Motor sound, not the normal lifter or valvetrain noise.

I have this sound coming from the motor. Its a 2001 3.4l auto. I can hear it more in the cab than under the hood really. Its not a normal lifter or valvetrain "tick" its more of like a chug. At idle is slows way down, once you hit the throttle the noise either goes away or becomes almost silent.

I guess the only way I can describe it is its more of a cha, cha, cha.........cha, cha, cha..........cha, cha, cha. All my belts are tight, pulleys dont have any play, ive checked my fan. Everything seems to be tight.

EDIT:
So I started to tear it down today. I replaced the idler pulley, with no change to the noise. I then started to dig deeper and deeper. Well, the noise ended up being the timing belt. It was making the noise as it came over the camshaft gear. Everytime it made the pass around it on the left side, it would click, or make a quick sqeel. I then noticed that the belt had a few teeth missing off of it. So long story short, the truck is sitting in the garage without a belt or waterpump. Ill be replacing tomorrow. I hope everything is fixed when done!

The timing belt sounded like a rubberband when you stretched it. so i guess it was just flexing and making noise.

 

exhaust leak?

 

its def. coming from the motor. Its got a knock with the cha sound every once in awhile.

 

video added

 

Wow that sounds bad. Any CEL's or abnormal temps/oil pressure?

 

Nope, truck drives like normal. Only cel is for the cat. being bad, giving a faulty reading to the rear 02.

Oh, and the high static sound you here is my camera, not the truck lol. Just the knocking rubbing sound is the truck.

 

It almost sounds like one of the spark plugs is out/missing or something. But you would most likely have a CEL if that was the case.

 

Yea and the truck runs perfect! I hear it more inside the cab for some reason. When you hit the throttle, it goes away. Or in the morning, when its cold and the idle is high, its not there. its only once its warmed up and its at low rpms.

 

Where was the mic positioned for that? Was it in the engine bay? That sounds a lot like a fan belt or one of the pulley bearings.

 

I couldn't really tell, does the tick get faster with more revs?

 

I was in the engine bay with the camera.

the tick disappears when I rev the motor. I only hear it whne the motor comes down to idle.

 

Any updates? and Is the video not working for anyone else? from the discription I feel like I have a similar problem but I want to see this video first.

 

It's only an audio track. No video.

 

hmmmmm well when I look at it, there just the black box with a blue Q in the middle and a ? mark ontop of the Q. and there nothing to click on to play any video or audio. Maybe my computer doesnt support quicktime??

 

Does the sound disappear when you put it in drive? I had something similar but couldn't find anything in the motor. Then one day I went over a railway crossing and shattered my flywheel. A cracked flywheel sounded a lot like a noisy valvetrain but disappeared when I got the new flywheel installed.

 

It doesnt go away when its in drive. I have an auto too, by the way.

The only time i dont hear it is once Im driving, once it comes down to idle, the noise appears.

 

Well, I finally got under there today on lunch. I felt all belts and pulleys. The lower idler pulley has a lot of play in it. Now I know normally, the idler pulley will squeak when bad though. But im gonna pull all belts off tonight and fire it up for a few min and see if the noise stops.

 

Update on first post.

 

Good to hear. Your lucky it didn't leave you stranded somewhere.

 

How many miles are you at?