I just changed my rims..front 2 have 205-50-15 Rear 2 have 195-55-15..swirlies.

Cant tell if its coming from the front or back but im getting this thumping sound when im driving..I took out all tires to check for bends or anything but there is nothing!! Tires are healthy and rims are mint. What could possibly be making the thumping sound while im driving??

 

isolate the noise between the front/back by driving over speed bumps at slow speeds if possible. Listen to the thump to see where it comes from. I am going to say struts....I know they have nothing to do with your wheel swap but tire wall height can change the intensity of road bumps.

 

Does the sound vary with speed, with road surface type, going over bumps, is it repetitive or random...etc?

 

check lugnuts, check splashguards, and did you have them balanced? can you go back to your old wheels to verify it is the wheels?

 

maybe the tires have a flat spots?