Is there such thing as out of balance (engine, AC fan, etc.) that cause rough idle?

[Dantheman1540]

throw trans mounts in there as well. Its plausible.

 

[Doubeleive]

Since the level of vibration changed slightly with the AC off which is run of the belt drive system I think we might be getting to the right spot. I would take the belt off completely and start it for just a minute or so. Water pump obviously won't be running so you don't want to run it long enough for it to get hot. However if the vibrations change more then the only accessory item that could cause it would be the harmonic ballancer. If it was a fuel pump or injector issue I would assume you would see a code for missfire or O2 sensors reading lean.

uuuuhhhhhh, how would the water pump not be running if the ac belt is off? lol

 

[Dantheman1540]

uuuuhhhhhh, how would the water pump not be running if the ac belt is off? lol

You know what you totally got me on that one! I forgot they have their own dedicated drive belt.

 

[Doubeleive]

@dvzzz the ac pump has it's own dedicated belt, no tensioner it is a stretch belt you can purchase a small tool that is magnetic and sticks on to the large pulley (harmonic balancer) and it has a groove that pushes the belt off as you turn the pulley with a socket wrench. you can just leave the belt hang while testing to see if the vibration goes away. It is recommended to replace the stretch belt with a new one if you remove it but I think if the belt is not that old you will probably be fine just putting it back on using the same tool in reverse.

 

[Doubeleive]

You know what you totally got me on that one! I forgot they have their own dedicated drive belt.

I figured you were thinking back just a little to far lol

 

[Dantheman1540]

I figured you were thinking back just a little to far lol

I was thinking of a 2003 Taurus I just did an AC delete on when the compressor seized. Occasionally I do slumlord style mobile mechanic jobs

 

[OR VietVet]

Did the a/c belt go single, either with it's own tensioner or the stretch design from 2000 on?

 

[Dantheman1540]

Did the a/c belt go single, either with it's own tensioner or the stretch design from 2000 on?

For GMT-800 it has its own dedicated belt with a tensioner. However the tensioner sucks and on my RCSB with the super charger it usually slings the AC belt anytime It gets bounced off the rev limiter which is frequent. So I swapped to the GMT-900 stretch belt and my problem was solved. IDK what the KT2xx trucks have but I assume stretch belt.

 

[OR VietVet]

My 02 Tahoe has the single belt with the tensioner and I had done the tensioners. idlers and belts about a year ago. I was just curious if the 1999 and older rigs had the single belt or not.

 

[smokey_mountain]

I paid $1200 for dealer to install both engine and tranny mounts replacement, and he took time to properly reseat the mounts after the replacement.

throw trans mounts in there as well. Its plausible.