HELP! Leak in interior wall

Tomd983

This is my first time posting here and I joined specifically for this.

During the week I found a large crack in one of my interior walls, one of my upstairs bedrooms to be precise. Initially I thought it was a leaking radiator but I have now identified it as a crack in the wall behind the radiator. The rad is now off the wall and I can see the crack. I've filled in the crack on the inside with a Sand and Cement mix I bought in Woodies, I thought it would do the trick but with the heavy rain last night I spotted some damp patches in the wall.
There was a crack on the exterior side of the wall at around the same place and extended a bit farther. I've filled that in with polyfilla exterior filler. I even put some filler along the underside of the window sill and on top of the sill too, just to be extra safe. The filler is waterproof too. The outside wall has pebble dash render on it and I've filled in every crack that I can see but there is still moisture getting in, granted now it seems to be a lot less.
I took on the window sill off on the inside, just to see if there was anything I could see. The best that I can tell is that the wall is constructed as follows, a cinder block on the outside along with another on the inside and some kind of aggregate in between. There is definitely moisture in between the blocks because I can feel it. The crack on the inside wall is about 10 cm below the window and extends horizontally almost from one side of the window to the other.
The side of the house with the crack is getting hit by all this bad weather, every time it rains some moisture is getting into the wall.

Plugging the leak on the inside is easy enough but I cant seem to stop moisture from getting in from the outside.
What can I do to prevent water seeping in from the outside wall?
Is there a way to check where and if the pebble dash is allowing in water?
Would I be able to remove the concrete blocks on the inside wall without compromising the outside wall?

Any help would be appreciated and is really needed, thanks.

dpofloinn

Hi Tomd

I think you should contact an engineer asap I dont think there is a diy remedy for your problem you are literally just plastering over the cracks

Situation

Can you post a picture?