HELP!!! THUMPING NOISE during acceleration while turning left! wtf!!!

Venomous96Cobra · Mar 21, 2011

I was about to head to work at a stop sign at the end of my street, I turned left onto the main road from the stop sign! I step on it a little as I'm turning and hear a pretty disturbing THUMP, THUMP, THUMP... I immediately let off the throttle thinking my rear end just broke :angry4: I am right by my house so I decide I'm not gonna take any chances. I decide to turn around just in case. I make a right turn onto the next street, and I punch it, figuring if it's broke, it's broke I wanted to make sure that this is what it was before I do a rear end rebuild :angel4: regardless nothing happened, no noise :dontknow: the street is empty so I punch it, takes off like a bear :headbang: turn left normally, and nothing! turn left under with a bit of speed under me and once again THUMP, THUMP, THUMP :BangHead: Bring the car to a stop and do a burnout, get out and look, 2 wheel marks on the ground :angry7:

I am stumped!

I am thinking maybe wheelhop everything looked okay under the car sway bar etc... and the suspension with the exception of the quad shocks is pretty new!

I have to add that I drove to work hoped on the highway and did 70mph with no issues, noise, etc... so any suggestions would be helpful, im thinking of just replacing the quads which look like the original's that came new on the car :confused1:

mustangspartan · Mar 21, 2011

You only feel it in the rear nothing in the front?.. Is it a contunious thump thump thump rthythm or is it sporatic. I would find a parking lots go in circles (no donuts :headbang: ) and try both ways. One time with constant throttle and the other time with nothing at all even out of gear coasting. See where the sound is coming from and also see if your getting feedback like a shake or grinding feeling. When you find out what way it makes the sound then try it under light and moderate braking conditions. If its a continuious its a rotating issue if its sporatic is prob a suspension issue. I would say maybe your clutch plates are starting to go. Maybe adjustment on the sway bar?

Larius · Mar 21, 2011

It is one of two things in my opinion. Either your wheel is a little loose (re-tighten your lug nuts) or your ball joint is popping and will need to be replaced.

Ninety8stang · Mar 21, 2011

^ what he said could possibly be a hub bearing as well.

DropTopPony · Mar 21, 2011

When my ball joint went bad it made that thump noise. You sure its coming from the rear?

Venomous96Cobra · Mar 22, 2011

coming from the rear! ball joints are new! I just replaced them less than 3 months ago...

mustangspartan · Mar 23, 2011

I was thinking bearings also but bearings would be continous it would get louder when putting pressure upon them but you would still have a little humming noise. If it is the clutchs in the diff its when they are trying to lock together while under load to the one side.

Need a little more to go on then a thump in the rear.. Any new news on the sound