Actuator stiff?

[Tomsy]

Hi all,
Im a fairly new member and i love this forum, i own a audi s3 AMK and have done a few bits and pieces, best of all was the B5 TIP but to get to the point i get the code that tells me my car is overboosting and i am thinking my actuator arm is very stiff. I have checked all pipes to the actuator and n75 and they are fine + alot of split pipes and plastic connectors replaced so i think my pcv system is leak free (not smoke tested though). Does the actuator arm usually move more freely?
Ta.

 

[JUS3IN]

no its pretty stiff, your can use a lenght of silicone hose and get a tyre valve, cut it down and force it into the pipe and put the other end on the actuator. then pump it up to 35psi and see if it drops. overboosting can be caused by a leaking actuator. when you hit full boost the actuator opens the penny/hole to stop boost rising, if its diaphram is split it wont open and the spring will hold it shut. also try unplugging the n75, if it still overboosts its a mechanical issue, i.e turbo/actator or pipework. if it doesnt overboost with it unplugged it could be boost pressure (map sensor) sensor amongst other things. worth taking the tip of and looking at the blades too.

 

[Tomsy]

Thanks bud, i took a look at the blades and also checked for any play when i put the new b5 tip on, i have disconnected the n75 and it still overboosted so i will pressure check the actuator the way you said (which is a great tip) and see if it holds pressure.

 

[JUS3IN]

no problem, learnt it all here!-)

 

[Tomsy]

no problem, learnt it all here!-)

Thanks mate.