Ive been replacing all the hoses in engine bay at the moment. And whilst pulling things apart accidently broke the part below:




and where its from:



anybody know what this in and what it does? if its just a stopper could it just be blocked?

thanks

 

the car is a 1988 series 4 turbo II

 

lookls like a vaccuum cap.. unless your hiding a part of it

 

I thought it was a vacuum cap too but it looks like it may let air come thru - maybe like a little vacuum filter, or maybe it holds a certain amount of pressure?

I'm not sure...