Flywheel Rattle at Idle, Serious Omen Or Annoying? (engine, cost, Lancer)

[shyguylh]

I am considering a "beater heater" old $600 car (Oldsmobile Silhouette, 2001?) for getting to work until February when we'll have more money. In trying it out, it seems OK except for a loud rattle at idle which the guy said is likely due to a plastic shield missing or loose from around the flywheel. The noise mostly disappears once you're moving, only occurring at idle, and it doesn't shake any that I notice.

I've done some research but I'm basically confused. Is such a rattle likely just annoying or a bad omen of something awful serious on the horizon?

[Vision67]

Likely a harmonic balancer failure:


https://www.youtube.com/watch?v=ruYX2S8THP0

[shyguylh]

Is that something one should fix immediately to prevent a catastrophe?

[Rivertowntalk]

It could be a bad omen, but it is impossible to tell until somebody takes a look at it. If you could post a video with sound, someone might likely know what it is.

[Vision67]

The part costs about $50 but you need a special tool to remove it.

The failure can cause the engine crank to decouple from the belt pulley.

here:
https://www.youtube.com/watch?v=vM-bz_oBuus

[GregW]

Without the balancer the crankshaft can destroy itself. These devices are used to dampen harmonic vibrations created by operating the engine.

[UpstateJohn]

IF it coming from the flywheel, as stated in the subject post, it would not be the harmonic balancer. If the noise souds like rocks in a coffee can, Id bet it is the torque converter. (Assuming its an auto.)

[Vision67]

My daughter's 2000 Oldsmobile Alero with the V6 did experience that failure. It made noise at idle, went away at higher RPMs.

I had it fixed. It was the harmonic balancer. I can't remember what it cost to be fixed.

[ukrkoz]

Well, if man can't tell if noise is coming from the front or from the rear, where flywheel is...... Maybe not a good idea to look into beater cars?