overboost - turbo pressure error
How do I fix the vacuum all the time problem?
When I take off the hose from the boost regulator valve it DOES release the pressure, even with engine off...
That should not happen?
Overboost problem is actually simple to identify and solve.
turbo vanes are stucked in one position:
-either stucked vanes
-or vacuum all the time in pipe that goes in vacuum driven actuator mounted on turbo housing.
stucked vanes...pretty rare case but I once put link to this story, with all the pictures.
vacuum all the time?? how?VNT solenoid does not allow air to come in pipe that leads to turbo.
so vanes in turbo are always in position for low rpm...which means, turbine spins easier and faster.
and goes like this until it reaches some point (usually 2500-3000rpm) where pressure is so big, it triggers MAP sensor alert.
EASIEST way to test:
when engine is off, remove small diameter rubber pipe that goes from VNT solenoid to turbo.
I usually remove pipe on side of VNT because it is easier to reach
if you hear sound of air sucked in that small pipe that means that vacuum is present. it should not be if engine is switched off.
one more way:
do not perform previous procedure. just take with some tool rod that moves vanes inside turbo.
if you can not move FROM turbo, if it is already moved, then vacuum is present also.