1997 Z71

iTrader: (1)

Is this the water pump?
It started with the Air Compressor having a bad bearing. I removed it and replaced it with an AC Delete pulley. Now I hear this noise. The first video is a little more noticeable. In the second video it is getting louder and faster. The serpentine belt is removed, so it can't be the power steering, smog, belt tensioner, or alternator. It has seen a fair share of driving in the rain this season. The OEM water pump and MSD opti were replaced about four years ago.

Can the noise be something besides the water pump?

Any help greatly appreciated.



http://www.youtube.com/watch?v=TuOLG..._order&list=UL

http://www.youtube.com/watch?v=bQOwx..._order&list=UL

davorocks

best $4 you can spend right now.

http://www.harborfreight.com/mechani...ope-41966.html

i am betting on the water pump being bad

1997 Z71

iTrader: (1)

BAD NEWS

This morning I pulled off the water pump. The black wheel bearing grease, from 4 years ago, was still in the water pump coupling. The inside of the pump was spotless and the impeller spun by hand with the proper amount of drag. I started the Bird with the water pump off the motor and the noise is still there.

Looks like it's time to pull the balancer, and Opti. I am not sure if it is one of the three seals in the timing cover or the opti making the noise.

Can anyone "Name That Noise"?

draggin97s10

iTrader: (2)

pull the belt off?

SS RRR

iTrader: (2)

You should have pulled the belt off first and started up the car. Would have saved you a lot of trouble. My guess is idler pulley, but as suggested, an auto stethoscope is a good thing to have.

96TransAmboosted

iTrader: (8)

Drag read better the belt is already off the car. Sounds to me like a loose rocker arm that gets louder when the oil thins out. When you raise the.rpm a bit I bet it knocks or clicks faster.

96TransAmboosted

iTrader: (8)

He already said the.belt is off. Watch the.clip there is no belt on the.car. **** pay attention

SS RRR

iTrader: (2)

Yeah didn't get that far before watching the vids.
It sounds like a prairie dog is loose. Especially in the first one. If there are guideplates my bet is you have a pushrod making contact and/or oil supply to the top end or that specific rocker/pushrod combo is inadequate.

quik95lt1

iTrader: (7)

yeaaa.......i would def stop running it untill you find it.......it sounds like some mechanical interference inside the motor.....if thats the case you dont want to send metal shavings through the motor.......so dont run it......start at the top and start taking things apart.......with that kind of noise you WILL see where it was comming from........start with rockers/guideplates and pushrods.....

AChotrod

iTrader: (17)

I was thinking push rod on guide plate contact also. Either that or you have a baby bird trapped in your engine.

96TransAmboosted

iTrader: (8)

Is the car stock or not. If stock then no guide issues. Im putting my money on loose rocker arm. But hard to tell on my phone what the sound realy is or where it is coming from.

SS RRR

iTrader: (2)

It's not a tap. It's a squeak. It seriously sounds just like a prairie dog. When a rocker arm is loose it doesn't make noise intermittently like in the first video.

http://www.youtube.com/watch?v=TuOLG...layer_embedded

http://www.youtube.com/watch?v=Ouml1...eature=related

http://www.youtube.com/watch?v=YjFA8...ure=grec_index

ZFreie

^^^ Thats some funny ****.

Hackscamaro

sounds like it could be a cam going flat i have heard several that sounded this way. sounds just like a belt chirp but louder. first thing i would do is pull the valve covers and see if you can pin point where the noise is from and then check valve lash if still nothing then swap push rods and rockers with the one next to it and see if the noise moves if it doesnt pop the intake off and take a look at the lifters and i bet you find your problem

1997 Z71

iTrader: (1)

That Prairie Dog **** is FUNNY.

I did have the passenger side valve cover off and I was unable to find a smoking gun. The valves lash could use an adjustment, but they are close. Can a lifter in need of a minimal adjustment make that noise. I have LT4 stock 1.6 rocker arms. No guide plates. With the cooling system out of commission I have only ran it a 3 times for about 15 seconds at a time.



At this point, it is already torn apart, I thing that I should go after the opti and seals. I would hate to put it back together, chasing valve lash and find out that is the opti of front cover seals.

ANY MORE SUGGESTIONS GREATLY APPRECIATED


11.9 @ 117 at the 1st Annual LA Invasion. I hope not.

gatorhead

iTrader: (4)

The air pump/smog pump is not belt driven so it could be that, the only other thing moving externally would be the rotor but you would have noticed that performance wise.

SS RRR

iTrader: (2)

Torn apart as in you've taken the pushrods out and looked at them as well as the guide plates?

quik95lt1

iTrader: (7)

like i said a before man.........just keep taking it apart.......eventually you're going to run into it.......and like i said with that kind of noise you'll see it........its possible it could even be a bad cam bearing......keep on going and like i said id take it easy on running it.........drain the oil and see if there are any contaminants in it.......

Hackscamaro

use a stethoscope and find where its the loudest at. i seriously doubt its a seal though i have never heard one like that anyway doesnt mean its not possible though. i agree with quick 95 though keep takin it down you will find it and will know when you find it with a noise like that.

squeals99

iTrader: (8)

first time i've heard that noise that sounded identical to my problem... and there were metal shavings all over the inside of my motor... pull a valve cover off and i hate to say it but i bet you are in the same boat i was in... i'll find the problem this weekend when that motor comes out of my car, but pretty sure its in the bottom end... lifters and rockers and everything in the top end were all perfectly fine looking, but there was metal everywhere

i swapped lifters, pushrods, and rocker arms and still never went away

i'll give you an update on how the bottom end looks this weekend when the motor comes all the way out though to give ya an idea