GAMESHARQ

I have a 2014 RX 350 which I bought new. It has considerably low mileage. Recently, I noticed the engine is louder than I am accustomed to. It used to be whisper quiet, like you couldn't even tell it was running, but now it's a lot louder. I can hear it running when I am in the vehicle, and it's even louder when I am outside of the vehicle.

Also, it used to drive a lot smoother. Again, it used to be that when it was running, you couldn't even tell. Now, when I'm stopped at a red light, I can feel the vehicle shaking a little bit.

Is this normal for a Lexus vehicle that is a few years old? I'm wondering if I need some sort of tune-up.

I had routine maintenance done in January 2017 and they said everything was fine at the time.

salimshah

The key question is, was the change gradual and you just noticed it or you can say with good bit of authority that 1 week ago the problem was not there. Engine emission related problems throw out a code ,, like misfires

If under warranty, (or even without), make an appointment with service and if needed ask for side by side comparisons with their loaner or other RX.

Regrettably the noise and vibration have an acceptable range and each vehicle is different. But at least they can investigate your concern.

Salim

lawjaii

i have a 2014 as well, owned since new. i think i might have similar concerns as you. mine only 20k miles. just since early this year, i've noticied louder than before engine sound when idling.. and higher idling rpm when starting.. will talk to dealer before warranty ends this year.

MikeInOr

Are you guys using Premium 91 octane gas or regular 87 octane gas?

terryb111

I purchased 2013 RX 350, 30k miles on it, April 15. Now with 34k, the only noticeable added noise is the rear exhaust. But it sounds sporty, the same sound, when I purchased it. I filled up with Premium and the same sound for now.

Freds430

Would be unusual with your low mileage but valves could need adjusting if the noise sounds like a tapping.

GAMESHARQ

I took it to my Lexus dealer and had a mechanic look at it. I was with him while he looked at it. He said the noise I am hearing is the sound of the fuel injectors. He also said that the level of noise is typical of a 2014 model and that other owners have complained about how loud it is. The weird thing is that I don't recall it being that loud before, but he said it was normal, that I had nothing to worry about and there was nothing that could be done to change it. He did mention that newer models aren't as loud, though, and that they use different parts that are more quiet. It just irks me when I'm sitting in my car, especially when I am in park, and I can hear the loud noises coming from under the hood. It makes me feel like I'm driving some old, run down car or something.

In regards to the vibrating I sometimes feel when idle, he said it's the result of me not driving it as much as most people and since most of my driving is in the city as opposed to on the highway. For this, he suggested I take it out on the highway more often to help flush out the exhaust. He also said something about tires being "square" and trying to round themselves out again - I didn't really follow that part so I'm not entirely sure what he was referring to. I guess I'll have to take it on the highway more often to see if it helps.

GAMESHARQ

I use regular. Should I be using premium? Would that help based on what the mechanic told me (see previous post)? He didn't mention anything about the gas I should be using.

Clutchless

You could try running a bottle of Techron Fuel System Cleaner in the gas tank as it will clean up the fuel injectors as you drive and may make them quieter. At under $20 for a large size bottle, and it is often on sale 2 for 1 at Advance Auto etc, it is an inexpensive investment to do a couple of times a year. It will also help remove carbon build up from the intake valves which contributes to a rougher engine as the miles accumulate. .

GAMESHARQ

Thanks for the tip. Is this what you are referring to?
http://www.autozone.com/fuel-and-eng...aner/27796_0_0

I may give it a shot to see if it helps.

MikeInOr

I believe the 2014 RX-350 calls for premium??? If it does call for premium it will probably run a bit smoother on premium. If it calls for regular switching to premium will probably have little affect. A indirect injection engine adjusts for different fuel octanes by adjusting the timimg. You might need more than one tank of premiun (If the engine calls for premium) to allow the engine timing to completely adjust. Usually switching from Premium to unleaded is where you will notice the change in gasoline grades as the engine will start pinging until the computer adjusts the timing.

Premium / regular will make absolutely no difference on injector noise. I really doubt that the RX-350 has injectors that are much noisier than any other 2014 car... I bet the rest of the engine is so smooth and the car is so quiet that the injector noise is noticable where the injector noise is covered up by other engine noises in most cars. Fuel pressures have been going up to help increase efficiency. Higher pressure injectors could be noisier than older lower pressure injectors. Bosch is the major fuel injector manufacture. I would not be surprised it they found a way to muffle the sounds their injectors make when the injector opens and closes.

I doubt fuel injector cleaner will make any change to the sound the injectors make when they open/close. But if you TRUELY BELIEVE injector cleaner will make a difference you can probably fool yourself into thinking it made a difference.

It is conceivable that that the injectors got a little louder as the engine / injectors were broken in. Probably not really, but if it lets you sleep better at night we can run with this theory.

jfelbab

My 2014 RX350 calls for regular fuel, FWIW. I don't have many miles on mine either, 21,000. It is still very silent apart from tire noise. My tires are worn to 6/32nds and were always relatively noisy. They are Dunlop Grandtrek A/S. I hate these tires and might replace them soon. Engine is whisper quiet and smooth running.

My vehicle does get noticeably noisier when the AC compressor is running.

Clutchless

Gamesharq - that is the right product. Get the largest bottle available as it comes in 2 sizes. Also Redline fuel system cleaner will work just as well.