high pitch electronic sound

[FVWVWF]

Im no expert on diesel engines but my previous diesel (a pick up) didnt have this. Can anyone tell me what exactly is this high pitch sound that you can hear when outside of the car but not inside?
Its not a whining or windy noise...just sounds like something electronic under the hood is making it.

And how loud is normal? If someone with sensitive ears would stand next to the car, they'd end up going crazy.

Thanks.

 

[JettersTDI]

I think it's your glow plug...I'm not sure, but I hear it also.

 

[JettersTDI]

Also, if you put the ignition to ” ON” position you will hear the same noise. I think it's normal.

 

[TDI_Timmy]

I'll go with the electric fuel pump(s).

(This does not include the HPFP)

 

[FVWVWF]

I'll go with the electric fuel pump(s).

(This does not include the HPFP)

I just checked my VIN on the website again and found out there is a recall on my car for fuel injection lines. I'll get that done right away.

Is the sound normal with everything in good working condition?
Want to prepare myself when I pick up the car and the sound is still there.

 

[TDI_Timmy]

I doubt you can hear the injector lines.

The lines would be different from the pump(s).

Do indeed get the recall fixed, but I bet the sound would still be there

There is so much electronic emission things/analog emission things on these cars that it makes noises that we might not be used to.


It also could be that when you were listening you heard the radiator fans spinning full blast because the car was going through an active regen of the DPF.

But, when you say whirring, I am thinking very high pitched, similar to that of an electric motor.

(just my very random thoughts at 3am. )

 

[philip_g]

our 11 does it too, it's definitely under the hood and you can hear it for a few seconds after the car is shut off. Just a high pitch EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

 

[andy7079]

High pitched noises are caused by high frequency drives on valve motors. There are several on the emissions system. When turning the car off, the exhaust system does an adaptation where exercises the valves.

Other sources of high frequency noises are the fuel pumps.

 

[740GLE]

Agreed, VW ECU uses PWM signals control how much a valve is open. There are quite a few of these valves in the car, intake, exhaust and I'm sure a few others.

The EEEE sounds you hear is the switching frequency of the PWM signal, my guess is probably around 1K-2KhZ or so. If VW chose anything above 15Khz you'd prob wouldn't hear it (many adults older than 30 loose the higher frequencies first).

 

[FVWVWF]

Thanks guys.
The sound does sound normal, I was just wondering what it was as working in the transportation industry and being around trucks all the time, have never heard that before. (not to that extent anyways)

 

[jettahighline]

I heard the same problem on a 2008 Passat 2.0T. They say its the respirator valve or some sort of valve.. not sure if it's going to be the same on the TDI...

 

[joris]

haha this just happened to me. 2012 golf. I love this forum.

 

[Sergeant TDI]

I hear this too, but only sometimes. It's not that loud though. If you are playing the radio, you can't hear it.

 

[pleopard]

It's not something that "happens". It's perfectly normal and is always on when the car is on and for a few seconds after shut down immediately prior to the adaptation.

 

[gweigwei]

High Pitched TDI sound - is the diesel engine

It is the diesel engine sound. My sales person said it's normal. I have just purchased Passat TDI 2012 two weeks ago and I asked my sales person the EEEEEEEEE sound.

our 11 does it too, it's definitely under the hood and you can hear it for a few seconds after the car is shut off. Just a high pitch EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

 

[TDI_Timmy]

It is the diesel engine sound. My sales person said it's normal. I have just purchased Passat TDI 2012 two weeks ago and I asked my sales person the EEEEEEEEE sound.

First of all, welcome to TDI club. I might be perpetuating this, but I am just curious as to why dig up a thread nearly 6 months old from last post to add on something that was for the most part settled. Now, if it was a question that pertained to this topic then I would thank you for searching, adding a question to an existing thread instead of starting an entirely new thread.

Also, it isn't the diesel engine sound - diesel engines rattle not go EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE unless there might be a rodent or a cat stuck in the serpentine belt.

It is is what Andy7079 said a few posts earlier.

High pitched noises are caused by high frequency drives on valve motors. There are several on the emissions system. When turning the car off, the exhaust system does an adaptation where exercises the valves.

Other sources of high frequency noises are the fuel pumps.

 

[TDIadvocate]

High pitch whine

They all do it, I have a 2012 TDI, 16,000 miles, been doing it since I bought in September 2011. Dealer says normal (but if the engine fell out he would say that is normal also, little humor). While they avoided giving me a direct answer I think it is the pressure in the fuel line draining down, it goes away in less than a minute when I turn car off. I don't hear it while driving.