2018 Lexus LS Idler Pulley Issue


The following study used data made available to CarBeast, provided by our data partners.

Our analysis suggests that the 2018 model year Lexus LS has more idler pulley replacements as compared to its other model years, and other comparable vehicles in general.

The serpentine belt idler pulley rides on, and provides tension to, the serpentine belt. The most common indicator of a failing idler pulley is noise originating in the vehicle engine area.

Serpentine Belt Idler Pulley
Serpentine belt idler pulley

The cost for replacing the idler pulley is about $170 but can vary depending on:

  • Zip code
  • Use of OEM vs aftermarket parts
  • If the repair is performed at a dealership vs third-party repairshop

CarBeast Data

CarBeast uses repairs data from various repair locations across North America, sourced from our business partners. Our database has hundreds of millions of repair records across most vehicle makes and models.

Using NLP technology, CarBeast automatically understands the content in each repair record. Our data shows about 150 cases of idler pulley replacements for the 2018 Lexus LS alone, and 722 cases across all Lexus LS model years. Here’s an example of a relevant case :

Idler Pulley Coded Example
Example repair record of an idler pulley replacement on a Lexus LS

The left pane shows the notes (provided by the technician at a dealership) that describe the complaint, cause, and correction. The right pane shows the structured repair code (“Replaced Serpentine Belt Idler Pulley”) automatically extracted by NLP technology.

Several records trace the root cause to the bearing inside the idler pulley. Here is one such example

Idler Pulley Coded Example
Repair record describing the idler pulley bearing

Results from Diagnostic AI

Together with the data and NLP technology, predictive and diagnostic models power CarBeast Foresight and CarBeast Insight.

When using CarBeast Insight to diagnose a problem like “High pitched engine noise” for a 2018 Lexus LS, it suggests an idler pulley replacement as the 2nd most likely repair.

Engine Noise diagnosis for a Lexus LS
Differential diagnosis for an engine noise problem on a 2018 Lexus LS

Further Analysis

A closer look at the data reveals two trends. First, the 2018 model Lexus LS show a far greater percentage of idler pulley replacements compared to other model years of Lexus LS. Note that Lexus began its fifth generation of the LS with its 2018 model year.

Lexus Idler Pulley Replacements broken down by Model Year
Model year distribution for idler pulley replacements vs all Lexus LS repairs

Secondly, the issue appears to arise early in the life of the vehicle. Prior models of the LS usually do not show this repair arising early in the vehicle life. The chart shows that for the 2008 model Lexus LS has hardly any idler pulley replacements in the first 30K miles. However the 2018 model appears to need that repair early in its life.

Lexus LS 2008 vs 2018 Idler Pulley Replacements
Mileage distribution for 2008 Lexus LS vs 2018 Lexus LS idler pulley replacements

Reports from Lexus LS Owners

Besides repairs data available to CarBeast, we checked other sources for similar reports and incidents.

The website Clublexus for Lexus owners to share news, advice, and to ask questions. Here are a couple of threads from those forums about idler pulley replacements. These threads seem to corroborate that the issue occurs fairly early in the life of the 2018 model year vehicles, and that the idler pulley bearing appears to fail.

Clublexus Forum Post
Source - Clublexus
Clublexus Forum Post
Source - Clublexus

Recall Status

As of Jan 5, 2023, based on recall information available at NHTSA’s website, there does not appear to be a recall associated with this problem.

CarBeast’s studies are provided “as is”. For further information please read our Terms of Service