boost drop!

[Guest]

hey my 00 b4 is running fine up to about 4 grand then the boost drops away to zero.. iv checked 2nd turb seems fine.. no noise or smoke out exhaust.. any help would b great cheers

[Guest boostin]

Any fault codes??

Restricted intake??

[Guest]

i havent checked the codes yet.. i dont thnk theres any restrictions. what could do that?

[Guest boostin]

I've seen a pod filter that was too small causing the exact symptoms you have.

[RSB]

1. Check that your vacum hoses are connected correctly to the EGV on the secondary turbo. Cant remember the numbers off the top of my head, but can look later if you need to know. If they are hooked up the wrong way round, you will get the exact symptom you've mentioned, with no CEL.

2. If you have a ZS sequential controller, this may need resetting. However a CEL normally accompanies this.

[Guest]

i dont think anything is hooked up wrong as it was running fine one day then the next morning it was like this. i have standard air filter so i dont think there is too much restriction... would the next thing be to get it checked for codes?

[Guest keltik]

Just to clarify here, you mean it drops to 0 and Doesnt come back up?

Id stick it in diagnostic mode (connecting green plugs together) and seeing if the exhaust and intercooler actuators all move like they should.

[Guest]

well it creeps up really slowly if ya keep it pinned but only to about 4pound

[Guest boostin]

Sounds like a blown secondary to me.

[KwS]

or a boost leak on the secondary side (had it happen to my BG5). Check all the hose clamps are tight and no cracks is pipes.

[Guest]

i had this problem when my BBOD (black box of doom) crapped itself. i was getting no boost on secondary. i had to replace the BBOD cost about $100 from wreckers.