Shaking at idle

[blitzin247]

Alright guys, ive searched some on this problem, but still need some help.

The truck ran rough this morning after sitting all night, so I changed the Fuel Filter, still ran rough, I got out my autocal and read balance rates all 0.2-0.4 in park. I check Desired vs actual FRP and they are within a few hundred. Truck felt like it had a slight miss up to about 1300rpms, checked, no codes, so dumped in some optilube and took it for a drive.

Shake started to calm down, and is unexsistent above about 1200rpms. I started to get on it some and the shake does not happen at higher rpms and the shake was not constant at idle after the five minute test run. Before the truck would shake constantly at idle, but after the drive it would shake a little only ever 5-10 seconds are so. The harmonic balancer seems to be in one piece and spinning with the motor as it should. There are no weird knocks, no fuel in oil. However on shutdown it makes a small metallic clunk noise, but only on shutdown.

So, whats the thoughts...broken crank, FR, Harmonic balancer, rods?

HELP!

 

[blitzin247]

I should also add, that every once in a while the actual FP would go blank on my autocal, then after scrolling back through my PID's a few times it would return to give me a what I assume to be a proper reading.

 

[Muff]

The injectors could possibly still be bad even if the balance rates are good. Who redid them?

 

[blitzin247]

they were done two owners back, pretty sure my injectors are good, no hazing, good balance rates, no fuel in oil, everything there is like they should be. But I did go to start pulling off my harmonic balancer tonight, and the bolt was coming off on its own, and I could spin it (the harmonic balancer) by hand. Will resume tearing off the fan and clutch assembly so I can get the balancer off on Monday. I am praying for just needing a new crank key.

 

[WI Huck]

Good catch! You may have saved yourself a ton.

 

[TheBac]

Balancer bolt loose? Man, thats not good.

Make sure to put something in front of the radiatior before you pull the fan off. You'll thank me later.

 

[blitzin247]

Update: I drilled the crank and balancer and keyed the crank... she runs smooth as ever now. All internals are fine

Now Im looking to get into a Powastroka :hello: