Problem with boost control
Posted: Fri May 02, 2014 5:33 pm
Hi guys I wonder if anyone can shed some light on this issue for me, my X5 (3.0d manual) has an issue whereby if the vacuum to the boost control solenoid is disconnected the car will drive fine just laggy until you hit around 2.5k and then the turbo kicks in and it's off like a rocket, if you reconnect the vacum it struggles to rev and smokes (black).
The turbo actuator is all moving fine when vacuumed is applied but when the car is revved the actuator stays in the retracted position and is not slowly releasing as the revs climb hence the turbo can't provide enough air or is stalling.
The boost control valve has been changed for a known working one, Munich legends ran diagnostics as far as they could (nothing showing) but at the time the exhaust manifold was cracked (now replaced) so they couldn't go any further.
The turbo is fine and the variable nozzle mechanism is all working, it seems that it is something to do with the control of the boost solenoid,.......could it pos be map sensor or air flow meter?
Sorry for the long post but this fault seems to be so minor yet so far has eluded me >: :blink:
The turbo actuator is all moving fine when vacuumed is applied but when the car is revved the actuator stays in the retracted position and is not slowly releasing as the revs climb hence the turbo can't provide enough air or is stalling.
The boost control valve has been changed for a known working one, Munich legends ran diagnostics as far as they could (nothing showing) but at the time the exhaust manifold was cracked (now replaced) so they couldn't go any further.
The turbo is fine and the variable nozzle mechanism is all working, it seems that it is something to do with the control of the boost solenoid,.......could it pos be map sensor or air flow meter?
Sorry for the long post but this fault seems to be so minor yet so far has eluded me >: :blink: