is ther anyway i can use pink normal maps in UE4?
What you are trying to do? Material editor allow you to input any kind of tangent or world space normal you want.
Why do you want to use it in the first place? Generally a Normal map that is pink like that is missing it’s blue channel where the height information is stored. Since the blue channel is just vertical height information you can re-make this data in the shader. UE4 does something similar to this when using the BC5 compression method for Normal maps. The BC5 compression method removes the blue channel of your normal map and leaves only the red and green ones which would make the normal map look pink. With that said you could probably import this into UE4 but you will have to reconstruct the height information in the shader and there could also be other issues that you run into with lighting now working properly.
Last time i tired using those normal maps in UDK they did not work
That is probably because you need to make sure that engine knows how to work with Textures like that. Again what are you trying to do with a pink normal map that you can not do with a standard one.
Is there any text tutorial or documentation where i can find how to bypass this? Its because there is a game where i took model from it has those normal maps and they were rendered from zbrush and in some places like face they look better than the ones i generated from crazybump
Not sure, but xNormal is probably the best choice at converting them to regular normals.
Any details? I dont work with xNormal 
Nah sorry, I’ve never even seen a pink normal before 
But it’s free, works great and the site does have docs I believe.
It’s quite simple.
z = 1.0 - sqrt(x^2 + y^2)
No there is not any that I know of that would show you how to address an issue like this. What you could probably do is take the pink normal into Photoshop and using the NVIDIA Normal Map tools convert it to a normal map.
ok thanks everyone, i will try 
There are Mip 13 normal textures, when exported i get this error
Resulting in UE removing the blue channel. Is there a way to re-add the blue channel within UE?
If you are sure they are in tangent space then you just need to add math as Jenny Gore said. Perhaps there is even a node like that already available.