Harmonic Pulley Noise xc70

Post by **darrylrobert** » 25 Aug 2020, 00:03

Got a whirring noise coming from my sepentine belt, used a rubber hose and its coming from the crank/harmonic balancer pulley.

Sound disappears when i remove the serp belt.

Belt and tensioner look in good condition.

Usually i would just go ahead and change both out but i need to cut costs.

Question is if i get a new belt and tensioner then find the noise is coming from the harmonic balancer??...do harmonic balancers fail in this way?

I describe it as a whirring but i guess its a intermittant (with engine revs) rubber squeaking type sound.

I have a spare balancer (pic) but CANNOT get that nut off....

: siezed nut harmonic balancer

Post by **oragex** » 25 Aug 2020, 01:36

How are the pulleys on the serp belt ? Gave each a spin by hand ? The AC compressor pulley is likely to get noisy past 100k miles (if the clutch plate was already removed it may get bent and also be rubbing).
Is the large timing belt cover maybe rubbing at the crank pulley ? Does the lower engine mount look in good condition ?
Maybe also make sure it's not from that metal line passing nearby.

Post by **jonesg** » 25 Aug 2020, 05:11

The small timing pulley cover can stay in place. I recently changed my timing gear behind the harmonic balancer, I didn't touch the cover bolts. If the balancer pulley is secure I'd look more at the serp belt tensioner pulley.
Spraying with water can reveal which one is making noise as its running.

Post by **abscate** » 25 Aug 2020, 05:36

A 30 mm impact is the way to get this off. Hit it with penetrating oil first and let it soak for a day