Clangy noise from motor V6. With audio file attached

[balloonatic]

Greetings, I have a 95 model VR Commodore V6 and recently the motor has started getting very noisey. There is a clangy, clapp or it sounds like the lifters are shot and making the rockers rattle terribly but it sounds more than that like the balance shaft bearings are shot making it make a loud rattle. The noise isn't heard much over 1500 rpm but the lower the engine revs, the more rattle it makes.

Any ideas? It does sound more like the noise is coming from the top but it's still hard to tell with the noise so loud. I don't know where I should start. The motor still drives fine with no oil pressure loss.

Here is a audio file of the noise. The last 7 seconds of it was with the bonnet up.
2011-05-26 22:01.mp3

 

[accentstencil]

It's hard to tell from the audio file but have you checked the harmonic balancer for damage?

 

[balloonatic]

Hi, yes I've checked it. The car when cold doesn't make the noise at all. That noise only comes about when the car has warmed up. Couldn't have anything to do with the oil thinning?

 

[hako]

Remove the serpentine belt - then start the engine and run for no more than 20 seconds - if the noise has gone it will be either the harmonic balancer or one of the items that run off the serpentine belt. If the noise is still there it will probably be the balance shaft.

 

[balloonatic]

Thanks. Will try that. Is it safe to remove the gear off the balance shaft so it never spins?

 

[hako]

Apparently so - has been covered before. They simply remove the gear off the end of the shaft - you can also remove the shaft entirely but then you must block the oilhole at the flywheel end - not easy. Vibration may increase but it's a fair trade-off.

 

[BowTie]

i just had a similiar issue on a vs off ebay for 700.

Ended up being a combination of timing chain and a flat/damaged cam lobe.

 

[jzt4kikz]

sounds like a tinny noise man ?? something simple like exhaust ?