I noticed a "knocking" sound coming from the engine of my is350..it happens when the car is in idle , could that be the fuel injectors? I know that the is350 has a twin injection system called D-4s,I can hear it from the inside of the car. Another question I have is that when I turn off the car and open my door I hear this "motorized" sound,like when you would close or open your windows, I know its not the door locks opening because the sound is coming from the instrument panel.it started after installing lojack.

 

The knocking is the fuel injectors, because the is350 uses direct high pressured fuel injectors. Sorry i dont know about the other problem.

 

What kind of fuel are you using?

 

The motorized sound you're speaking of is actually from the evaporative system purging and stabilizing the vapor from the fuel system. You will hear the same noise after the car sits for over a few hours or over night also. Credit for that finding goes to VVT-i. Take a look at this thread for more info:

https://www.clublexus.com/forums/sho...d.php?t=160829

 

I hear all these little noises from my car, too.

 

Had a chat with the Senior Service guy at my dealership yesterday about engine 'ticking'. He confirms it is the fuel injector pintels (sp?) closing. Had a similar problem on the RX and Lexus developed a new pintel that was quieter. No word if Lexus will try to improve the IS engine pintels.

He also commented that the ticking comes and goes as a function of outside air temperature and engine temp. I have observed this on my IS 250.

I have only noticed the noise when I'm outside the car or along side a drive-thru with the driver's window down.

 

I use premium gas on the car.Ok if it is the evaporative system how often should it happen? I hear this buzzing sound everytime I turn off the car and open the doors.Could it be the cold weather? about the injectors I am dissapointed that they make too much noise, shouldn't a Lexus be quite and smooth?

 

Yep, it happens every time.

 

...about the engine ticking. i thought that i'd read some time ago it was the injectors, but glad to hear that im not the only one! its only at idle and i cant hear it with the windows closed - really noticed it at the drivethru at taco bell .

 

stop going to taco bell then.