As all modern cars having more complicated vacuum systems and computers. Finding error codes becomes more difficult. Especially, when finding to find vacuum leaks. This is how I do it on all my cars and just wanting to share

First off, you need to know how to test your vehicle. In some cases, you may be able to hear the vacuum leak. Other cases you spray something flammable where you think the leak is and the engine runs better (Don't) and before you burn your hair off, you may found the leak. These methods are not good and there are much better ways to locate vacuum leaks. Let me explain.....
1. Smoke testing: This is a method where you insert smoke into the vacuum system of your car. Some people just inject something like cigar smoke or something. I would recommend a professional smoker. They don't have to cost a lot and always very useful. This is the one I use below:



To successfully smoke test a Bentley, you need first to remove the intake filters and plug them. It is important the smoke will not escape there. To plug the intakes, I use airbag adapters like below:



Here is what it looks like in the Bentley while inserted into the intakes:

Of course, you could also use tennis ***** to plug them
Next step is to know, where to introduce the smoke into. Below is a picture showing where the smoke machine ins connecting into. The location is inside the left wheel well where the vacuum pump reservoir is :



Just plug the tester into the location I pointing to and turn the machine on:




Make sure,you not pumping in too much smoke pressure or you may blow up your vacuum system. As your tester in injecting smoke into your car, you will easily see if there is a leak somewhere and can locate it.

Method 2:

Use a ultrasonic locator.
This is a great tool for AC/Vacuum/Tires, and much more, where you can actually listen and locate any type of leaks. I would say this is one of my favorite tools I own. I am using this one:



It is not a cheap tool, but so many times I have had great use of it. For example, I had wind noise in my car while driving 65MPH+ and was never able to locate the whining sound from the leak. This tool easily found a leaking door seal and I was able to fix it. This also works for residential issues, such as HVAC and much more. It is a well worth investment. There are several vendors out there, but knowing what to have in your toolbox is important. To locate vacuum leaks just move it across your engine and you will easily hear an intensified sound from the vacuum leak.

I hope this helps,

~ZaOs~

 

That ultrasonic detector is a great tool. I have a stethoscope that I have use since the 70s and it works pretty good.

 

LoL, yes, agree. I used one too in the past. If you have the money, this is on steroids...LoL