mechanical failure: brake booster code

[old guy]

I apologize if I repeat anything already covered in this thread but to be honest I haven't been following it and I am too lazy to go back through two pages of posts. Now on to your problem: What year? Makes a difference in the block breather set up. If you clamp off that line and your idle improves that is a pretty good indication that either your PCV valve needs replacing or you have a vacuum leak somewhere along that line.

[pimp'n]

2003 B6 1.8t. I have a haynes (sp?) diagram of the system but it's crap to be honest. Where does that line go from and to (aside from the obvious manifold entry)? it appears to connect to the crank case breather tube underneath the manifold and then head to the SAI valve but I'm not completely sure. might be worth just replacing all of it?

[old guy]

2003 B6 1.8t. Where does that line go from and to (aside from the obvious manifold entry)? it appears to connect to the crank case breather tube underneath the manifold and then head to the SAI valve but I'm not completely sure.

On the 2002 and early 2003 the PCV valve connected to the block breather and then routed through the SJP and ultimately to the intake manifold. It utilized this PCV valve: Clicky click. Since you mentioned that you have a 2003 with two separate lines from the manifold I have to assume that you have a late 2003. Because of the sludge issue Audi added the second vent line and started using this PCV: Clicky click The side port connected to the small vent line that was added to the valve cover to provide additional block breathing to reduce the likelihood of sludge formation. Instead of routing the vacuum line through the SJP an additional port was added to the intake manifold and the vacuum source was connected directly to the intake manifold (that would be the second line that you referred to). The SJP gained a fresh air source from the TIP on the other side of the block.

If you pinch off the vacuum line supplying the vacuum to the PCV and the idle settles down that would be an indication that the PCV is allowing excessive air into the intake manifold indicating one of two things. Either the metering portion of the PCV valve is messed up and allowing excessive air to flow through into the intake manifold or the PRV on the back of the valve cover is defective and isn't metering the air into the block properly. I would start with the PCV valve since it is considerably cheaper.

[pimp'n]

hauled he lines out and pulled everything apart and it turns out the PCV had failed. the seal was sideways inside the housing? anyway, replaced it and that seems to have removed the misfire issue. hopefully it addresses the other codes in time as well. I'll check back in a bit and let you know. Thanx again for everyone's input!

[old guy]

Glad to hear you finally got it sorted out (fingers crossed).

[pimp'n]

k.... cleared codes and none have come back so far. HOWEVER i still can't get the car through the MOTHERLESS @#$%!*&^%#$@! at Aircare as my readiness codes show 0000 1000 secondary air injection incomplete or fail. I've gone through a "drive cycle" or two 100km down to 50km cruise no brakes etc etc etc and still no luck getting rid of that one. Any ideas? as i say, no fault codes coming up. Thank-you.

[daverdfw]

i had a similar issue where it took like a seek for the SAI readiness to become ready, not sure why it took that long,

[old guy]

k.... cleared codes and none have come back so far. HOWEVER i still can't get the car through the MOTHERLESS @#$%!*&^%#$@! at Aircare as my readiness codes show 0000 1000 secondary air injection incomplete or fail. I've gone through a "drive cycle" or two 100km down to 50km cruise no brakes etc etc etc and still no luck getting rid of that one. Any ideas? as i say, no fault codes coming up. Thank-you.

Have you gone through several complete cold to hot to cold cycles? The SAI system isn't going to activate on a warm start and it probably will not reset until it has succesfully completed the required cycles.

[pimp'n]

two or three in the last 24 hrs at least. question is what constitutes cold to hot? I've done some "drive, park the car for an hour or so and start again" type stuff plus one over night park and start.

[old guy]

two or three in the last 24 hrs at least. question is what constitutes cold to hot? I've done some "drive, park the car for an hour or so and start again" type stuff plus one over night park and start.

The block has to cool down completely. Parking the car for an hour or so will not suffice since there will be plenty of residual heat to keep the SAI from kicking in.

[pimp'n]

this seems to have done the trick. No codes popping up and all readiness codes read 0. Fingers crossed but i think this may have cleared everything up. Thanx again to all for your input! it's greatly appreciated.

[AlyAudi03]

I think your numbers are too high. I believe the servo vacuum pump should kick in once you hit about 650mbar.

Not sure if it means your brake booster diaphragm is leaking or your servo pump isn't working properly.

Should it kick on when the car is off? He didn't have the car started at the 960, when he started the car it dropped down to 580. Does it matter if the ignition is on the "on" position if the servo pump kicks on or not? I'm just asking because i did the test. field 3 rested on 425, field system ok. However, Prior to activating the test on my car, it went up close to 900 but I have no idea what the number actually was because it was dropping rapidly. Did I even do the test right?

This is kinda confusing: ; Firmly press Brake Pedal twice > Field 4 = Test ON
I put my car in neutral, activated basic settings, pumped brake pedal firmly twice, (activated showed up in field one), I pressed the "test on" button at the top next to basic settings, field 3 dropped to 425mbar and field 4 said system ok. Does that sound right or did I do something wrong.