Weird noises coming from engine bay

[ND4g]

I have a weird clicking or clacking sound coming out of the engine area. I started hearing it mostly when I am along side another vehicle while sitting at a red light.
I opened the hood to give a close listen and also notice that it is NOT constant, and I cannot determine for sure that it may not vary with engine speed. Except for the roar of the engine when I rev it, again, I am not sure, but I think the sound goes away at higher RPM.

Thinking that it was a constant speed sound, and not varying with engine speed, I thought maybe I was losing my fan, or something was lose and occasionally hitting the fan. I disconnected the fan as a test, and the sound was still there.

I did a little more research and now think it may be coming from the Serpentine belt, or that area. Possibly, the Belt Tensioner.

Any thoughts? Guidance or advice to help nail down what the issue may be?

FYI - The belt was claimed to have been changed by the previous owner about a year before I purchased the car, and I have the car now for 5 years this February. I have put about 20,000 miles on the car in my almost 5 years of ownership. (< 117K).

Also, since I may be changing the belt this would be a good time to replace the AIR Pump with the AIR Pump Delete bracket/pulley kit.

--Rich

[raidmagic]

Could be a small exhaust leak.

[wildcatlock]

Originally Posted by ND4g

I have a weird clicking or clacking sound coming out of the engine area. I started hearing it mostly when I am along side another vehicle while sitting at a red light.
I opened the hood to give a close listen and also notice that it is NOT constant, and I cannot determine for sure that it may not vary with engine speed. Except for the roar of the engine when I rev it, again, I am not sure, but I think the sound goes away at higher RPM.

Thinking that it was a constant speed sound, and not varying with engine speed, I thought maybe I was losing my fan, or something was lose and occasionally hitting the fan. I disconnected the fan as a test, and the sound was still there.

I did a little more research and now think it may be coming from the Serpentine belt, or that area. Possibly, the Belt Tensioner.

Any thoughts? Guidance or advice to help nail down what the issue may be?

FYI - The belt was claimed to have been changed by the previous owner about a year before I purchased the car, and I have the car now for 5 years this February. I have put about 20,000 miles on the car in my almost 5 years of ownership. (< 117K).

Also, since I may be changing the belt this would be a good time to replace the AIR Pump with the AIR Pump Delete bracket/pulley kit.

--Rich

Look over belt and pulleys well. I have seen a small rock get stuck in the grooves and do the same sort of thing. Might also be a valvetrain noise. At 117K they need at least an adjustment and usually about ready for a new cam and lifter set. The old flat tappet set up doesent last near as long as the more modern roller does. Hard to tell for sure where it might be coming from without being there but these two would be a start. A valve adjustment would only cost you cover gaskets and would be good maintenence anyway.

[ND4g]

Originally Posted by raidmagic

Could be a small exhaust leak.

Hmmm. Would never have thought of this. How do I check this out? What do I look for?

Originally Posted by wildcatlock

Look over belt and pulleys well. I have seen a small rock get stuck in the grooves and do the same sort of thing. Might also be a valvetrain noise. At 117K they need at least an adjustment and usually about ready for a new cam and lifter set. The old flat tappet set up doesent last near as long as the more modern roller does. Hard to tell for sure where it might be coming from without being there but these two would be a start. A valve adjustment would only cost you cover gaskets and would be good maintenence anyway.

Since the belt is at least 6 years old, I guess I can change it out, considering the cost is so little to change vs. the cost if it breaks while I am out driving.
I doubt the valvetrain, I mean other than a mechanical failure related to it... The heads and all related was rebuilt by the previous owner when the car was about 80K miles, or so he said when I was buying it from him.
Plus, I bought a set of polished aluminum valve covers which I had my mechanic put on for me about a year or so ago, and if there was anything happening in there, I know he is good enough, that he would have told me.

[ND4g]

Hey guys,
I found it to be my alternator. An interesting symptom... apparently the bearings in the rotor assembly was starting to go bad.... there were no electrical symptoms as most would expect, but the intermittent noise that I previously described earlier in this post.
So with new alternator, I also changed the serpentine belt and Belt Tensioner, and while at it, the A.I.R. Pump delete pulley kit.
With all the parts on hand I went at it....
The belt was too big!!!
I took a closer look and sure enough the pulley on the AIR delete kit was a little smaller than the pulley from the original AIR Pump. There was not enough adjustment to compensate, and had to scramble and get another belt locally. After reviewing the site I purchased the belt from, I did see that there are two different sizes.
Is the two sizes because of the AIR Pump delete kit, or did I actually order the wrong size belt to begin with? Were there other issues that I was not aware of on my car that I will need to know if the new belt should break, or down the road when it comes time to order yet another one?
--Rich