Change in vac pressures??

[GeeJayzS4tyme!]

Am I looking for a boost leak???

When I 1st got this car (in August) I had vac pressure ~ -22inHg and it would vary depending on whether it was off-throttle or idle. (I was used to the same reading and situation w/ my 20th).

NOW it's a steady -12inHg. No varying from off-throttle or idle. Car has a Samco Y installed.

I'm NOT losing boost. Can still summon up 19 psi spike (GIAC chip), and it pulls fine. Or is this just weather related or something else?

TIA

[AudiSportB5S4]

12 in Hg is a leak. When you have 12, is that with or without the heat/ac on? is the clutch in? What does it go to when you have clutch engaged?? You can 100% still have a boost leak and make boost, what happens is the turbos have to work harder to produce the requested boost. However, if you are hitting 19, that's pretty good and that leak has to be super small.... When you get into throttle does the needle fluctuate or just fly straight up there?

mo' info!

[GeeJayzS4tyme!]

12 in Hg is a leak. When you have 12, is that with or without the heat/ac on? is the clutch in? What does it go to when you have clutch engaged?? You can 100% still have a boost leak and make boost, what happens is the turbos have to work harder to produce the requested boost. However, if you are hitting 19, that's pretty good and that leak has to be super small.... When you get into throttle does the needle fluctuate or just fly straight up there?

mo' info!

12 inHg is dead solid. W/ or w/o heat/ac on. Clutch in, clutch out. The 19 psi isn't a steady pull. I noticed on the hwy last nite. It boosts to 15, hangs out there, and then once around 3800 hits, pulls the rest of the way to 19.

What do I do? Coat the turbo plumbing w/ soapy h2o, drive and boost, and stop and look for bubbles???

[AudiSportB5S4]

here ya go,

http://www.awe-tuning.com/pages/faq/...ain.cfm?FAQ=35

you'll need a compressor and to make that tester up, go to Home depot take the parts list with you and then follow the instructions on AWE's site. But then yes, spray some soapy water on the plumbing and see whatsup... MAKE SURE to take off the oil cap andd you take off the PCV valve of the Y pipe, and cap it just like AWE says to

[gointoscott]

I've been noticing mine isnt boosting as high, and the vacuum is sitting around 18 hgs instead of around 20 as well. Not as low as 12 like yours.

I have been getting codes for small evap leak. And I noticed my spider breather hose has been hissing a little when I bump it so I think that where my problem is. But I need to do a pressure test as well.

When you first start your car is your brake pedal hard and then after it starts it pushes in and is normal? That is what mine has been doing so that is another sign that the brake booster has a leak somewhere - where it doesnt hold pressure over night

Just thought I'd mention to try checking your spider - breather hose for leaks as well. But it could be many places as well.

[GeeJayzS4tyme!]

here ya go,

http://www.awe-tuning.com/pages/faq/...ain.cfm?FAQ=35

you'll need a compressor and to make that tester up, go to Home depot take the parts list with you and then follow the instructions on AWE's site. But then yes, spray some soapy water on the plumbing and see whatsup... MAKE SURE to take off the oil cap andd you take off the PCV valve of the Y pipe, and cap it just like AWE says to

Thanks!!!

Looks like I have something to do after Thanksgiving. Cuz I sure as hell won't go shopping!

I'll go to Home Depot later.

[RolledMySTi]

If the idle is under 20 hgs I would pressure test. Normal is between 20-22.