GBW

I've been chasing some "boost" issues, and making some progress with help from the forum. What I thought was a boost issue, turned out to be a failing coil pack and the ECU retarding the timing. Thanks to ModifiedA4 and others for a boat load of assistance on that.

My one remaining issue is a "hiss" I hear under acceleration from about 3,200 rpm and up....it's quite noticeable at 4,500rpm. I suspect it's a vacuum leak. The car has no codes and run flawlessly. Boost seems excellent and I've done a pressure test.

Thus far I've done a visual check of the vacuum hoses and the PVC system, and there is nothing visible. I've also sprayed the hoses with startling fluid without finding anything.

I could use a EKTA diagram of the PVC system for the ATW engine....the ones posted here are for different codes.

I have found something on the firewall that does hiss (engine is not running) when I was playing with the Suction Jet Pump. The item circled will "hiss" when it is twisted slightly. I believe it is the check valve for the brake booster. It appears to be a snap fit; no clamp. Is it normal to leak if this gets twisted?

Lastly, while everything looks good, something's not, and the dates on the check valves are '00....so I'm assuming it's original. Should I just replace everything as a maintenance item assuming that will also fix the "hiss"

Any comments or ideas would be appreciated.
<a href="http://s152.photobucket.com/albums/s189/GBW_Audi/?action=view¤t=IMG_1441.jpg" target="_blank"><img src="http://i152.photobucket.com/albums/s189/GBW_Audi/IMG_1441.jpg" border="0" alt="Photobucket"></a>

kgardnez

It's normal to leak when twisted as you side load the seal

4Driver4

Your belief is correct. Condition is normal.

TristanP

How old is your L hose?

GBW

It no longer has the factory squeeze clamps, but screw clamps. Everything else still has the factory squeeze clamps.

Purchased the car late last summer, so I don't know when it was last replaced. Soaked it with starter fluid...nothing.

Silver Streakin'

normal