Engine noise
 

Since late last fall before stoage, everytime I had a cold start, the was a noise for about 1-3 seconds in the motor

Then, it always stopped

It is like a steady "clunk, clunk clunk clunk clunk" very loud and a bit of a hollow sound to it I guess you could say

I havent had her going today, but I will take my camera out today and if it does it again, take a video of it so you can hear first hand!

Yesterday while at a buddies house, we were fooling around with the cars in the yard, and when I started it, THE NOISE REMAINED...This went on for about 4-6 starts....It did not go away

After driving it a while it disappeared, and even after idleing once for 7-8 minutes in disappeared! (until the next start up)

He is a mechanic for a GM dealer and he could not place the noise

We even worked the pully adjuster back and forth and it did not help (as it sounds like its coming from the front part of the motor)

Then we took the belt off and started it up, the noise remained...(maybe slightly quieter but it was still there)

Then as I say, the noise after the next start up, and a while of idleing, it completely disappeared...

It sounded internal, but what internal would go away after driving or idleing for 5-10 minutes???

Might it be a pump getting bad???

Harmonic Balancer?

Has anyone else had this problem and what are some opinions?

THANKS!!!

Also, started it a few times after we were screwing around with it, as I had to go into town, it did not do it upon starting etc, anymore that evening...

Get a video up.That would help out as it could be a number of things.

Its not doing the steady noise fr minutes now like that spell it took a few days ago

But I might be able to get a video of the noise it makes for several seconds after start up as it is probably the same noise

I will try and get it up today

Do you have any opinions on what it might be before hearing it?

Might it be the oil pump getting bad?

Sounds like the harmonic balancer has spit the rubber out and is clunking around till it picks up speed......what car is it year/model/engine??

2004 gt 4.6 sohc
100,000km

10-4 on the Harmonic balancer

I have had a car do this to me before, and when a harmonic balancer goes bad, it creates the weirdest clunking noises

My buddy had a similar problem with his 3.8L. Turned out there is a bushing on the cam position sensor that was making the noise. Might try that.

I had the same thing. The engine would knock at cold start every so often. It only happened once in a while. I changed the cams, intake and heads and the noise has never come back. I think it was something in my heads like a loose valve guide or something. Just my 2 cents.

Is it fixed yet?