A follower will make the noise through out the rpm range.

JMC

 

Will a rocker arm also make the noise throughout the RPM range?

 

New Information...

Driving home last night I was cruising at about 60-70. Just stepping on the accelerator enough to maintain speed. I was also maintaining the noise. I turned the O/D off and the noise stopped. Turned the O/D back on and the noise came back. The rpm's were changing but the accelerator and speed did not. I was able to get the noise with the O/D off, but at a different rpm.

 

I don't mean to confuse the issue even further but this thread reminded me of a very similar situation I encountered.
In 1981 I bought a brand new 5.0 mustang. The first year for the H.O. V-8.
I drove it for a year with what sounded like a "ping" noise (detonation).
Being a motorhead, I was concerned by the noise but after many return trips to the dealership, I was told that it would go away as the engine broke in.
Well, after a year and many visits to the dealer AND some independent garages, I finally convinced Ford to take a GOOD look and fix the problem. They started digging, and a week later they found the problem. They found that the crank had 3 different size rod journals. What we were hearing was a very faint "rod knock".
They were as surprised as I was. If we had let it go it could have been catastrophic, but because I kept after them to get it correctly diagnosed, the crank was replaced and I never heard another bad sound from that car (until I totaled it on black ice a year later).
Keep looking for a cause. Some of the ideas that have already been mentioned can be easily done by you but it may take some more serious diagnosis that only the dealer has the equipment for.
I wouldn't recommend driving your rig without the belts on but you could start it up and see what you hear at different RpM's.
I hope this helps and that your problem is not as severe as the one that I had.
Good luck,
Lonster

 

Given the latest info you provided I would make sure the torque converter bolts are all tight. They make a knocking noise when they are loose.

I tried that with mine. I am convinced I have the one Ford built to test detonation and how much could occur before disaster motors.

I have spent so much money on mine I believe it will be cheaper to hope the noise never stops.

tom

 

Well everyone...I am screwed. On first listen Ford says it's a piston or rod and it's gonna cost between 1500-3000 and that's with them splitting the cost. Any ideas?

 

I don't believe them!

Do not let them do any work or half way tear down your engine without an absolute diagnosis.

Get a second opinion and do not tell the second shop what you think it is.

Good luck-

 

They wanted to charge me $500 to tear it down to be able to diagnose it and then another $500 to reinstall it. They "estimated" an additional $1500-$2000 to repair it if it could be repaired or another $5000 if it needs a new engine.

 

JJ run for the hills!!

I have heard that crap from so many different dealers I would swear they are trained to sell that!!! And not once was it what they "Thought" it was.

Trust me there are reputable dealers out there that will give an absolute diagnosis.

I would ask that dealer of your to tell me exactly what tests they did to determine that they needed to tear your engine down. Did they test all other options? I will bet that they will say we have heard this noise before and that is what we think it is.

If a dealer or shop for that matter ever says "we think that is what it is" GO SOMEWHERE ELSE!!!!!

Remember a lot of these dealers have been in business a long time and they still do things the old way which in this day in age is the wrong way! Almost nothing applies as it did just 10-15 years ago.

sorry for the long rant this stuff really gets to me.

bottom line is that yes it could be your bottom end but it is doubtful.

I wish I could do more to help.

Good luck-