[s-cars] Vacuum leak

[Cory Pio]

Yes it's low vac at idle engine used to pull 20 now only 15 when fully  
warmed up. Sometimes as little as 12 when cold. I'm running a stock  
k24 here. It's more like the turbo doesn't spool with light throttle  
anymore. I hear air escaping out what sounds like the bpv or possible  
the wastegate. Before the car would boost with any throttle really  
always coming out of vacuum. It builds full boost when floored like  
normal but moderate throttle could alway spool it up to 15 and hold.  
Not anymore. It defiantly sound like the bpv or wastegate aren't  
operating properly. I believe low vacuum/ leak is the problem. My  
mechanic says hesistation  but that's cause he only floors it when he  
test drives it and doesn't test normal boosting conditions.

Sent from my iPhone

On Dec 11, 2009, at 9:57 PM, Robert Myers <bob at chips-ur-s.com> wrote:

> *This message was transferred with a trial version of CommuniGate(r)  
> Pro*
>
> The "vacuum pump" under the rear seat operates the pneumatic locking  
> system and has nothing to do with your boost or lack thereof.
>
> If I read your complaint correctly I think you are complaining that  
> your engine is showing turbo lag.  This is 100% normal for a  
> turbocharged engine,  If boost is not coming on as early as it used  
> to and/or it isn't getting as high as it used to then you may well  
> have a leak in the induction system.  There are several cute tricks  
> to locate such leaks.  Some work in one case but not in others.
>
> If you have a leak while idling (the leak is open at low pressures)  
> try spraying ether based starter fluid over the plumbing while the  
> engine is idling.  If ether hits the leak some of it will be drawn  
> into the system and the engine rpms will pick up.  This can help  
> find such a leak.
>
> You can construct a simple gadget from a 4-6" piece of 3" PVC pipe,  
> a 3" cap, some PVC glue, and a tire valve.  Use this gadget and some  
> shop air to pressurize your induction system to perhaps 7-10 psig.   
> Listen for a hiss sound from the plumbing and track it down.
>
> Of course if you have a BIG leak you can't get enough air in the  
> system to inflate it even a little.  Start looking for likely  
> leaks.  The very first place to look is the Michelin Man hose (from  
> the crossover pipe to the intercooler inlet) and closely inspect it  
> for leaks - take it out and flex/bend/twist/etc to expose and  
> potential leak. if it isn't there then do the same with other  
> portions of the system.
>
> Do not ignore the small tubing connected to the water trap.  Earlier  
> s-cars look for the trap high on the engine side of the firewall  
> near the rear of the engine.  It is a little larger than a 35mm film  
> cannister.  Later models have the trap located under the carpet near  
> the ECU.  Trace the MAP hose back from the ECU to find the trap.
>
> Bob
>
>
> At 09:36 PM 12/11/2009, you wrote:
>> *This message was transferred with a trial version of CommuniGate 
>> (r) Pro*
>> Alright guys
>>
>>  Im thinking a vacuum leak might be giving me wastegate/ bpv
>> problems. My car pulls about -15 hg in.  When fully warmed up. It  
>> used
>> to do 20. So my question is my car locking system and the vacuum pump
>> under my rear seat a good place to start looking for leaks?
>>
>>  My symptoms are my car doesn't go into boost right away . The
>> wastegate or bpv seems to be staying open unless you really get on  
>> it.
>> Any help would be much appreciated.
>>
>> Thank you
>> Cory pio
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