Originally Posted by adamS2RST
Leaky core plug by the looks of things
Easy enough to fix mate, you can get a whole core plug replacement kit for the cvh from Burtons for a few quid!
Only hard thing is knocking the old one out the block, not too much trouble tho!
Who told you this?
knock the old one out by using a screwdriver and a hammer, place the screwy in the centre or at the edge on the inside of the core plug and give it a dunt, it will disfigure it and allow it to come out easy!
https://www.burtonpower.com/dets_pro...p=09027&PSet=1
Their the chaps your after.
then fitting all you need to do is chap them in gently, preferably with a rubber mallet or a piece of wood across the tops so they go in evenly and square!
MAKESURE IT IS THESE LEAKING FIRST!!
Also check around the water pump.
P.s. cant think of a reason why they would leak other than general wear and tear as you say, makesure your coolant mixture is correct as the only other reason they may leak or pop out is if your coolant freezes, it wil expand and look for the weakest point to come out.