yours sounds 3 times worse from where you were standing, but it is hard to tell over the computer.

It sounds like it has pooped the bed.

Do you have the old oil filter? Cut it open, open up the filter element, look for metal trapped in it.

Hold the RPM at a little over idle speed so the knocking is loudest, and remove one spark plug wire at a time, listen for the intensity of the knock to change. Repeat for all 4 cylinders.

Ok here you go. Doesn't sound any different to me when reving [autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=1195& transactionid=1329593586-688415990&posted_by=G3rain1_www.civicforums.com&yo utube_video_id=X0R4FnfgqVE[/autostream]

After this i removed the plug wires one at a time. It rattled louder for each cylinder but I believe that is because the engine shakes a whole lot when on 3 cylinders.

I don't still have the oil filter though.

Got a stethoscope? A long dowel, a long screwdriver, a length of tubing, anything you can hold to various engine parts and stick to your ear. Stick it into and on places to find where the noise is loudest.


Maybe remove the belts and start it. Eliminate the alt/AC/and PS as possible causes.

Still noisy? Pull the timing covers, see if the timing belt has slack in it and the tensioner spring broke. Or maybe the water pump bearing let go.


Edit: I said plug wire earlier, it should say disconnect coils one at a time.

Unfortunately the adjustment bolts for the PS pump is rusted solid and the bolts head is rounded off. So I've been fighting with that and have been unable to remove the accessory belts. The hose trick seems to sound like its coming from the black plastic cover on the side of the engine which I'm assuming is where the timing belt is?

Yeah that's the timing belt cover. For the amount of noise it's making (and if that is the true location of the noise), I'm thinking the spring/tensioner broke or the water pump bearing is about to let go.
Anything making THAT much noise should be obvious once you have the covers off, and maybe have the timing belt off.

If I'm correct, then if it quits running--- it will be real expensive.

I had the timing belt done only about 15k ago. But the shop that did it has messed up other jobs as well which is why I no longer go there.

Do I have to remove the valve cover to get the timing belt cover off? It looks as if there is a lip on the valve cover that the timing belt cover hooks in to.

In the shop I don't remove it completely unless I'm adjusting valves at the same time, but you have to lift it up at the very least to clear the lip.

I hope you have a good service manual and plenty of tools if you are going to DIY this.

You might be very lucky that you still have an engine.

In case anyone want's to know, the culprit was a broken tensioner spring. unfortunately the timingbelt became damaged because of this and needs to be replaced as well.

that sucks i would sue the shop that f'ed up your tensioner possibly destroying your engine.

What kind of tensioner did you buy?

This is one reason I tend to go OEM on critical engine parts.

did you find this out yourself? or did you take it somewhere?