First off i drive a 2001 GT Mustang 4.6L V8.

My problem (If there is one) is that when i get into 4th gear and just keep going for a little bit maybe going 45-50 MPH it seems to shake a bit. Not the whole car, it just kinda jerks a little when i have my foot planted. Not quite sure what im doing wrong maybe the way im shifting? But i'm just going straight at the same speed and it wants to jump on me..

1st 2nd and 3rd are perfect and i dont feel anything but when i get into 4th it starts jumping... Not sure what it could be any suggestions? If you need any other info Let me know please im not sure what you might need to help, thanks guys.

 

Sounds like a misfire. Look at it and see if you can make it repeat it, and if it does it at the same time everytime. Like certain rpms, and does it do it in 5th also

 

When i get home tomorrow i'll let you know, but its anytime in 4th really.. When i get into 5th its good and doesn't jump on me at all.

 

Uhoh! how many miles on it?

 

About 85k...