Ive lost 11psi of boost in 3 days. I thought boost was leaking from the BOV so plugged it with a silicon coupling and still not building boost past 10. my exhaust manifold gasket is blown i'll be replacing it today but would that cause my turbo to spool so slow? i'm suppose to get 16psi instead ive been getting around 4-5. turbo doesnt sound like it spooling as hard as it did 3 days ago. the turbine has no shaft play and doesnt spin at idle, however i can move it freely when the car is off. please tell me its something simple like an exhaust manifold gasket. thanks in advance.

 

a bad exhaust manifold will cause slow spool and less boost. How bad is the exhuast leak?

 

if exhaust cant get to the turbine then it cant spin. fix your leak

 

on average, the boost in your exhaust manifold is usually double what it is in your intake manifold. so in order to run 16psi, that's about 32psi that your exhaust side needs to hold.

think about it for a sec. you're taking 16psi of air and fuel, then blowing it up. by the time that charge leaves the exhaust port, that pressure has gone up quite a bit due to the combustion. it's not like the pressure would go down, unless maybe if you had some horrible rings and leaky valves. i dunno. don't quote me on that...

but basically, yea, an exhaust leak can defintely be the reason why you've lost boost. fix it.

 

when my exhaust manifold gasket blew, my spool time was wayyyy slow and would not build full boost

 

oh yes yall was right.. I replaced the exhaust manifold gasket last night and that **** mad a big expletive'n difference! Turbo sounds like a jet engine again, sounds way better than before gasket went! I'm still getting about 5-6 psi of boost, have a major leak somewhere but its spooling hard now.. well now i know my turbo still have a few more years left in it! amazing how much trouble a little gasket can cause..

 

get that leak fixed. you don't want your turbo to overspin. fixing a big leak like that puts the proper load on it, which prevents it from overspinning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91integraLSVTEC &raquo;</TD></TR><TR><TD CLASS="quote">oh yes yall was right.. I replaced the exhaust manifold gasket last night and that **** mad a big expletive'n difference! Turbo sounds like a jet engine again, sounds way better than before gasket went! I'm still getting about 5-6 psi of boost, have a major leak somewhere but its spooling hard now.. well now i know my turbo still have a few more years left in it! amazing how much trouble a little gasket can cause..</TD></TR></TABLE>

Def check else where for leaks. Do the obvious couplers, BOV, and WG first. For the turbo to pump out air only to leak may eventually overspin it. If you can't find a big leak get out there with some soapy water and get sprayin'