RB25DET Bolts or Plugs near Spark Plug

[Penitent_Spark]

I just have a question that appears not to have an easy answer. I have recently noticed that I was leaking coolant behind the engine on my S1 R33. I was able to trace it down to coming out of a hole above a core plug. This hole I believe functions as a drain for the Spark Plug valley. However next to the spark plugs are what look to be either bolt or plugs that coolant seems to be leaking out of.

I tried tried to unbolt these, however they are impossible to remove, what's further is that any application of force seems to strip what appears to be a Hex head. I have measured the inner diameter of the Hex head with a vernier caliper and it is 10.5mm, which is pretty odd. For the moment I have applied some sealant to this to stop the leak.

Any comments if the picture are bolts or plugs? (Please note: not my engine)

http://i49.tinypic.com/jj03ux.png

[Brett_J]

Best trick for any bolt going into alloy, or anything really, get something like a drift or similar that will cover the whole bolt without damaging it, use a 1/2" socket extension or similar, give it a good sharp whack with a hammer. I guarantee if you do it right and don't damage the head of the bolt or Hex, it will unscrew with minimal effort.
We do it with 2-3" sized bolts into cast metal that 1" rattle guns wont touch, flog it with a hammer like mentioned, undo it by hand :)

[Penitent_Spark]

Thanks for the quick reply.

Unfortunately, the previous owner has already attempted to remove this at one stage or another at so it appears, as there is little thread left on these for the Hex bolt to actually make contact. So for the moment I have just sealed the edges and will monitor what happens. I was just wondering if these are bolts or plugs, if they are plugs I will leave them merely by. However If they are bolts, I may have to use a stud puller to remove them and place new ones in.

Thank you for the tip though, greatly appreciated.

[ossie_21]

Thinking back to when me & a mate pulled apart my 25, I think they might just be plugs... If you imagine where the head joins to the bottom end, they couldn't go very far down

[Penitent_Spark]

I believe they are plugs as well I would just like to receive a consensus. I have applied some gasket sealant around that area, if they are plugs I will leave them be and not try and get a stud remover to get them out.

Thank you for the reply