2005 Bentley GT. About 60k miles on it. I'm the second owner, bought it a year old. It's been a great car these past 15 years! I've love every minute driving it.
Has not given me any trouble over the years, so I can't complain. The past 2-3 years, I've been hearing a weird "buzzing" sound when I start the car coming from the drivers side wheel well.
I bring it to my local car guy and during an oil change, I pointed out the noise to him and he thought it was the air suspension. (He thought it was leaking and the buzzing was the compressor compensating)

He tried running diagnostics with his machine, but couldn't get all the codes. He recommended I bring it to Bentley for a true diagnostic.
A few days later I woke up to the dreaded "lean". The passenger's side was sunken all the way down to the wheel. When I start the car, it would inflate and drive/stay that way until I turned the car off.
It would then take about 30 minutes for it to fully deflate once the car was turned off.

After consideration and posting on here, I decided to remove the air suspension and replace with with Strutmaster coils as I didn't want to invest any more money than necessary into a 17 year old car.
I'm happy with the coils, the only issue is the annoying warning lights on the dash, but something I can live with.

It's great now, but the same buzzing sound I've been hearing for the past 2-3 years is still happening! Turns out it's the vacuum pump. Whenever I hit the breaks, the vacuum pump comes on for 21 seconds, then turns off.
No warning lights on the dash about this, the car drives great, has great power, no complaints except that buzzing sound when I hit the breaks.

I realize there is most likely a leak in the vacuum lines somewhere, I think...I don't think it's that bad as it's been like this for 2-3 years.
I don't really want to drop the engine and replace the lines as the car is probably worth $20k in the condition it's in. (I drive it like it's meant to be driven, fast and hard.)
Couple of questions
1. Can the vacuum pump be bad, and replacing it fix the issue?
2. If there is a leak in the vacuum line, and I replace the pump, would a newer pump be more quiet?
3. What happens if I just leave it the way it is? How important is the vacuum lines on this car? What would happen if I just let it be?

A new vacuum pump installed would probably be $1k, which would be fine. Whereas dropping the engine and replacing the lines would be $5-$6k and not worth it.
So I plan on driving it until it doesn't drive any more and getting a new car. But would love to hear your feedback.

I'm not taking long road trips, just local driving.

 

I had a noisy vacuum pump in my 2007 Bentley GT when I bought it, in 2017. It took me a while to figure out what it was.
I bought a new one for about $400 on E-bay. It is the same as the one used on an Audi A8.
Changing i was easy, though it took a bit of doing to jack up the car and get a stand under it.
It still runs, but at least now you can barely hear it.
Bob

 

That's a classic symptom of a vacuum line leak. And if so, that's more like an $8k procedure to do. Good news is that you'll get more at resale because people will pay more for a car that's had this work done. Of course it could also be just a bad pump, or could be a leak in one of the lines that was plugged when the air suspension was removed. There's no CEL on the dash? That's prob a good sign.

Can't say the same for your decision on the struts. I think you may have unfortunately eliminated any resale value the car has. I'd never buy a car where the prior owner changed the design of the suspension, especially where the work was done to save money.

 

I like this idea, most likely going to get this done. Thank you!

 

Thank you Samhain. I have no intention on selling it, I plan on driving it until it doesn't drive any longer.
The car was worth about $20k in the condition it was in. It wasn't worth replacing the air suspension for $10K+, nor is it worth spending $8k on new lines.
I'd rather put that money towards a new one.

Was just looking to extend it's life for another year or two as I'm in no rush to buy a new one.

 

You have a vacuum leak. Changing the pump might make it quieter but it won't solve it.

I had the same symptom, no CEL. And I had quite a large leak when I smoke tested it. When I fixed the leak, the brake pedal feel was much better, the turbos snapped on, revs dropped, it was transformative.

Being a 2005, you are facing an engine out job potentially to fix. But, I would get it smoke tested first. There's always the possibility that the leak is somewhere accessible that you could fix for cheap.

 

Thank you, going to take it in for a smoke test! I appreciate the info!

 

Good luck - hope it's something simple.

 

Thank you, me too!

 

I have another post here on this subject. My car has a leak in the T's and is going for an engine out. BUT, I also had a broken solenoid on the top of the engine. Take off the close out panel on the front of the engine and take a look at the solenoid and the rubber lines.. My vacuum pump did the same thing until I found this valve broken on both legs. Replace it myself with a $16 BAPMIC valve off of Amazon and it fixed the problem. Still have other leaks but not the brake problem. I have pix on my post. Good luck.

 

Good to know, thank you!

 

This is exactly my issue too.. Press brake, pump activates for 22 seconds, just as described. Fortunately, I don't have any other issues like rough idle etc. I do have a small suspension leak where the front will drop after a week, but i don't think it's related.

For a $16 possible fix it's certainly worth a try. Do you happen to have the part number off the original part? The part I think you're referring to has an Audi logo on mine.

Thanks!

 

Here is the part number and description from the cheap part I bought on Amazon

Bapmic 037906283C EGR Vacuum Solenoid Valve for Audi A3 A4 Volkswagen Eos Jetta Passat

This is the 'good' Pierburg/OEM valve on EBay @$36
Pierburg OEM Air Intake Control Purge Valve 7.22880.01.0 for Audi VW Porsche

I believe Bapmic part number is what you will find if you search the Bentlley IETIS/IPC or Scuderia or Flying Spares. I believe it is used in several places on the car. Variously it is the turbo boost control solenoid, waste gate solenoid, purge valve yada yada. All in all a rather inexpensive part that is usually hidden deep where you have to play hell or drop the engine to replace it.

 

I like the fact that you "drive it like you stole it"! That is awesome having a Bentley as a daily driver. Mine is unfortunately more of a garage queen, and I wish it was different.

The only positive thing for me is that I believe the curve finally may have changed for these older Bentleys in great condition, so I should at least be able to get my money back. That is, if I ever sell it, and if the worldwide economy gets out of the ****ter.... heh

 

I had the annoying vacuum noise, but no leak, it just had an irritating noise whenever it ran. The interior is so quiet, it felt amplified, since it's bolted to the car.

I had them replace it. Sound got better, but not by much.

I think it needs some dampner between the pump and whatever it's bolted to, having already thrown $600 at it, I don't feel the hurry to do anything more. I was thinking it was wearing out, and I didn't want a failure, so I was driven to replace it, I know that pump works really hard on this car.

Anyway, this might just be a 2005 model irritant that doesn't exist in later years. Replacing the pump, for me anyway, didn't really solve the problem.