ClubLexus - Lexus Forum Discussion

Lexus: Why is My Car Vibrating?

Unnatural vibrations are almost always a sign of a mechanical issue. Figure out what could be causing bad vibrations in your Lexus with these tips.

By Pizzaman711 - December 8, 2014

This article applies to the Lexus IS, ES, GS, RX (2005-2014).

If your car has a vibration when it's moving or still, this can be a sign of something faulty. Unfortunately, there are a lot of different components on your car that can cause the vibration. it's best to try to narrow down when the problem is occurring, whether it's when driving, braking, idle, or in park as well as the general area the vibration is coming from. The Lexus is an expensive vehicle with expensive parts, so if you have a warranty it's always best to consult a dealership first.

Materials Needed

  • Socket set

Vibration at Low Speeds, Idle, or Park

Step 1 - Check if the car is lowered

Lowering a car alters the angles of the suspension and drive line which can lead to a vibration. The AWD Lexus IS is notorious for this. This vibration is especially noticed towards the rear of the car and is sometimes described as the feeling of wind blowing against the car. Unfortunately the only fix is to raise the vehicle back up closer to stock height until you hit a point where the vibration disappears.

Figure 1. Lowered IS.

Step 2 - Check fuel injectors

They may be clogged or faulty. Leave this step to a mechanic if you aren't highly mechanically inclined. Normally, bad fuel injectors will trigger a DTC code and check engine light. However, this isn't always the case in the early stages of engine failure.

A temporary fix (and a quick test to see if this actually is the problem) is to put a bottle of Techron or another engine cleaner into the gas tank. This will help to clean out the fuel injectors. If you have fuel injectors that are dirty, chances are the throttle body needs to be cleaned as well.

Figure 2. Working and clogged fuel injectors, respectively.

Step 3 - Check for carbon buildup

A side effect of using direct injection engines in the IS 250 and 350 is the issue of carbon buildup. When driven placidly for extended periods of time, the burnt carbon residue from the combustion process settles on the injectors, valves, piston and cylinder walls. Overtime this can lead to piston damage which can require a major engine overhaul. Using low grade fuel or fuel with a high ethanol content can expedite the build up.

To avoid this, be sure to regularly drive the engine hard. The heat and high speed will burn the carbon deposits off and keep the engine running smoothly.

Figure 3. Excessive carbon buildup on valves.

Step 4 - Is there lean idle misfire?

The last option to consider is what's known as the "lean idle misfire". This is unfortunately normal and there's not too much that can be done to fix it. When you begin to get close to a complete stop and while you're at a stop, the car's computer lowers the amount of fuel going to the injectors. This helps cut back on emissions, but also puts your car at the borderline of misfiring due to not having enough fuel.

Vibration While Driving

During braking

Warped rotors and worn out brake pads are the number one cause of vibration during braking. The braking system works by pressing the pads against the rotors to build friction and slow the vehicle down. Every time the brakes are applied, a tiny amount of metal is scraped from the rotors and brake pads. The thinner a rotor is, the less heat a rotor can absorb. Heat from heavy braking will warp the surface of the rotor, making it uneven. The vibration comes from the brake pads applying pressure unevenly across the brake rotor surface. Replace the rotors with new ones if this is the problem.

Figure 4. Lexus rear brake rotors.

During normal driving

If the vibration occurs during normal driving whether you're accelerating or coasting, it could be caused by the tires or the alignment. These two problems can be more pronounced when driving at a specific speed. Rotating the tires is a good way to test them. If the problem moves from one area of the car to another, a tire is likely damaged or a wheel might be bent.

The alignment will need to be checked by a professional. If the tires are worn unevenly, chances are your alignment is out as well.

Figure 5. Lexus IS on alignment rack.

Related Discussions