Bokx_350

I have recently noticed that engine idle sound of my car is kind of weird. I think it is louder and "choppier" than it should be. It sounds like if there were a helicopter flying around. I popped the hood to see if I could tell where the sound was coming from, but the sound is unnoticeable from outside the car.

I can’t remember if it sounded like this from the beginning since I always drive with relatively loud music on.

I would really appreciate if another C350 owner could share what his idle engine sounds like. Is it loud and choppy? Is it so quiet that you have to look at the revs to see if the car is on?. Thanks in advance.


P.S. just anticipating a question: By idle I mean the car is completely stopped, regardless of the gear (it sounds the same in P,D or R)

ATSOBE

I too drive a c350 it sound like you mention . But i heard also two differnet new mercedes all their engine sound like that too. Their all choppy i guess it just the mercedes engines that i think sound like this i guess it casue they have soo much power and torque. Or they have a much more open exhaust for more power. Dont worry mine is 7 days old sound like that too.

qwerty1024

Just recently there was another thread where the poster was asking about the 500 RPM idle speed, and the fact that at idle the engine sounded a certain way (I don't recall how the poster described it).

Anyways, I did notice that the engine isn't as quiet as, for example, just for the sake of an example, my wife's Honda Pilot V6 3500cc. That engine is unusually quiet at idle and very smooth running.

I have very little automotive knowledge, so the best way I can describe the C350's engine is that, at idle, it sounds more "mechanical", noisier, but not at all in a bad way. There is also absolutely no variation in the idle speed: it is chiseled at the 500 RPM mark.

I'm curious what other engine you might be comparing the idle sound of the C350 with. Thanks.

RLE

<<I have recently noticed that engine idle sound of my car is kind of.......

My C300 (400 miles today) makes the sound at idle you are trying to describe and I think it's the emission system air pump. I am going to inquire at the dealer.

Probably, annoying as it is, normal.

imboom

Anyone notice also on ignition the car sounds like its winding up something with resistance? I can't explain it in words but it kinda shocked me at first.

Bokx_350

Comparing the sound of the C350 with other cars (on idle) I can say that my Infiniti Fx45 has a much deeper and aggressive sound, but without the chops; it is a steady sound, and a more pleasant one. My brother’s Audi a4 1.8t was very quiet when new; you could barely notice the car was running.

My main concern is the chops, which are usually a sign of a bad belt or bad pulley; or a fan that’s about to die on you. Even though I know this is not the case; I'm still annoyed by the sound.

After reading the replies, I’m glad to know that this sound is “normal” and that my car has no problems. However, it is somewhat bad news at the same time knowing that we are stuck with this sound. I just hope I learn to like with time.

JimPap

Bokx

Try turning your air conditioning off to see if it can be compressor related.

As to interior sounds, I found that if I adjust all air vents to "full on", there is less air noise flowing through the system. On the way back from picking up the car when I first purchased it, my passenger had reduced the air flow on a couple of vents. I discover this 3 weeks later and when I opened them to full on, the car got much quieter.

Bokx_350

Thanks for the info.
I'm sure its not the A/C because i've been driving with my A/C off (its getting kind of chilly here in the Boston area). I check it out tough.