Rattle at front of engine - harmonic balancer

[RossGN]

Trying to run down a rattle at the front of engine. Is most prevalent when A/C is switched on. A/C guy says not compressor or clutch....he thinks loose bracket somewhere - exaggerated when there si a load on the belt. I have the intercooler off for cleaning and painting. Cannot find any loose brackets or bolts anywhere. Pulled the intercooler fan to inspect the harmonic balancer. Balancer looks ok visually. Any way, other than visual, to determine if the balancer is bad? Is TTA balancer same as GN?

 

[bogies87]

You might try having a different A/C guy look at it. If it rattles when the A/C is on, probably the compressor.
Start the car with the accessory belt removed. See if it's still rattling. If its not put the belt back on and listen with a stethoscope to pin point problem.

 

[RossGN]

You might try having a different A/C guy look at it. If it rattles when the A/C is on, probably the compressor.
Start the car with the accessory belt removed. See if it's still rattling. If its not put the belt back on and listen with a stethoscope to pin point problem.

Thae rattle is there with the compressor off...seems like either the load on the belt or the increase in viabration when the compressor kicks in, makes the rattle louder. Really seems like the engine shakes more when the compressor kicks on. Not quite as smooth under acceleration as I remember my GNs, either. Runs strong, though.

 

[JimP]

I would look at the belt tensioner pulley.

 

[RossGN]

I would look at the belt tensioner pulley.

The tensioner was my first thought, but the pulley spins smoothly-no wobble.

 

[Blazer406]

Take the belt off and see if you can try and turn the motor by hand on the crank pulley...... back and forth......... it won't take a lot of force..... you are trying to see if there is any "slop" in the keyway of the harmonic balancer.

 

[RossGN]

No slop in the balancer...feels completely tight (this was the most stubborn intercooler fan I ever had to remove, though)

 

[Blazer406]

Just for giggles.....jack the car up and slide under and inspect where the converter bolts to the flywheel..... if this gets loose, it will transmit vibrations/noise that are hard to tell where they are coming from...... all you do is try and turn the converter back and forth..... if it is loose you will see the converter move and the flywheel won't......

 

[trbojo]

The tensioner was my first thought, but the pulley spins smoothly-no wobble.

even though the pulley checks good, the spring inside could be deteriorating and making the noise...if you look at it closely while someone engages and disengages the ac, you might be able to see it moving and changing in relation to the noise...