View Full Version : Vacuum leak - vacuum jet? Help please

10-21-2016, 08:37 AM
So I just finished replacing my main vacuum lines this morning, and I fired up the A4, and I read -10 hg for vacuum. I know normaly our cars idle between -19, and -20, I heard a leak for the past couple of days, but wasn't bad until yesterday. The issue with low boost was the quality of the vacuum lines I used. I re replaced them with standard vacuum hose, and she is running about -16, -16.5 with the lights off.

10-21-2016, 08:19 PM
Update: I replaced the vacuum pump thing, and I used silicon hi temp on the rubber piece near the base. Boost leak tester picks up FPR to IM (I have tried two different lines, and two hose clamps..)

Also, gonna laugh.. My turbo is leaking coolant on the cold side, at the return line. I thought it was the actual hose, so I replaced that, and still dripping coolant/steaming it off. I don't really know where to go from here. I've done basically all I can think of. Still hissing by that jet pump, only when the engine is running.

-11 vacuum. -9 on cold start

10-21-2016, 08:32 PM
Spray brake clean around. The vacuum will suck it up and the engine will idle slightly higher. Ether works too

10-21-2016, 08:44 PM
Just wherever there may be a vacuum leak? I tried soap and water which helped a little, but I can't seal the FPR. like the line is perfect, clamp is as good as I can get it and it still leaks.

10-21-2016, 08:54 PM
You should be able to hear a leak like that. Put your finger where you suspect it and you can feel it suck

10-21-2016, 09:00 PM
That's the thing though, I can feel the IM-FPR line leaking slightly at the fpr side. The issue is that no matter what I do, I can't get it to seal. I've adjusted the line and clamps and she doesn't want to seat.

On top of that, I don't want to keep running the car until I figure out my coolant issue. I probably am going to have to replace that hard tube with the copper fitting. This has turned into quite the project.. Lol

10-24-2016, 07:24 AM
Still hear air from the same area. Yes, I did position the arrows towards the motor, and connected all three hoses to it. I'm lost. I tried brake cleaner all up and down the connections, and no rpm increase, nor can I feel air anywhere.

Edit: 2001 AWM GIAC X spike 11 psi, holding 10 psi to 5000 rpm. I have done a boost leak test, and I don't hear any boost leaks.

10-27-2016, 10:24 AM
I can hear air leaking still, and air escaping for a brief second after shutting off the engine, coming from the brake booster area/under the manifold. I have tried carb cleaner over all of the connections that I see, and nothing raised the engine rpm, where should I go from here?

10-29-2016, 07:33 AM
With the intake at the manifold off, pressurise the manifold at 20 PSI. You should hear that hissing sound, then use soapy water. The leak will be toward the outside, and the soapy water will create bubbles around the leak.