1994 Dodge Shadow

Please specify which engine you have. It makes a difference.

Is the vibration related to the loud sound? Do you feel it when the car is standing still? If the car has to be moving, do you feel it in the steering wheel, the seat, or both? Did you replace these parts in an attempt to solve the problems or did the problems start after replacing the parts? Was the battery recently disconnected or run dead?

Let's try to diagnose the problem rather than throw parts at it. Eveything you replace or change adds another variable that can add confusion to the original problem.

Caradiodoc

The Check Engine light is an important clue. Once it turns on, a diagnostic fault code has been memorized in the engine computer. If the problem doesn't occur again, the code will be erased automatically after about 50 starts, so it's important to have the code(s) read before that valuable information is lost. The code refers to a circuit or system with the problem, not the specific part.

Again, do you feel the vibration when the car is standing still? If so, that leaves out anything related to the brakes, steering, tires, or suspension systems. The vibration could be an engine misfire which could be related to the Check Engine light.

If the car must be moving, a vibration in the steering wheel that only occurs above around 45 - 50 mph could be a tire out-of-balance. At real low speeds, a bent wheel or broken belt in a tire could be the cause. If the vibration is stronger when braking, suspect a warped brake rotor.

Caradiodoc

If the vibration occurs during braking, the new rotors are likely warped, (not defective).

There are a lot of replacement parts around that were made in China. Any part made of cast iron must be "aged" for 90 days before the final machining. The Chinese rotors are perfectly fine, but they don't allow them to age. They just cast 'em, machine 'em, and ship 'em. They age on your car and will often warp when they're fairly new. One light machining will usually be all that's needed once they're done warping.

Caradiodoc