My name is Nektarios, I'm 23 and i am a big fan of yours since many years ago!!!
So Scotty, I Leave in London and I drive a Vauxhall Corsa D 1.0 of 2009.
One day while I was returning home from my work my water pump gasket failed. As soon as I got home I bought a new one and replaced the old one! But since then every time the coolant was getting hot I could hear bubbles in my coolant expansion tank and the coolant started to dripping from the top of the expansion tank. I changed the radiator, and the expansion tank cap (my radiator doesn't have one), I installed a new thermostat, I checked the hoses and I changed the head gasket as well BUT still the expansion tank is full of bubbles and the coolant is expanding and overflowing. Evenmore, i took extra care while i was cleaning the coolant passages on the engine block and the head block.
I also noticed that the lower radiator hose was not hot at all and that almost every time I turn off the engine my coolant dissappear's from the expansion tank! What could the problem be in that case? the engine didn't have any cracks or needed sanding. I can still drive the car but not for long because the bubbles are coming up and I don't want to overheat the engine.
I am thinking to install the old water pump on the car as everything started when I changed it. (When I bought the new one I took my time to compare it with the one I had on my car and they were identical.)
PLEASE HELP ME BECAUSE I AM DESPARATE. I am a student and I need the car to go to work! You are my only hope! Also the car has an expired MOT
Thank you for your time to read this message and I will really appreciate it if you suggest me to do something !!!