bad vibration coming from rear of car ¿fuel pump?

[Cobracanuck]

subscribing.....i am having the almost exact same problem. For me though, i only hear when i am making a turn, or when i am going from a complete stop. it does indeed sound like when a license plate rattles from huge woofers. Sounds like the rear end of the car is about to fall right off!

 

[1994Vib.RedGT]

if it was something inside the muffler would it not have a very metallic sound?? and also, I do not have the proper tools to get it up on jackstands, I usually use my friends stuff, but he is out of town, and there is no way in hell I am getting under the car while it is running, unless it is up on a lift.

 

[RFMustangGT]

yea, fuel pump makes the normal whine, i checked and the tailpipes or mufflers are not hitting the drivshaft or anything else. my dad seems to think that this has nothing to do with fuel pump though, he thinks something inside the muffler, but it is not so much a metallic clanking as much as a rough vibration that sounds like the license plate when it rattles if you have a stereo. is it passible that it could be something in the differential, or where the driveshaft enters the differential?

you said that even if you are stopped and rev the motor that it vibrates. if this is true then it rules out transmission, draiveshaft, and rear end. I'm almost 100% it is your harmonic balancer. our cars are sorda prone to have the rubber between the inside and outside hub break-down thus causeing the harmonics to go out of balance causing a vibration. thanks to physics, that vibrating car go from different places pending on which rpm you are at. when mine went out I would have things vibrate at different times at different rpm's. sometimes it's hard to see but look down at your harmonic balancer and see if there is rubber sticking out. even if there is no rubber sticking out it could have also lost a piece could have flung out or something could have hit it and knocked a chunk off.

 

[1994Vib.RedGT]

you said that even if you are stopped and rev the motor that it vibrates. if this is true then it rules out transmission, draiveshaft, and rear end. I'm almost 100% it is your harmonic balancer. our cars are sorda prone to have the rubber between the inside and outside hub break-down thus causeing the harmonics to go out of balance causing a vibration. thanks to physics, that vibrating car go from different places pending on which rpm you are at. when mine went out I would have things vibrate at different times at different rpm's. sometimes it's hard to see but look down at your harmonic balancer and see if there is rubber sticking out. even if there is no rubber sticking out it could have also lost a piece could have flung out or something could have hit it and knocked a chunk off.

The vibration is definetly coming from the rear of the car though, and to view the harmonic balancer, dont i need to take the water pump and timing cover off?

 

[CManT1914]

The vibration is definetly coming from the rear of the car though, and to view the harmonic balancer, dont i need to take the water pump and timing cover off?

Nope, it's the very bottom "pulley" that the belt wraps around (below the waterpump pulley). It's external mount.

 

[RFMustangGT]

Nope, it's the very bottom "pulley" that the belt wraps around (below the waterpump pulley). It's external mount.

like he said. just look for any damage to it or something that is working it's way out of the two hubs like rubber.