any answers, the car drives and shifts fine but when i slow down to anywere from 40 to 20 mph i get a vibrating from the floor what is that? i thought i need a tune up but if i needed that the rpm gauge would not be steady, thats not happening. its kind of like the car has bad gas or a spark plug is missing.

 

trying to figure out the same for my car, won't be able to do any work on it til spring. I think my culprit are the engine, tranny and diff mounts. Does your car vibrate while coasting in neutral?

 

dont know but i will try that and get back to u but that is funny because i just had my tranny serviced not to long ago and that is when it started happening.

 

hit me up 2052762515

 

This was happening to mine at one point. The culprit---upper ball joints! Also, check shocks, struts and also lower ball joints.

The other occasion that this happened to me, a spark plug popped out of place as you first mentioned. Once re-inserted, it was fine and never happened again.

It may not be your issue, but they are all worth checking.

 

try checking the driveshaft center piece and the bolts that connect to the diff

 

has anyone found out why our cars do this mine does it too???