I just bought a RX 350 from a Lexus dealer in Houston, with 70000 miles. I heard this engine noise and asked them to address it. They said it was normal, which I know it is not. I have a 30 day/1000mile warranty. Any thoughts what this might be? It is intermittent. Tks.

Edit: Ok, when I turn off the AC it goes away. Compressor clutch?

 

Test out another RX at the dealer lot side by side.

Also why would you insist on buying something that you suspect is bad from day1.

Salim

 

I would assume the noise is from an bad AC compressor clutch bearing.

Replacing an AC compressor clutch is not an hard repair, even DIY. However, it maybe cheaper to buy an new aftermarket compressor as opposed to buying just an OEM replacement clutch assembly.

I personally would just try to replace the clutch(aftermarket or OEM) on my RX350 if it goes bad, unless I have to remove the compressor from the car to change the clutch assembly then I would just go with an new aftermarket Denso one. Many times the AC clutch can be changed without removing the compressor from the car or opening the AC system.

 

Get an independent used-car inspection with written results. Tell them of your concerns about the air conditioning. If it is found to be bad, take it back to the dealer and demand repair or your money back.
You have a 30-day warranty.