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Lexus: Why is My Car Whining?

A whining noise from your Lexus can be a sign of needed maintenance or that something isn't installed properly.

By Pizzaman711 - December 8, 2014

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

A whining noise can mean a variety of things aren't right. Some of the fixes are inexpensive, while others may have you considering selling altogether. Problems often turn expensive if left unfixed, so it's always best to diagnose the problem as soon as it arises. The first and most helpful thing you can do is find out where the sound is coming from and its cause. Pinpoint the area of the sound or the conditions that cause it (like accelerating or braking), and determining the source of the whine will be no problem.

Materials Needed

  • Socket wrench
  • Ground loop isolator
  • Belt dressing
  • Serpentine belt

Step 1 - Sound from the engine

A whining sound coming from the engine bay is more than likely a worn out serpentine belt. Normally the sound will also get louder the higher the engine is revved due to the belt turning faster. A very easy way to diagnose the problem is to apply some belt dressing to the serpentine belt. If the sound goes away, replace the belt. Another possibility is that the pulleys are worn out. Diagnose this by spraying them with WD-40. A failing Alternator will also whine constantly as they fail. Typically a failing alternator will also result in a dead battery or starting problems. Another possibility, although the least likely. is the timing chain. This will normally be more of a rattle sound but some people do describe it as a whine. This will need to be diagnosed by a trained mechanic and replaced immediately if found faulty to prevent further damage to the engine.

Figure 1. Lexus IS serpentine belt.

Step 2 - Sound from the speakers

You may have ground loop interference. A ground loop can be caused by an ungrounded audio connection which will pick up the electrical frequency from the alternator. This frequency is then transmitted to a whining sound through the speakers in the car, which will get higher and louder the higher the engine is revved. This issue won't normally present itself if the audio system is untouched; however, there is a current TSB out for a whining sound from the speakers while charging a device in the auxiliary port. If a new head unit or amp has been recently added, there's a chance your RCA cables have a ground loop issue. This is a relatively cheap and easy fix that requires plugging the RCA cables into a ground loop isolator.

Figure 2. Ground loop Isolator.

Step 3 - Sound from underneath the car

A whine that clearly comes from underneath the car is a sign that there is a transmission problem. Unfortunately, this is a worst case scenario because it'll require a transmission overhaul. If the transmission fluid is burnt, dark, or foamy this could be your problem. If something breaks down in the transmission, it can cause the torque converter to whine. This may only be apparent at certain RPMs or before the transmission fully warms, but eventually it will whine all the time. This is something you need to see a mechanic about immediately. Replacing the torque converter is a lot cheaper than the entire transmission.

Figure 3. Transmission fluid color chart.

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