1.9 cdti boost sensor...read on!

[bladeage1]

When cleaning the boost sensor fitted to the inlet manifold the following has worked for me......

spraying the boost sensor with cleaner etc will not actually really do anything, it will clean the top part of the sensor but will not clean the important bit!

I found that when I cleaned it initially it all looked very clean and new,but on closer inspection I realized that the bit that moves inside the conical housing goes further deep down inside the conical housing.

opposite the sensor inside the conical housing is a hole, insert a straw into this hole and wiggle it around a bit and you will unblock it.
You now need to take a can of wd40 with the straw nozzle and push the straw into the hole and spray it loads, you will eventually see wd40 coming through the opposite side of the sensor, meaning that the sensor is now free to move around and you have removed all the carbon deposits from the tunnel where an air vortex is supposed to be.
Finally spray carb cleaner into the hole you have just unblocked (opposite the sensor prong) and it will flow out of the sensor prong side.

Putting it simply.....

there is what can be described as a "U" bend (same as a sink!) inside the sensor (conical bit!) and that if blocked stops the sensor prong from moving therefore restricting it's sensitivity to pressure, hence boost will be low if it is blocked.
cheers.

[mally]

Nice find. Shame you didn't take any pictures as it would make a good addition to the 'How to'

[bladeage1]

Hi,
I will when time permits take the boost sensor out and do a run through with pictures, it is a good idea as I am not sure everyone is cleaning it properly,the first time I cleaned it the cart ran better, this time it restored the car to normal. I am now convinced it was this that was causing all the problems, the turbo boost restriction was causing the engine to retard because of the gasses building up making the engine breathe when under acceleration.
The short cause is deffo the EGR valve as the sensor was crudded with carbon....and I mean really crudded!