Engine running but belts and serpentine just barely spinning.
Tensioner is bad
I can move the belts easily with my hand while the engine is off, and all pullys turn. Was thinking crank shaft pully may not be secured to the shaft correctly… But i haven’t disassembled things to properly look yet… Any thoughts? Still think it’s tensioner?
Check the harmonic balancer if the pulley of the balancer is spinning on the hub because the rubber has delaminated.
Which one is it? I think it is 3.0 and 3.5. Multiple belts. Multiple tensioners. All the belts cannot be loose unless all the tensioners are bad. I don’t think so
3.5. i got in there and examined the harmonic balancer. The rubber looks ok from my initial exam. I’m thinking there must be a key that has probably sheared off internally. Going to pull the radiator and get to pulling the harmonic balancer next. Belt tension everywhere is fine, so I’m guessing it has to be a sheared pin. Thoughts?
Take a piece of chalk and mark a straight line across one half of the balancer and then start the engine.
Shut the engine off.
Is the line still lined up?
If not, the pulley of the balancer is slipping on the hub of the balancer.