Hello tomneu2002. It is as frustrating as it gets. I feel your pain. I wish I had better news but no I have not found the problem yet. It is still a work in progress. Since Sep 20011 I have performed a tune-up, new plugs, plug wires, air and cabin filters, cleaned Mass Air Flow sensor, throttle body. PVC valve etc. Replaced both front cv axles, 4 struts, right front and both rear strut tower bushings, right front hub and wheel bearing, both front control arms, control arms to sway bar link assemblies, both rear sway bar to strut link assemblies, rear sway bar bushings, front sway bar bushings, bottom rear engine mount, front brake rotors, pads and caliper guide pins, rear brake drums and shoes with new springs /and brake shoe mounting harware, rotated and balanaced tires numerous times to include 2 road force balance on a Hunter 9700 computerized road force balance machine, took to 4 different shops including Hyundai dealer and I still have the vibration. Granted it has improved since I started but still there and somedays worse than others. I feel it equally in the seat as I do the steering wheel. I mounted Hankook Optimo H727 tires in Sep 2011 and the 3 tire shops I tried said the tires are not out of round. Next is to go to auto craft shop, put car on a lift and inspect Rack, rack bushings and the intermediate shaft from steering to rack and pinion. I know everything is solid no play in ball joints, tie rods etc on both front and rear suspension, no rear wheel bearing hub assembly or spindle bent or defective etc. This one has got me stumped, and Hyundai USA customer service is no help. After I inspect the rack and find nothing wrong the next step is check Auto Trans torque converter bolts. Possibly flywheel out of balance, harmonic balancer or it is indeed the tires and if not then a design flaw with Hyundai Elantras 2004-2006 model years.
Tuesday, October 30th, 2012 AT 6:55 PM