So ever since I got my 2015 RC350 I found the motor noisy, after searching around it seems common for the DI motors. I assumed it was okay but lately it seems a little louder and then a friend of a friend showed up in a 2015 RC350 and her motor although a bit noisy is magnitudes quieter than mine. I'm due for a maintenance visit anyway and the car is covered under CPO but was curious if there are any known issues that cause such the motors to be so loud? Faulty injectors, valves sticking, etc....?

 

For used models, it can often be PPE headers install without informing you during the selling process.
Do you bought this car new ?

 

CPO from the dealer, I haven't see any aftermarket parts on the car. Have an appointment next week for maintenance anyway so I'll have them look it over.

 

Just a thought...
1. When you compared the sound on both motors on the RC's, were they both warmed up equally?
2. Pop the hood, is the engine cover present?
3. Remove the engine cover and inspect the underside. Is the foam intact, damaged or missing?

 

Both cars fully warmed up, both cars have engine cover present, didnt check under mine but the sound is more motor than injector in my opinion. I'll check to see if its foam is intact.