Brake boost comes and goes

[AUDI5000CSTQ]

Hi all.
Today I was driving into work with the beast, other Audis in the shop.
The brakes felt "funny" like a delay when I pushed on them.
Then it felt like I was stepping on a rock, no boost.
Not a good surprise going down I-5 in morning rush hour.
No CEL. Slide into Neutral and turned off car, restarted and brake boost came back on.
Then went off and on several times again, but this time CEL on.
No VAG. have appt with Hoehn Audi tomorrow.
Just turned over 47k today, but have platinum warranty.
Will let all know what it is/was.
Hay DHALL hope you didn't get hirt when the main tent went flying in B-J

[ben916]

status besides "in the shop"...

[AUDI5000CSTQ]

Well talked to Amy at Hoehn. She states that nothing major, a vacuum hose cracked and would open intermittently.
Thus the on and off brake boost and poor running and CEL. Fidelity is sending a rep out to check it. She stated they do this whenever it's over a $1000.00. A THOUSAND DOLLARS! for a vacuum hose? OMG, what do they do? Drop the engine for this too?

[ttboost]

Well talked to Amy at Hoehn. She states that nothing major, a vacuum hose cracked and would open intermittently.
Thus the on and off brake boost and poor running and CEL. Fidelity is sending a rep out to check it. She stated they do this whenever it's over a $1000.00. A THOUSAND DOLLARS! for a vacuum hose? OMG, what do they do? Drop the engine for this too?

That's the problem with troubleshooting. Could take an hour...could take 10 hours....Unfortunately, in your case, it took 10 hours to find a vacuum leak.

[MaxRS6]

That's the problem with troubleshooting. Could take an hour...could take 10 hours....Unfortunately, in your case, it took 10 hours to find a vacuum leak.

The problem is they can state whatever they want for "troubleshooting hours" with no way for the layman to authenticate or verify. Who knows- they may have found it within 30 minutes and took the next 9 1/2 hours on smoke breaks. Or...it may have actually took that long to find.

Only the shadow knows.

[ttboost]

The problem is they can state whatever they want for "troubleshooting hours" with no way for the layman to authenticate or verify. Who knows- they may have found it within 30 minutes and took the next 9 1/2 hours on smoke breaks. Or...it may have actually took that long to find.

Only the shadow knows.

Right. I check for boost leaks on my car all the time. It takes minutes, not hours. I've also used my buddies "smoke tester" once too and it's sometimes faster. You REALLY have to trust your mechanic.

[ben916]

That $1k seems a little "padded" to say the least...

[RS6-4dr911]

Hope your warranty isn't like mine - they don't pay for diagnostic time. Hell, my guy replaced ALL the vacuum hoses for far less than that. I predict a fight with your warranty company.

[ben916]

um, John???

[AUDI5000CSTQ]

Picked up the Blue Meanie on Wednesday.
Runs great. The hose in question was under the intake manifold. My cost was just my deductible.
I asked how much this would have cost? About $1500.00 was their answer.

[p3u]

Picked up the Blue Meanie on Wednesday.
Runs great. The hose in question was under the intake manifold. My cost was just my deductible.
I asked how much this would have cost? About $1500.00 was their answer.

I have vac leak under my manifold as well, wonder if its the same piece that failed on mine...

Do you happen to have the part number and price of it?

Thanks!

[AUDI5000CSTQ]

P3u
Amy from Hoehn Audi left me a voice mail stating the part that went bad was
058133753D
Dont have the price but hope this helps, and if it's the same be very careful with the brakes.
They will come and go.

[snoopra]

Here's a pic of the part/location(looks like a "Y" fitting)

[SIKAudi]

Awesome! this has been extremely helpful will post progress of testing tomorrow.... and perhaps a tech article on the repair. the pis and scats have been great you guys rockkkkk.

[dmross]

Bump.

Driving to work this morning, car is running like a champ. I cruise through an intersection following a car and almost rear ended him because my brake pedal went rock solid. I guess that is the proverbial "oh sh*t" moment I've seen in some of these threads. I pulled into the lot at work and shut it down. Started up and idle shot up to 3000 rpm before dropping down and hunting erratically. Vac leak for sure, I'm placing my bets this thread describes the exact issue I'm suffering from.

I'm dropping the car off at the dealership today. I'll print the above pic and hopefully save them some time. I guess it's that time of the month again for my Audi bitch, maybe I'll get the gas tank recall taken care of while I'm at it...

[4everRS]

Yikes! Hope all goes well and the issue gets resolved.

[dmross]

Just got a call from the dealership. They also think it's the suction jet pump referenced above, but they have to take off the intake manifold to confirm and have the adjuster come out. I expect it will be covered. Anything else I should look at while it's off? I did have them do the 35,000 major service this year (timing belt, water pump, etc) already.

[ttboost]

Depending on miles. check ALL vacum hoses as they tend to dry rot and leak...