Clean throttle body on Lexus IS

Hello guys.

Today, I brought my 2018 Lexus IS AWD in for an oil change and was told that my drive drive belt was found glazed and needs to be replaced ( $ 240).

Also necessary they said is to clean the throttle body ( $ 175).

The car is at 47k miles.

Do you think it’s oddly soon to perform these services ? I don’t mind them. Just thought a drive drive belt would need to be replaced around 60,000 to 100,000 miles.


Are these services being done at a Lexus dealer?

At a Toyota dealership.

Even if these services are needed, the cost is just too high. I’m sure the retail price of the belt is less than $25 (and I am talking at a local auto parts store…RockAuto would be even cheaper), and the cost of a can of carburetor cleaner or brake cleaner is less than $10. I am not seeing $380 worth of value for the hour or less of labor needed to perform these services. I would DIY and save nearly $400.


I agree. The prices are outrageous. Sadly, I can’t work on cars.

A glazed drive belt indicates that it slips. Have you heard any screeching from under the hood? If not, the belt is likely OK.

Do you notice any performance issues with your engine? If not, the throttle body does not need to be cleaned.


In as much as your vehicle is out or near the end of the drive train warranty I suggest you look for a good independent shop, non-chain (Pep Boys, Firestone, Midas, etc.). Ask friends which mechanics they use.
In my opinion, it is too soon to replace the serpentine (drive belt in your post), as jtsanders noted, if not squealing or slipping, no need to replace. These belts last a lot longer than they did 20 years ago.
No drivability issues, throttle body is fine.

However, at that mileage, it is time for a transmission fluid change using fluid specified by Lexus. Likely time for a cooling system service again using coolant(antifreeze) specified by Lexus,


Have the other previous factory recommended factory services been performed on schedule?

If so, I might skip the throttle body if the engine starts and idles fine. As for the belt that can be a judgement call as a belt may deteriorate faster in one part of the country compared to another. Glazed but not cracked would not concern me as much so an inspection of the belt depends upon the expertise of the person who is inspecting it.
A mechanic is one thing: a fast lane lube guy is quite another.

It’s possible those services might be needed. No way to tell via the internet. $175 to clean the throttle body seems about right. $240 for a drive belt replacement could be ok too, if the service also replaces the tensioner and associated idler pulleys.

This sort of service is easily done & usually priced better at independent repair shops. Might be a good idea to ask friends, co-workers which shops they use, and ask around at those shops.

Belt tensioners don’t really get replaced as preventative maintenance, that is Cark Talk rumor.

The belt tensioner in mounted under the A/C compressor, a couple hours labor to replace.

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Since you work at a Mercedes service shop, this is what a Mercedes service website says about belt tensioners

You should expect to replace your belt tensioner in the 40,000-70,000 mile range. It is also customary to swap more than one part simultaneously, usually a worn-out pulley from other systems and even the serpentine belt itself.