Half Boost PCV issue?? please help

**Damon318** · 07-18-2011

ok this has been a headache for a long time and i really need some advise. i have a 98 gtp cai u bend delete other than that its stock. i have super hard crank case pressure which led me to the pcv i replaced it twice including all orings and i cant get it to stop squealing from crankcase pressure. i have half boost and odd issues with my rpms when im cruising and let off the gas. i dont know what else besides the pcv that can cause crankcase pressure? other than the low boost and crankcase pressure everything runs great? any help would be greatly appreciated.

**tylerbinski** · 07-18-2011

well, first off.

rule out the Boost Bypass Solenoid as the reason for 1/2 boost.

disconnect the boost/vac line on the BBV (bottom) and plug the line that was feeding it so you don't introduce a vac leak.

and unplug the harness... your BBV should stay constantly closed now.

see if that affects your boost.. if so you might have a poopy BBV or wiring issue.

**Damon318** · 07-19-2011

Alright I went out tonight to rule out the boost bypass and noticed two bad vac line couplers! I'm going to replace them in the morning and I really hope this fixes my issues! Any ideas on the crank case pressure?

**Damon318** · 07-19-2011

I feel kind of dumb now, couldn't the vaccum leak be causing the PVC to malfunction because of low pressure? I think I may have fixed the whole issue? I'll update in the morning when I get the lines fixed

**BillBoost37** · 07-19-2011

I'm hearing you mention a whistle and ... you did have a spring on top of the pcv right?

**Damon318** · 07-19-2011

ok i fixed my vac lines and im getting all but two bars of boost ( double what i had before) and yes i have the spring and o ring on the pcv but it still squeels! i dont know what could be the problem? i also tested my bbv its running fine

**Damon318** · 07-19-2011

one more to add i changed my supercharger oil and now im getting full boost so one issue down one more to go!

**tylerbinski** · 07-20-2011

sweet man.. did that stuff stink?

haha

**Damon318** · 07-21-2011

Originally Posted by tylerbinski

sweet man.. did that stuff stink?

haha

Yea it was pretty nasty stuff! But it helped a lot. Do you have any idea why I am still having the crank pressure? Even after changing the pcv? No codes and I just leave my dip stick out ( to relieve the pressure) and it drives fine but I really want to fix the issue

**tylerbinski** · 07-21-2011

lets try to narrow this down a bit.

the pcv system has 2 parts.

1) suck out crank case gases etc (input to Pcv valve)
2) allow fresh air into crank case to replace sucked out air

if number 2 is not working, you will be creating vacuum in the crank case and air will be flowing INTO the oil dipstick hole to replenish

I suspect that might be the case...
otherwise you could have larger issues if you have pressure in the crank case.. could be caused by poorly sealing piston rings (blow-by)

try and cover the dipstick hole with your finger while in park and figure out if its blowing or sucking.

**BillBoost37** · 07-21-2011

Pressure usually means the pcv isn't functioning. Aka it's blocked, the SC gasket wasn't cut for the pcv, an intercooler is blocking it etc.

**Damon318** · 07-22-2011

the dipstick is definitely sucking air in. so what could be my issue where would i start ive replaced the pcv and o-rings im not sure what to do next i havent had my SC off and i am stock other than my few mods listed. is there a way to track down which part of my pcv system is having the issue?

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