High rpm rythmic vibration, mid rpm hum.

[kraut83]

Check your air cleaner wing nuts for tightness. I had odd/loud/irritating noise that I ultimately traced to a loose air cleaner cover.
Also, it sounds like your cold advance switch may not be working and is stuck on. I can hear some hammering on the cylinders as your driving it. Does your truck go into high idle when first starting it then back down after it warms up? If not your cold advance could be your issue.

You sir have a good ear. Got the belts back on and unplugged the top plug on the IP green wire. The solenoid that's attached to the throttle cable arm and it runs significantly better. I have one from the old motor. How do I test if this one is good? Also on the chance the other one is also bad, I can go with out so long as the truck starts correct?

 

[cucvrus]

All I hear is a blower motor squealing and possibly some fan belts. I also know that delivery nozzles can stick on occasion and get a tapping sound. Sounds like a dry nozzle after you put the phone on the floor. Good Luck.

 

[dougco1]

You sir have a good ear. Got the belts back on and unplugged the top plug on the IP green wire. The solenoid that's attached to the throttle cable arm and it runs significantly better. I have one from the old motor. How do I test if this one is good? Also on the chance the other one is also bad, I can go with out so long as the truck starts correct?

The advance solenoid works to increase the fuel delivery/timing in the IP to help with starting when the engine is cold. If you run down the road while the engine is still cold and or with the IP fuel advanced it will run rough make your truck hammer like your banging on the pistons with a mallet. That's what it sounds like in your second video starting at 24 seconds in. It quiets down later in your test run as your engine warms up.

You can leave it unplugged and go without but your cold starting may be affected. The fast idle switch that controls the advance solenoid is most likely bad "lower passengers side block by the rear glow-plug"

 

[cucvrus]

Dougco1, that is an excellent observation. I used to like that sound when I was at the intersection a 1/4 mile from my house and pulled out in the winter. It sounded like the engine was coming out from under the hood with the timing advanced. I have since been less amused with the sound and am happy with the silence I hear in my Trail Boss. Happy Holidays and I have a present for you.

 

[dougco1]

Dougco1, that is an excellent observation. I used to like that sound when I was at the intersection a 1/4 mile from my house and pulled out in the winter. It sounded like the engine was coming out from under the hood with the timing advanced. I have since been less amused with the sound and am happy with the silence I hear in my Trail Boss. Happy Holidays and I have a present for you. View attachment 885256

Rick, your present is terrifying, just terrifying.

 

[kraut83]

Last update and I'll call this officially closed. Installed a new switch in the back of the motor passenger side. I've now put 100 miles on it and it drives much better. It's especially noticeable going up and down hills. On start up the idle is high, after its warmed up the idle drops down. This is a first, the switch was with out a doubt bad.

Thank you all for taking the time to go through this with me!