Core plug help

[jeffstoo]

Hi Guys
The core plug needs replacing at the back of the cylinder head on my S2 and I am having trouble getting the old one out. Anyone got any tips on the best way to remove it.
The engine is in situ so space is a bit of an issue. Any advice gratefully received.

[steve briance]

I did the ones in my engine block while it was on the stand. They were REALLY tight. I ended up chain drilling a series of holes and once joined together, i could get a lever in there to pop it out. Some needed bashing a bit. Refitting was easier using a socket to drive them in squarely. Some say for removal use a pin punch on one side to try and 'swivel' the plug in its hole and then pull it out but the one on the back of the head is so small I'm not sure if that will work. If you are concerned about drilling and letting metal particles fall into your water channel (i didn't have this to worry about) then maybe you can try a cold chisel and try and attack the plug from the side to fold it in on itself. Best of luck - doing it in-situ is not something i would fancy

[Error404]

The one on the back of the head is bad enough to get out on the stand in my experience, as you have to be careful not to damage the soft cast ally.
I drilled a series of small holes on one side and then punched through with a chisel, then fashioned a hooked attachment for a slide hammer and and knocked it out. It took some grief but came out eventually in one piece.
As Steve said not something I'd fancy in situ to be honest. I'd probably try the same technique, but with a 90° drill attachment and make a sturdy C-shaped drift to knock it out.

[newsh]

I did mine in situ on the coupe, the Wagner reverse manifold helps as there’s more space back there. From memory I got a self tapper through it quite easily as it was rusty, levered on it a bit, banged a screwdriver through the hole, levered a bit more and managed to pull it out.

[jeffstoo]

Thanks for the replies. I spent a few hours on it last night and a few hours tonight. I have had to stop now as the swear box is full, also my hands and arms are starting to look like raw steak. I have managed to drill some holes in it. I have tried some self tapping screws and made up a curved leaver a bit like a nail puller but the screws are pulling out. I am up to 5mm screws at the moment. I like Errors idea of a C shaped puller. I think I will try something like that but with some sort of puller arrangement as there is no room for a slide hammer type thing. Its good to know newsh has BTDT, it gives me hope. Will let you know how I get on.

[newsh]

The bolts that hold the front wings on are big self tappers

[steve briance]

I wonder how about welding a bolt on to it? The momentary heat while doing it might well expand the seal and break any corrosion holding it in? I'm a fan of welding nuts onto studs that have snapped flush, never failed to work yet.

[jeffstoo]

Hi Guys
Well I managed to get it done! It took some time but I got there in the end. Like a lot of jobs if I had to do it again I think I could make life easier for myself. I am with you Steve on the welding of nuts/bolts, didn’t get to try it but a good idea. Thanks to everyone for their input.