Strange Knocking Sound

[BogFather]

well i have noticed in the last little while that when in gear and in park, especialy in park i keep getting a loud knocking noise from under the truck. if any1 can lend any ideas that would be great thanks...

 

[gensic11]

damn midgets.. always playing games with people

 

[BogFather]

tell me about it, i hate when they come around

 

[gensic11]

 

[BogFather]

well just checked and seems as tho this little kid was under the whole time tryin to get my attention. guess i need to watch where i'm going a little more often

 

[h2osurf]

I have the same problem, got a mechanic stethoscope and traced it to the first "expansion chamber" (at least thats what i think it is) on my exhaust. Pretty sure its just a loose baffle in there.

 

[Kean_SHO]

I see this thread is a little old, but I have a similar issue on my 97. I just bought the truck... and got a great deal on it because they didn't know what the noise was. I don't mind putting the work into it because the rest of it is perfect.
Using a long screwdriver to listen to the motor, the noise on mine is coming from the motor right underneath the EGR valve. It is a clackity clack noise the goes away after it's been running for about 2-4 min. As best as i can figure, it's coming from the top of the motor almost under the fuel rail... but not in the valve covers (again... as best as i can tell).
The truck has plenty of power, and shifts perfect with the noise and without. The motor doesn't seem to have any signs of being out of balance. It doesn't knock or ping. It kind of sounds like a really really noisy butterfly valve. The last 2 tanks of fuel it was running 21-24 MPG (highway).
So... does this sound familiar to anyone??
Thanks in advance for reading my post and i appologize if i just hijacked the thread due to being a different issue altogether.

 

[Kean_SHO]

OK, after lots and lots of reading... does this issue sound like it could be the cam tensioner implosion issue???

 

[BogFather]

well i popped the hood the other day and sounds like the sound might be coming from the top of the engine, a guy i know said it might be a pulley that just needs lubing. gonna spray some lube on and see if that fixes it. will let every1 know when i do.....