Good day all.
I read a post and it triggered a thought. Thus a question.

How do you know if you motors harmonic balancer is compromised?

Many parts can cause a "vbration" at higher than normal engine speeds.

Fan....
Water pump..
Power steering pump, a/c...altenater,
Pulleys and the such... So what about it?

 

When it does not read TDC correctly.

 

Thats the only sighn of a improperly functioning harmonic balancer?

 

For a stock damper, thats it.

 

Gorts -

Iowan is correct, considering what a stock balancer is.

Are you talking about high rpm or high speed?

Archer

 

Both .....the dampening "effect" is not altered by old cracked or hardened rubber?

 

Gorts -

If it's happening with the car stationary, you can rule out suspension and anything downstream of the tranny.

All engines vibrate, so the next thing to do is figure out if yours is vibrating abnormally or something is causing you to feel the normal vibrations.

Now it gets trickier.

Just off the top of my head:
1. Make sure all cylinders are firing in the problem rpm range. A simple inductive timing light can help there.
2. Do you have solid/neoprene engine/tranny mounts - they can transmit vibrations.
3. Next step might have to be to start replacing stuff. And that could mean anything from the dampener to the flexplate (torque converter).

Archer

 

Vibration Mostly....

 

I've had bad motor mounts ,old, give feed back. I've also had a bent rod drive me crazy looking for a vibration.

 

This was a great post.
The last rattel/ vibration that i found was a power steering pump. Loose in its mount.

This post was triggered by another
A 440 with a miss. He said it was in a boat but said the cause was a faulty harmonic balancer.