Earlier, I asked about a "tone" that I heard when pressing the gas pedal. Several suggested it was a noisy electric vacuum pump, but I didn't believe it because it was happening when I pressed on the gas, not the brake.

It's getting louder and I was in a drive-through last night (White Castle employees are top Bentley fans, apparently) and with the window down and a wall right next to the left of the car, it's pretty noisy.

My shop told me they ran the diagnostic on the system and although the pump was noisy, it was making correct vacuum.

So here is my question: the noise makes me crazy. I hate it, and if it takes changing out a $400 part, I'll do it. But still the same question persists: why would it be noisy when I press the gas, not when I press the brakes? Has anyone changed an electric pump, does it quiet things down?

 

Hello British,

Too much bad advice here about vacuum pumps and vacuum leaks!

But to stay with you here, can you describe the noise a little better/ Does it change tone with RPM?

White Castle (I'm embarrassed to say) is one of my favorites. We are gettour our first WC here in Scottsdale, scheduled to open this month...and with half the Midwest retiring here, right at home!

 

Forgot to add. If it is the vacuum pump (or if yours is noisy anyway), yes, I have changed them and don't get suckered into the $400 Bentley one when the much less VW one is the same pump.

 

Any chance you have the VW part number? I wish we had a broad cross-reference.

Here is something pretty close to the tone. It goes off after I've been driving for a while, it is audible when the car isn't moving. It goes off when my foot is on the brake and then starts up when my foot hits the gas. It does not get louder with speed.

Again, it goes on when I press the gas pedal, the brake does not seem to affect it at all. Sometimes it will simply sound at idle too.

 

I know this may be a pain to do, but is there anyway you can make a video, post it to Youtube and link it here? I would like to actually hear the sound so that if others have this problem, there would be no question on how to remedy it.
Listening to the tone generator you posted, it reminds me of metal and use something to gently touch the rim of it to make a calming sound, if that makes sense. Like if something with bearings in it not lube good. Or a pulley. It is a good chance I am wrong lol, but I am going off of some of the sounds I hear at work when we have to drop out a shaft or bearing housing because the motor on the line sized up.

Is this the part number you are coming up with for the Bentley pump? 8E0927317J.

 

I tried that, the noise isn't loud enough to be picked up on my iPhone microphone. Although it's getting louder, my daughter this morning said, "That sound is really obnoxious" as we were in the school drop-off line. You can't really hear it when the car is moving from the road noise, but when it is at a stop light, pressing the gas makes it go off.

It isn't mechanical or suspension-related, it's not related to the car moving.

It happens when I press the gas pedal, as if a sensor goes off. It could possibly be coming through the sound system (although it pre-dated my new radio). It's a "tone" and is not localized.

How do I test the vacuum pump?

Why would the vacuum pump start up when I pressed the gas pedal?

 

Hey British

Here is the P/N



Sorry for the rotate. This is the box from the last one I replaced. These pumps are all the same number. Just google the part#. Plenty of the VW ones online. I purchased this one for a VW but went into a Bentley. Also, don't worry about the alpha suffix. This one is a 317A, could be any letter and all are the same. Just buy what's least expensive and DO NOT buy a used one! Plenty of those too on Ebay.

 

Also, if this, in fact, is the vacuum pump making the noise, replacing it with new will make it quieter, but it is not the fix to this problem.

 

I'm wondering if my sound system is picking up the motor noise.

 

Sounds in these cars can make us think we're hearing things. That is why I and TJ are asking more clarity about the sound. I don't want to "Ready, Fire, Aim" at your problem. Some here do that, but not helpful.

On the noise, I remember recently the thread from our dear member in Vietnam. The auto door lock clicking on takeoff made it sound like a rear end clunk. Go back and look at all the advice given before the sound was more explored.

Not meaning to impugn anyone's character here, just trying to leave good technical info for posterity's sake.

 

I had a post talking about this but erased it. So I’ll go into it a little now. IF it is from the audio, it’s a weak ground somewhere. It’s called a ground loop. It is a whining noise that sometimes but not all the time goes with acceleration. Other times it can be just a really light whine. Some people call it alternator whine. I have it in the slightest way at no volume but I chalk it up to being the Ben HUR. They make a thing called a ground loop isolator that helps sometimes. Some cars just can’t be help when putting in aftermarket anything...radio or amp. I know you had yours done at that one shop, and they seem to know what they are doing (just their prices are overwhelming) I wonder where did they grab your ground from. Also I’m not a fan of crimping wires together as I solder everything I do to make my connection as tight as possible.

Try this. Have the princess(your daughter) sit in the drivers seat and slightly give it gas to the point you can hear it. Turn your radio to 0 or 1. Go to each speaker and place your eat right on it...even the sub and see if you hear it. Have her let up and apply a few times. Then turn the radio completely off. See what you get.

I just ran out to my Escalade to try to capture the sound I have. Only thing I did was put in a Alpine head unit with a iDatalink Maestro and I have a slight whine.

https://www.dropbox.com/s/mk5bw5ardz...noise.m4a?dl=0

 

British ... It sounds like the system & it comes down to the Ben-Hur ask the guys who fitted it did they connect a ground loop isolator between the Ben-Hur RCA's & the Alpine RCA's if not then theres your problem, then it could be how the RCA for the sub was taken from the head unit to the boot, The Ben-Hur must be isolated I got this info first hand from the engineer at Ben-Hur ...

 

I'm really familiar with alternator whine, this isn't that. Alternator whine is very distinctive and changes in frequency with engine RPM. I tried to get an audio of it today, but it just doesn't come out on the recording.

Also, this sound came before the Ben Hur installation, so if there is a problem, it's in the power amp.

Thanks for the recording of your sound; it isn't mine, mine is a tone and I'm beginning to think it is from the electric vacuum pump going bad, perhaps this is causing enough EMF to get picked up by the audio.

I'm going to try your experiment and put my ear to the speaker(s) to see if it's amplified

Thanks guys.

 

No problem British. That’s what we’re here for. Hopefully if anyone else has your issue they can sort it out quickly due to your thread.

Going back to your older post on here, you said you could really hear it when you were at WC next to the wall. You think you can find some place around like a empty parking lot next to a building so it can be amplified some like at WC? Have you notice how does the sound act once you turn the car off? Does it go away ASAP or does it slowly attenuate? (At this point I’m asking for myself just in case I experience this)

 

Welcome ...