Help Diagnose This Engine Noise *video* (bearings?)

[Ski Bum]

I've had this strange engine noise for a while now. It comes and goes and oesnt seem to happen in a pattern. Today it was very loud and more noticeable then ever. The air temp was about 70* and the engine was cold. I can hear it when the rpms drop after revving the engine. The sequence goes: rpms increase, reach the point where I let off the gas (in this case about 2k rpms), they begin to drop back towards idling rpms, sound in question occurs. The sound to me is like a bunch of marbles rattling around in a can. Its a metal on metal noise that seem to come from somewhere in the upper end of the motor (bearings?)

Anyways, the sound is pretty noticeable in the video. Any help is appreciated.

Right click, save as:

http://www.onestopautodetail.com/images/Jason's Page/GSX impending doom.wmv

*EDIT* Also in the background noise of the engie there is a constant wah wah wah sound, any ideas on that one?

 

[Strm Trpr]

I'm pretty sure the only bearings our motors have are main, connecting rod and balance shaft bearings.

Do you still have your balance shafts in?
Perhaps it's the rear balance shaft grinding around in the bore.

Does the noise happen after the engine is up to operating temp?

Jack that biotch up on 4 jack stands and have someone rev it just like you did.
It really sounds like something is spinning and grinding at the same time.
Maybe clutch related, thats why I'm mentioning to get under the car and have someone rev the motor so you can listen under the car.

Check your harmonic dampener just in case it's coming apart.
Check your power steering fluid and the pulley, and check your water pump pulleys for any axial play in them.
Rev the motor and look at the belts to see if the move in and out.

You know what, after thinking about it for a little while, remove the upper T-Belt cover and see if the noise gets any louder.

You may have a bad or going bad idler pulley.

 

[91gsxdsm]

like he said check the harmonic balancer ( crankshaft pully) my car made a very slight noise similar to yours, two of my 4 bolts came out and sounded horrible. but that just sounded nasty...good luck !

 

[Ski Bum]

I'm pretty sure the only bearings our motors have are main, connecting rod and balance shaft bearings.

Do you still have your balance shafts in?
Perhaps it's the rear balance shaft grinding around in the bore.

Does the noise happen after the engine is up to operating temp?

Jack that biotch up on 4 jack stands and have someone rev it just like you did.
It really sounds like something is spinning and grinding at the same time.
Maybe clutch related, thats why I'm mentioning to get under the car and have someone rev the motor so you can listen under the car.

Check your harmonic dampener just in case it's coming apart.
Check your power steering fluid and the pulley, and check your water pump pulleys for any axial play in them.
Rev the motor and look at the belts to see if the move in and out.

You know what, after thinking about it for a little while, remove the upper T-Belt cover and see if the noise gets any louder.

You may have a bad or going bad idler pulley.

All of the timing belt related components have less than 1k miles on them. I cant imagine the idler pulley has gone out already?

Do you still have your balance shafts in?
Perhaps it's the rear balance shaft grinding around in the bore.

The balance shaft/belt/pulley are all still in with the belt and pulley having less than 1k miles on them. How would tell if that is happening?

The noise occurs mainly when the engine is cool but only randomly happens.

The water pump is also new which shouldnt be out already.

Check your harmonic dampener just in case it's coming apart.

What and where is the harmonic dampener?

I'll try the tests you reccomended and post the results. Thanks.

 

[Strm Trpr]

The harmonic dampener is the large pulley on the crankshaft.
There is a inner pulley the bolts to the crankshaft, and the a rubber sleeve, and then the pulleys that drive your accerssories like your a/c, water pump, power steering alternator.

Maybe it's a loose rocker arm, it's just loose enough to produce that noise when it's cold, but once it warms up, it's tight again.

If I'm not mistaken our engines have rocker arms that have a roller tip that follows the camshaft.
They have tiny needle bearings in them, if they get damaged, I could imagine that noise could possibly come from there.

How many miles do you have on that head?

 

[Ski Bum]

The harmonic dampener is the large pulley on the crankshaft.
There is a inner pulley the bolts to the crankshaft, and the a rubber sleeve, and then the pulleys that drive your accerssories like your a/c, water pump, power steering alternator.

Maybe it's a loose rocker arm, it's just loose enough to produce that noise when it's cold, but once it warms up, it's tight again.

If I'm not mistaken our engines have rocker arms that have a roller tip that follows the camshaft.
They have tiny needle bearings in them, if they get damaged, I could imagine that noise could possibly come from there.

How many miles do you have on that head?

I cant really say how many miles are on it. The chasis has 114k while the previous owner had the current motor swapped in a few thousand miles agao and he didnt know how many miles were on it. Assuming the guy didnt swap in motor with more miles than the previous motor it should be safe to assume it doesn't have more than 114K miles on it.

 

[Doug99RS]

It sounds alot like a pulley type bearing noise. Try removing all of the accessory belts and revving it up again. It could be that there is excessive tension on the belts as well which will accelerate wear and increase noise.

 

[StealthXtreme4]

I don't hear anything from the engine itself, it does sound like a rotational scraping. Check to see which of your pullies is failing.

 

[Ski Bum]

I don't hear anything from the engine itself, it does sound like a rotational scraping. Check to see which of your pullies is failing.

I recently did a full timing belt job and replaced the 3 main belt pulleys: idler pulley, balance shaft tensioner pulley and the timing belt tenshioner pulley. I also put in a new auto tensioner. The water pump is also new. I guess that narrows it dow to the alternator, power steering and crank pulley?

Can I pull the alternator blet while the engine is running to determine if thats the one?

 

[wolf20043]

Yes, you can pull the alt belt and start it up, it will just be running off the battery while you are running it so dont run it too long without, but it will give you an idea if it is accessory belts. I just dont know if I hear anything that is bearing related. Try pulling all belts off and see if it goes away. If it does, put 1 belt at a time on and try it and that should let you know which one it is.
Mike

 

[Doug99RS]

Can I pull the alternator blet while the engine is running to determine if thats the one?

Do NOT pull a belt while the engine is running.

 

[andytalon]

My car makes that same noise scares the shit outa me make sure when you done you post it I would love to know! I first thought it was my turbo, still havnt figured it out yet.

 

[Ski Bum]

Do NOT pull a belt while the engine is running.

Its cool, I really only need one of my hands

I should have worded that differently.

Yes, you can pull the alt belt and start it up, it will just be running off the battery while you are running it so dont run it too long without, but it will give you an idea if it is accessory belts. I just dont know if I hear anything that is bearing related. Try pulling all belts off and see if it goes away. If it does, put 1 belt at a time on and try it and that should let you know which one it is.
Mike

I'll do that and post back, thanks.

 

[wolf20043]

It sounds alot like a pulley type bearing noise. Try removing all of the accessory belts and revving it up again. It could be that there is excessive tension on the belts as well which will accelerate wear and increase noise.

Yea, I missed the wording too
Mike