i finally got around to replacing the boost solenoid yesterday. also cleaned the map sensor, which was coated in oil. unfortunately it made no difference. still no turbo boost :(

  

7 hours ago, jcr said:

finally got around to replacing the boost solenoid yesterday. also cleaned the map sensor, which was coated in oil. unfortunately it made no difference. still no turbo boost :(

Is the turbo actuator rod moving with engine start yet?

If not, there must be a problem with the vacuum system somewhere, or the actuator is jammed.

If possible, try direct connection of the vacuum hose (that goes from the vacuum pump or brake servo, to the solenoid) to the turbo actuator. That would test for a broken wire or electrical problem powering the solenoid,

If the brakes work properly, the vacuum pump must be ok. If the vacuum hose hisses when pulled off, and does not move the turbo when connected to it, then the actuator must be jammed.

Also a log using Forscan while driving might show if the turbo is working partly, or not at all.

 

thank you once again for your advice peter.

i took the hose off the bottom of the actuator and got the girlfriend to start the car. there was no air at all coming through  the hose. was able to follow the hose for a short way but then it disappears into the engine. am currently trying to find a diagram of the path the hose takes online. 

6 hours ago, jcr said:

am currently trying to find a diagram of the path the hose takes online. 

It goes to the boost solenoid valve. Though exactly how, I have not seen!

From another thread:

The valve has a 2 wire connector and 3 pipes on it.

The pipes are from the left, vent (to the small air filter on the end of a pipe at the back of the engine bay, just under the wipers), vacuum out to the actuator and vacuum in from the vacuum pump via a reservoir (black plastic blob left of the valve).

----

(The vent pipe may also go to a spigot just after the airbox, opposite the MAF, but this vent pipe is not likely to be the cause of the problem)

This is from:

There is a photo of the valve in that post.

thanks peter.i managed to follow the hoses to the filter and the vacuum pump, its the one to the actuator thats hard to trace - the one i want to check!

looks like its a case of removing several parts from off the right side of the engine engine. a bit of a headache unfortunately. 

Quote