astra coolant hole on engine

[sadham]

I have an astra h 1.7 cdti 55 reg. It developed a coolant leak (as you put coolant in it came straight back out) I've managed to find the source of the leak it's this cap that goes into the side of the block:Coolant leak

Is this supposed to just slot back in or am I meant to seal it with something if so, what?

[Jesus325iTouring]

If I recall they just push in, I had one blow out on my old MK1 Astra SR.

[maxfield]

They should knock in, rare they fall out, there purpose is to pop out if the engine freezes up.

[Jesus325iTouring]

Mine rusted through, this was back in the early 90's, car over heated and I hitched a lift to the nearest town with a man who looked like Fred West

[Satan]

Mine rusted through, this was back in the early 90's, car over heated and I hitched a lift to the nearest town with a man who looked like Fred West

You must be related........

[sadham]

Should be okay to just put a socket piece onto the end and tap on that to push it in?

Not liking the astra, had to take far too many things out to get to this leak and the manifold is fully caked up with soot don't think it's ever seen a motorway in its life.

[biffer]

The central part,when new, should be domed/convex, so that when u tap it with your hammer to seat it,the blow will flatten/expand it to fit the hole without needing a sealant.

So it may be something that's only meant to be used once.