MP4.2+6.0

Here is a link to the "how to" typical replacement arms, when the arms actually snap. To me though snapped arms are more a symptom (not always present) than the disease. The disease are binding seals and bearings in the manifold. Anyway, in the pictures deeper into this how to, you see the plastic lever arms below the arm related rods. You need to confirm it moves and then spring retracts at those lever arms. Per their explanation, it sucks vacuum at idle/start up, so they should move just based on that. Been too long without them...the W12 was not "blessed" with this long running 4.2 V8 NA implementation and turbos now make it obsolete.

http://www.gruvenparts.com/content/P...e_Link_DIY.pdf See 4th page where the actual pictures of a motor are, and the testing by just starting car and looking for movement with start up.

Jack88

Alright, looked into it, both will turn, but the one on the driver's side is stiffer, taking a fair bit more effort to turn. No apparent damage to the links, they still seem fine.

MP4.2+6.0

Per the web link, now try starting engine to see if it in fact pulls the driver's side one tight at idle via the diaphragm action. If not, it is too bound up and then you don't have the intake working right at lower RPM's on that side. Eventually it is a goner, but meantime try regularly applying a good penetrant at the shaft to try to free it up. The seal is likely failing from the inside though.