my just purchased volvo xc70 shows -10.5 on diagnostics for boost pressure
had it diagnosed as leaky actuator diaphram !!
no smoke out exhaust in neutral revs up OK
would leaky actuator give me no turbo
also checked actuator manual operation its got resistance pushing away which means its closed i think
can you point me in the right direction

 

If you had an issue with the actuator I would think you would get overboost since the waste gate wouldn't be able to open properly. Vacuum is fine and expected in idle, and 0-low throttle conditions. Is the car driving fine or are you getting the car check for an issue?

 

thanks for replying the car drives as normal like a car without a turbo if you say wastegate closed due to faulty diaphram
then either the turbo is seized so its not spinning do you have any posts on removal and installation of turbo

 

I wouldn't go that far just yet. No check engine lights or anything? Also what is that -10.5 value you are giving? Did you take it to a good volvo shop or dealer to get it diagnosed? If you had bad boost pressure you would get some codes in VIDA whether you had CEL or not.

 

hi, diagnosed at volvo workshop as leaky diaphram
they suggest replace turbo engine has been serviced for the last 10 years 225ks on clock
i put my torque app and bluetooth adaptor to read the data
on boost it showed minus 10.5 when increased the revs it didnt move
possibly the car needs to be in auto so the boost works ??
no alarms

 

You need to be in drive to gain any boost. Boost is limited in 1st and 2nd, but you'll see a change in pressure in 2nd if its working properly. If its a leaky diaphragm it can be replaced without doing the entire turbo.

 

thankyou what worries me is that if theres no vaccum on the actuator side and we have tcv and turbo solenoid connected to that side of wastegate with vaccum hoses wounld that be the reason
there no signal so the boost is not comming on ? another commemt is the wastegate actuator seems to be closed !!
i put hand on it and there is pressure on the rod i am pushing the rod away from actuator
surly if the actuator is shut we can have boost if turbo is still working ?
noticed theres oil on the cold side of turbo sittng on the housing looks like leaking oil from above