Vibration

[xx88man]

I will do these. Thank you

[bdschnei]

One other thing that could be messing with you is a slipping harmonic balancer. The OEM balancer has a rubber isolator between the balanced portion and the center, and it's not unheard of for that rubber to decay and for the two pieces to slip, throwing the engine out of balance. If the timing mark on the balancer doesn't stay lined up with the marks on the timing tab like you would expect, maybe there's some slipping going on which would of course cause the weighted part of the balancer to shift.

 

[xx88man]

bdschnei thanks I will look for this as well...

[xx88man]

Just to eliminate it, try putting a timing light to it and check for timing fluctuation. Also check vacuum for fluctuations. this will eliminate tuning issues.

Vacuum seems low to me. Right around 13. It appears I need a new timing light 

[MoparLeo]

13lbs of Vacuum is pretty low. Is it steady or fluctuating ?

[xx88man]

13lbs of Vacuum is pretty low. Is it steady or fluctuating ?

Quite steady. I tried 2 different vacuum gauges and they both read about the same

[Brads70]

13lbs of Vacuum is pretty low. Is it steady or fluctuating ?

Quite steady. I tried 2 different vacuum gauges and they both read about the same

Depending on the cam that might be ok, mine has much less than that at idle.

[Brads70]

I have a 1974 Challenger 360 auto. When running I can feel a very noticeable vibration... stopped in park or neutral. I know it needs a transmission mount so my question is this. Can a bad transmission mount cause this vibration when the car isn't even moving? It seems to be a vibration that comes in waves.. rough for half a second then smooths out for half a second when I'm bringing up the RPM.

When you say " stopped in park or neutral " are you saying the vibration stops when in park or neutral ? Does it ever go away? If so under what conditions?

[xx88man]

I mean it vibrates even when parked. I haven't found a scenario that the vibration goes away