techsupport

Hello all, I hope someone has dealt with this problem before and has a solution. I have a 2004 Accord EX that has been a very dependable car until recently. The serpentine belt keeps coming off of the pulleys. So, I did what I thought would solve the problem. Thinking the tensioner was worn out, I replaced it will a new one along with a new belt and tensioner wheels. This did not solve the problem but at least it eliminates the tensioner as the culprit. Every time I put the belt back on I make sure that it is on each pulley and the grooves are lined up. I center the belt on the the tensioner wheel and it all seems good. Once I start the car the belt will immediately move on the tensioner to where it is just about to come off of the wheel. Eventually it will come off, however I still drive it and I frequently have to put the belt back on. The only thing out of the ordinary that I notice is that the crankshaft pulley seems to wobble a bit. I have no idea if this had wobbled in the past or not, but the wobble could be enough to make the belt move on the tensioner. About 8 months ago, I replaced the timing chain and removed the crankshaft pulley in the process but remember torquing it back on to spec so I doubt that it has come loose. The only thing I can think of to temporarily fix this would be to add washers and a longer bolt to the tensioner to bring the wheel farther out. This may be hard to accomplish since the tensioner bolt is reversed threaded and finding a longer one might not happen too soon. I have attached an animated gif and a You Tube video link.



<iframe width="560" height="315" src="https://www.youtube.com/embed/3f6YpvstbwY" frameborder="0" allowfullscreen></iframe>
https://youtu.be/3f6YpvstbwY

New and old Harmonic balancer next to each other.
The old harmonic balancer came apart while I wiggled it with my hands. This is what caused it to wobble. The wobbling is what made my serpentine belt slide off of the tensioner. There is a rubber band inside the balancer designed to take out some of the vibration. Luckily this didn't come apart when my wife was driving on the freeway at 3,000 rpms.

Alex Reiter

none of the pulleys are seized? if there is a seized pullet, the belt is going to come off.

techsupport

Alex, the pulleys were not seized. The harmonic balancer is actually 2 pieces of steel with rubber between the. If the rubber wears out the pulley starts to wobble making the belt slip.