The Lincoln LS was produced from 1999 to 2006 and is based on the Ford DEW98 platform. Unique in design from other makes and models the Lincoln LS still has all the same major components as other vehicles in the front end, all of which are subject to wear and tear. In some cases, depending on the year of your LS it is possible that any noise your hearing from the front-end could be under a recall notice and may be repaired free of charge. Regardless a noise in the front end is not normal and should be inspected and repaired immediately.
The ball joints on your Lincoln LS connect the lower control arm to the steering knuckle and acts as the lower pivot point for the suspension. Ball joints will naturally wear out over time, but are capable of lasting for a long period of time when properly installed and greased. The primary problem with a failed ball joint is that they generally are not available from the dealership or local auto parts store, so anytime the ball joint has failed you have to replace the entire steering knuckle. The easiest way to test for ball joint play it to lift the front of the vehicle off the ground enough that the tire is off the ground. Once the tire is off the ground firmly grab the top and bottom of the tire and attempt to push and pull, if the ball joint is bad there will be play in the tire. There is also a recall notice in effect due to improperly tightened ball joint nuts leading to ball joint damage and resulting in a “popping” noise. The TSB number is NHTSA00V359001 and is a hazard that should be inspected immediately if your experiencing front end noise.
The front stabilizer or sway bar is used to mechanically link the left and right suspension together to help level the vehicle and prevent too much suspension travel on one side or the other. Over time the sway bar bushings will wear out creating a metal on metal noise when the vehicle hits bumps or travels over rough road conditions. It is easy to determine if this is at least part of your problem through visual inspection. Support the vehicle on jack stands and view the area where the sway bar is mounted to the sub frame rails. If the bushings look weak, distorted or cease to exist you have likely found your culprit. Problem is the sway bar bushings are no longer available from the dealership and your not likely to find them in your local parts store either. The best repair is to replace the sway bar and end links with that from a 2003 and up Lincoln LS. The stock part number for the v-6 and v-8 base suspension is 3W4Z-5482-AA, the v-6 sport suspension is 3W4Z-5482-EA and the v-8 sport suspension is 3W4Z-5482-BA. Note this is a common repair that every LS owner will have to deal with eventually and most local repair shops also have no choice but to use the upgraded design from the new LS models.
If your hearing a humming while driving or a clunk noise while turning you may have a problem with your tires or steering linkages. An unevenly worn tire or a tire with a broken belt is likely to produce some annoying road noise that could lead you to believe there is something more serious going on. Of course a bad tire can be a dangerous thing if it goes out while driving, but at least you will still have the ability to steer and stop safely. Inspect around the tire, in general the tread level on the tire should be even across, a lot of inside or outside wear indicates the camber settings are off and a bulge indicates internal tire damage. In either effect, the tire or tires should be replaced and if you suffer from odd wear you need to have a front end alignment done as soon as the tires are replaced. There was a TSB released for 2000-2002 LS models that required the replacement of the yoke spring in the steering shaft that will create a loose steering wheel and may produce a humming noise. Luckily it would be serviced free of charge at your local dealership because it is a length job that isn't for the faint of heart.
If you're lucky enough to have an LS with sport suspension you have a slightly better ride over those with a base suspension setup, but both are still subject to wear and tear. Clunking noises from the front end could be the result of weak or broken struts, or a broken coil spring. The noise created from this situation would likely only appear when hitting bumps or cornering abruptly, but can cause steering problems and greatly reduces the quality of your ride. Visually inspect your coil springs, you will know if they are broke because they will be in two pieces. Push down on the front end repeatedly to produce a bumpy road effect and see if the noise duplicates itself. If you hear the noise at that point your likely in dire need of new struts. Any type grinding or growling noise can be attributed to the brakes or wheel bearing categories. If your hearing a loud grinding noise when you brake, or it gets worse when you apply the brakes you probable need new pads and rotors; hopefully it hasn't been going on for long or you may need to replace the calipers too. A growling noise will likely be a faulty wheel bearing. Drive at a speed of about 35 mph and roll down the windows. Try to listen towards each wheel to determine which wheel bearing is at fault.
