Actuator

[aa120n]

hi, iv had a problem with my turbo being stuck in limp mode for a while, and wasnt getting anywhere trying to fix it, as it could have been a number of things causing it. i read on the imoc forum that  if i clamped the hose coming from the turbo to the actuator, and carefully took it for a spin (un-controlled boost),  he said if the boost went above 7 psi  it was the V.S.V.

If it didnt reach 7 psi it was other things like actuator, or knackered turbo..

so i did this and the boost was fine went well past .5 bar, i didnt take it too far incase i knacked it.. even though it was tempting as i loved it and had a massive smile on my face! :D

so its defo the V.S.V ??

would you guys agree with this? just wanted a second opinion, iv checked it and it doesnt look like ist disconected, so should i buy a new one?

any  thoughts welcome as i dont know much about this stuff....

thanks!

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The VSV is like a stock bleed valve !!

you actuator is controlling your boost, when a certain level of boost is reached, the actuator opens the wastegate to bypass some exhaust gas, and bring the boost down, then it will close when its back within boost limits, and open - really quickly to keep the boost at the correct level.

now the VSV bleeds a bit of the boost pressure away from the actuator - basically tricking it into thinking there is less bost, so the actuator stays shut longer (so does the waste gate), and the boost is allowed to increse a bit more.

Now if you got your self a bleed valve, or a G valve - you can bleed away more of this boost (G-Valve prevents boost reaching the actuator - but lets not confuse the matter yet !!) tricking the actuator more - so you can run m even more boost !!! (if this is done the VSV is totaly disabled and all the bleeding will be done by the valve)

now if you actuator was knakered the boost would simply push the wastegate open, reducing your boost. !!

the test you have been asked to do does prove it seams to be the vsv that is playing up.

I would scrap the VSV (Disconnect ot), and get a G-valve / boost controller ! then you can run all the boost you like (within reason)

but there must be a reason that the vsv is staying shut (if its not knakered) - it will stay shut when engine is not up to temp etc, so make sure thats all ok before you deck it !!

HTH

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i did this test and i was still only gettin about 7 psi boost. how can i tell what the problem is now?

if it is the actuator are they easy to get hold of and fit?

and should i be looking at upgrading not just replacing it?

[shaf2000]

you should be able to get an actuator from fensport.... not sure how easy they are to fit though. i was quoted about £180 to supply and fit one previously.

[boundsw]

Yes id say it was the actuator. you will be looking abour ~£100 for a adjustable one.+fitting

I have a fully adjustable actuator on my 2.

The actuator is one that comes as standard with a stg 1 ct26 turbo. Fensport or turbo technics should be able to supply. (mines fromTT)

They are ok to fit, just a little fiddley !, and if you have a cat, id let the garage do it, because it will be near on impossible to get the arm on with a cat in the way ! (mines de-catted)

[aa120n]

would you recommend gettin an adjustable actuator, instead of another standard? with the actuator performing as it is the minute it's not damaging any thing else is it?