Xpresion

Can anyone here she some light on the what this is? its like a valve or something behind the supercharger near the intake. I noticed it when i removed the charged air tanks to clean them out as i had too much oil in the engine and thus resulted in too much blow by into the tanks.

i spotted this black valve looking thing and to my surprise you can pull on it and it seems to open up? its very strange and i would like to know if that's the proper behavior of it? and most importantly, whats its purpose?

Thanks guys

viper04

If what i think you are talking about in this picture, it looks like a vacuum port plug. On the E55 because of the SBC that port is block off. On some 55 like the S55 that post is open and used as a brake vacuum port.

Xpresion

hmm interesting, it makes sense as the car has no brake booster as such cos of the SBC.

It doesn't feel like a plug. and if it is i wonder if mine is lose? or if its a spring loaded mechanism and mine is on it way out? because i can easily pull it out. i understand the engine is under vacuum where that port is. and at nearly 100% of the time as its on the intake side, but still i wonder if any air leaks past it? because that potentially can cause the same issue as having a bad intake to throttle body seal ring. u know, the one that seals the intake to the throttle body.

if anyone can confirm exactly what it is and if it should be tight / firm that would be great.

Forrest Gump 9

Yup, a plug. If you worry, put a dap of glue on it and plug it back. Or weld it shut but that'll require you to remove the sc.

JoeNobody

Yes it's brake booster port. It's used on S55/CL55 as they don't have SBC

layzie12g

Use a little RTV and put it back in. Allow it to dry and you'll be fine.