ND_eclass

I believe a 6mm or a 1/4 works on this.
So I'm needing help, for some reason the bolts on the left(driver's side) bolts on the spark plug connectors seem to be stripped. I'm astonished at how the this could be as it should be the same size as the right side bolts. The right side(passenger's side) spark plug bolts came off without much effort. My question is that, I've tried to used a 12 pin 1/4 connector to turn them loose, but no avail. I'm looking for suggestions to getting them off given the tight space. Thank you in advance on responses! P.S. I can also post the PDF's of how to change the spark plugs without taking the manifold in w212 2012 and up.

ND_eclass

By the way, I feel like these screw heads are so soft as I mean, it's not like I kept trying to un-screw them. I'm a bit tired from this project, but I'm half ways, 3 plugs left.

JohnnyC

Well yeah they are soft, only 8.8 Grade. You will need to use extractor sockets or sometimes called turbo/twist sockets. They are helical impact sockets that you pound on and turn counter clockwise. If you don't use a E-torx socket you will mess up the head, this includes spline sockets. They are not for E-torx despite some places advertising it as interchangeable.

ND_eclass

So I tried using the socket "extractor." Out of all the hardware and auto speciality stores, only Walmart had them in stock online. Anyways, they still will not work unscrewing those rounded screws, and since it's a tight spot.. I'm just tempted to just be okay with changing only the three spark plugs on the passengers side of the car. Still, any suggestions that could work? I was thinking of using a "Dremel" but then again, the bolt is fastening a rubber spark plug socket.

JohnnyC

take off the air resonator plenum.

- Mover -

If you have room, try cutting a straight groove on the screw head so you could ratchet them off.