Thursday, June 2, 2011

Harmonic balancer/serpentine belt problem?

About a week ago, I started hearing a rattling sound when I turned on my air conditioner. I took it to the shop to get the oil and fluids changed and asked them to look at it. They said my car was fine, but needed it's 70000 mile check up. Three days later, my electrical problems light came on and my ac died. About an hour later the car stopped running in the middle of nowhere. I managed to get back home, but my car is still in the town where I broke down and the mechanic is saying that my harmonic balancer and serpentine belt are missing. What is a harmonic balancer? Is it likely that it would just fall off? How much should it cost to get it replaced? I have no idea if I can trust this mechanic and no way to get a second opinion without paying for a four hour tow to a shop closer to home. Please give me some advice on how to handle this....Harmonic balancer/serpentine belt problem?
I'm not sure what type of vehicle you are refurring to. On all vehicles though, the harmonic balancer is the crank shaft pully. This turns the drive belt(s) On most vehicles they will come apart and lose the belt. What causes this on most vehicles, the harmonic balancer has a rubber dampener made into it. The rubber will get worn and break apart then the pully comes off along with the belt. They will cause a rattling sound before it comes off also. It will cause you to loose power steering, A/C, sometimes water pump, depending on vehicle, and alternator wont charge.Harmonic balancer/serpentine belt problem?
The harmonic balance is connected to the end of the crank shaft and is used to tranmit the power to the rest of your accessories through the serpentine belt.

Harmonic balances don't typically just fall off, and though it is possible as some of them have a rubber connection that fails, you definitely would have heard something if it had truly fallen off, not to mention probably have a hole or very bad dent some where in your car.

Odds are the serpentine belt was lose, maybe the tensioner is bad and the serpentine belt fell off. You'll need the serpentine belt to drive the accessories. It's possible that one of the accessories (ie, A/C compressor Siezed and caused the belt to come off)

How much is he charging? Obviously the first thing to try is to simply replace the serpentine belt and see if it works.

If replacing the belt appears to work, I would drive it home that way, but minimize my use of all the accessories. (ie don't use the A/C, minimize use of electrical items) until I determined why the belt fell off initially.