Seized PCV retaining screw
Thread Starter
Super Member
Joined: Feb 2010
Posts: 612
Likes: 112
2014 C63
Seized PCV retaining screw
I'm trying to change the PCV but that T30 screw that holds the PCV to the manifold is being a real pain. I was able to get it turned about 15 degrees but then it gets tight again. I worked it back and forth a few times, but still no dice getting it to unscrew any more than that. I'm afraid to force it thinking the screw will snap or worse the threads in the manifold will crumble into dust. I just tried putting some penetrating oil on it and will try again in a few hours. Any other ideas on this?
Junior Member
Joined: Nov 2021
Posts: 24
Likes: 9
2011 C63
That is a bit scary, I had one that was pretty hard to get out but eventually just went for it but would be worried that the magnesium is corroded and it will pull out the threads which worst case you can rethread a size larger and either enlarge the hole in the pcv or put in a thread repair to resize it back which would be pretty easy assuming you are doing this removed from the car. I would keep working it back and forth and lubricating it and see if it will work free, maybe a little heat could help also.
Member
Joined: Jun 2020
Posts: 208
Likes: 47
AMG C63
I'm trying to change the PCV but that T30 screw that holds the PCV to the manifold is being a real pain. I was able to get it turned about 15 degrees but then it gets tight again. I worked it back and forth a few times, but still no dice getting it to unscrew any more than that. I'm afraid to force it thinking the screw will snap or worse the threads in the manifold will crumble into dust. I just tried putting some penetrating oil on it and will try again in a few hours. Any other ideas on this?
From this experience it would appear that you need to use a lot of force...dont quote me though.
Junior Member
Joined: Nov 2021
Posts: 15
Likes: 1
2013 C63 AMG W204
I'm curious if I need to remove it from my C63 to replace the pcv.
Thanks in advance
Thread Starter
Super Member
Joined: Feb 2010
Posts: 612
Likes: 112
2014 C63
Some claim it can be done but I don't see how. I removed the manifold. However, I had a HELL of a time getting a the connectors and rubber hoses disconnected. There is a plastic hose that comes through the firewall into the rear of the manifold. You squeeze it to remove which seems easy enough except I couldn't get it come out completely. Fear it would break, I left it intact and propped up manifold with some wood block to remove the PCV itself. I then re-seated with new gaskets and bolts following the tightening specs. My PCV was OK, but I could tell after handling the new one it was definitely more brittle. You'll need to re-seat the manifold from back to front. Make sure to keep your throttle body connectors (there are 2) out of the way when working on it. I cracked one of mine because I set the manifold down on top of it.
