Hi having read through multiple threads I think I have found the source of my multis problem. Just an update it wouldn't rev above 3000rpm and the EML is permenantly on.

This is where I am at the moment. Turbo actuator was not moving so disconnected the black pipe (with permanent suction) and the red pipe from the ?overboost solenoid, connected them together when the engine was running and the actuator was seen to move with the pipes pressed together.

I guess from this that it is the ?overboost solenoid that is faulty, either electrically or mechanically.

My mechanic said that I needed to replace the waste gate solenoid. My question is...are the waste gate solenoid and the overboost valve the same component?

Also where can I purchase a new one from?

Many thanks,

John.

Replying to a post in 2014!

Did you ever find out if the Overboost solenoid was the problem?

My Twin Air panda will go into limp mode trying to accelerate past 75 in sixth.
When fault finder picks up a code it points to Overboost Solenoid.

Hi,

I had a similar problem on my Multipla 1.9JTD over the last few weeks, aka P0046 error code. I did test the solenoid, and the valving didn't work so I replaced it, but I also had a MAF sensor fault being reported too, aka P0101, and I'd swapped this for a new one previously.

Anyway, it didn't alter anything, and it turned out to be the vacuum pump unequal tee was slightly dislodged from the lower rubber hose (it is 16 years old and age hardened with no clips on it as per OEM set up), and I struggled changing the EGR valve (after reading all the forum guff), which still didn't change anything BTW, and must have disturbed it.

I relocated the tee by 3mm max and rotated it into the cutout in the lower hose, and the vacuum leak was eliminated, and all was good again. Engine light went out. I have no idea if this snippet is of any use to you, but my gutless behaviour was linked to the vacuum being too weak, simple really, and this will flag error codes, as the ECU doesn't expect this.

Good luck
Mike

As far as I know there is no waste gate on a multi. The turbo is a variable vane type. The actuator ( the silver bellows type thing below the turbo) changes the amount of boost on the turbo. Its driven by vacuum from the inlet manifold side. So any leaks on the pipe from the solenoid to the 'bellows' will stop it from working. The 'Bellows' or actuator as we should say, also seize up over time. I got one for about thirty quid, swapped it over and it made a big difference to the engine.